IAEA-TECDOC-828

Use nuclearof techniques in studying soil erosion and siltation

Proceedings of an Advisory Group meeting held Vienna,in 26-29 April 1993

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US NUCLEAF EO R TECHNIQUE STUDYINSN I G SOIL EROSIO SILTATIOD NAN N IAEA, VIENNA, 1995 IAEA-TECDOC-828 ISSN 1011-4289

© IAEA, 1995 Printe IAEe th AustriAy n i db a October 1995 FOREWORD

wels Ii t l known that soil erosio lakd nan e siltation frequently create serious problems, especially in arid and semi-arid zones. Inappropriate human activities are. in many cases, factors accelerating these problems bees ha nt I .reporte d that sinc e seconeth d World War. more than 3000 million acre f agriculturaso l land have been damage humay db n actiond san may prove costly or impossible to reclaim.

Fallout 137Cs from nuclear weapons testing has been used in soil erosion and sedimentation studies since 1960. More recently. 239-240p e samm f uO e origine th wels a ,s a l cosmogenic radionuclides Pb, Be, Be, Si, C, A1, C1 and Ar have been used for 210 7 10 32 14 26 36 39 the same purpose. Even Chernobyl Cs is a promising tool for sedimentological studies in I37 areae th s affecte releasee th y db . More than five hundred papers have been published during las e year0 th 3 t thin so s subject resulte Th . s obtained have proved that these techniquen i n sca many cases provide information on erosion and sedimentation processes which cannot be obtained using conventional techniques.

Important progres s beeha s n made during recen te utilizatioth year n i sf o n environmental radionuclides for erosion and sedimentation studies. However, most of the studies have been carrie specialln i t dou y selected environments with ideal condition orden si r to facilitate the interpretation of the results. Only very few applications have been reported dealing with the study of real problems in non-ideal sites. There are still some knowledge gaps which fillee havb o det befor techniquee eth appliee b n moro sca dt e complicated real situations.

This advisory group meeting (AGM) was held to discuss the present status of these nuclear technique o t defin e needd th r ean futur sfo s e e developmentth f o e On . recommendations of the AGM was the implementation of a CRP on this subject. As a consequence of the meeting, a CRP on Soil Erosion and Sedimentation Assessment Studies by Environmental Radionuclide theid san r Applicatio Soio nt l Conservation Measures wile b l starte 1995n di .

This publication compiles papers presented by the invited experts during the meeting and an updated bibliography on the use of 137Cs in soil erosion, siltation and other related environmental studies.

. PlatA . a BedmarMr ,Divisioe theth f no Physicaf no Chemicad an l l Sciencese th s wa , IAEA's scientific secretar AGMe th f y.o

It is expected that the information provided will be a useful guide to scientists involved in research/developmen nucleaf to related ran d technique erosion si siltatiod nan n studies. EDITORIAL NOTE

In preparing this publication for press, staff of the IAEA have made up the pages from the original manuscripts as submitted by the authors. The views expressed do not necessarily reflect those of the governments of the nominating Member States or of the nominating organizations. Throughout textthe names Memberof States retainedare theyas were when textthe was compiled. The use of particular designations of countries or territories does not imply any judgement by publisher,the legalthe IAEA, to the status as of such countries territories,or of their authoritiesand institutions delimitationthe of or of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the pan of the IAEA. The authors responsibleare havingfor obtained necessarythe permission IAEAthe to for reproduce, translate or use material from sources already protected by copyrights. PLEASE BE AWARE THAT MISSINE TH AL F LO G PAGE THIN SI S DOCUMENT WERE ORIGINALLY BLANK CONTENTS

1. SUMMAR ADVISORE TH F YO Y GROUP MEETING ...... 7 .

2. WORKING GROUPS CONCLUSION RECOMMENDATIOND SAN S ...... 8 137 bomb-testinf o e Us 1 . g2 radionuclides ( Cs, 239-240e PuB )? 5 2iopb in soil erosion studies...... 8 bomb-testinf o e Us 2 g2. radionuclides (137Cs, 239-240Pu)d an , 210Pb in sedimentation studies ...... 9 2.3 Application of long-lived cosmogenic radionuclides in studies of erosion and aggradation ...... 13 2.4 Tracer techniques and nuclear gauges ...... 14

PAPERS PRESENTE MEETINE TH T DA G FAO's programme on soil erosion...... 19 D. W. Sanders The role of nuclear techniques in sedimentation studies and some application Latin si n America ...... 9 .2 P.E. Aim, J. V. Bandeira Linking land use and reservoir sedimentation by two approaches utilizing 137Cs ...... 99 S. Mclntyre erosion 137i Csedimene d sus nan t deposition studies: ...... 1 1 1 . promise problemd san s J.C. Ritchie, C.A. Ritchie Bibliograph publicationf yo 137f so Cs studies relate erosioo dt n and sediment deposition...... 125 J. C. Rilchie, C.A. Ritchie

List of Participants...... 203 1. SUMMARY OF THE ADVISORY GROUP MEETING

An Advisory Group Meeting (AGM) on the Application of Nuclear Techniques in Studying Soil Erosion and Siltation was held in Vienna during the period of 26-29 April 1993. The AGM was attended by 18 participants from 15 Member States, and was mainly devoted discussioe th possibilitieo e t th f no s offered from sedimentological studie f environmentaso l 137 radionuclides coming from bomb testinge m , suc^ s 239-240pd a hCu an swe ^ U; radiogenic radionuclide 2iopb and the cosmogenic radionuclides 7Be, 10Be, 14C and 32Si, among others

The presentations and discussions held during the AGM have shown that fallout radionuclides together with 7Be and 2iopfc ^ important tools for erosion studies, especially when the usee yar d combined with conventional methods. Soil erosio strongls ni y linkeo dt soil degradatio d soian nl productivity losses which represen a seriout s threa n mani t y countries. This fact justified the participation in the AGM of representatives from the Joint FAO/IAEA Divisio fro d Lane nWateman d th dan r Development Division, FAO, Romeo wh , presented their representative programmes on soil erosion studies.

The same above-mentioned radionuclides allow, in many cases, the determination of sedimentation rate n lakesi s , estuarie d man-madan s e reservoir providd an s e extensive informatio dynamice th n n o origin d san sedimentsf so .

Many of the techniques discussed in the AGM can also provide valuable information for ongoine manth f yo g IAEA's technical co-operation projects dealing with sedimentological studies. In order to facilitate the transfer of this technology to developing Member States, the establishment by the IAEA of a laboratory specialized in sampling and measurement 137 techniques of the involved radionuclides (specifically Cs, 239-240pu? 2iopb and 7ge) h^ been considered. This report provides the summary statements prepared by the working groups members along with their recommendations. Also included are several background papers that were prepare supporo t d e activitie th te Advisor th f o s y Group. This report strongly encourages the promotion of the application of nuclear techniques for studying and measuring the effects of the erosion/sedimentation cycle on the landscape.

General recommendation summarizee sar followss da :

1. The application and use of nuclear techniques to measure soil erosion and sediment deposition rate d patterne landscapth an s n o s e e promotedneedb o t s . Such applications woul especialle db y usefu developinn i l g countries where ther s ofteei n limited datinformatiod aan soin no l erosio sedimend nan t deposition.

2. The application of environmental radionuclides for integrated studies of the erosion/sedimentation cycl drainagn ei e basin meana s sa understandinf so g erosion and sediment depositio theid nan r landscapeeffecte th n o s , soil quality, water quality, and water availability should be increased in the future.

. 3 Integrated studie f landscapso e shoul encouragee db studiey an soin n di so l erosion and sediment deposition. 2. WORKING GROUPS CONCLUSIONS AND RECOMMENDATIONS bomb-testinf o e Us 2.1 g radionuclides (137Cs, E9-uopu), 2Id °P soan bn i U e erosio^ n studies

Summary statement prepared by the working group members on measuring erosion rates using radionuclides

Group Members: D.E. Walling, G. Elliott, H. Dörr and J.C. Ritchie

137Caesiu s beemha n used extensively ovee pas5 yearth r2 t n researci s d an h applications to measure soil erosion. These studies have shown that the 137Cs technique for measuring erosion is often the only way to get actual measurements of soil loss and redeposition in the field. Studies suggest that the errors associated with the 137Cs technique may be less than those associated with current techniques used by soil scientists and geomorphologists to study erosion. If we understand the limitations and design studies to minimiz e effecteth thesf o s e limitation measurementn so s then measurin concentratioe gth n of 137Cs across the landscape can provide accurate and valuable information on erosion and soil degradation suchs A . , researc applicationd han s should continu developmene th n eo d an t application of the technique in an effort to better understand erosion on the changing landscape.

Status of 137Caesium erosion estimation technique:

Reference sites: 137Caesiu mknows i globalle b o nt y distribute mannea n di r consistent with known production. A large number of measurements allow us to approach factors which produce local variability. Criteria for reference sites are well established.

Sampling: Criteri r slopafo e samplin e acceptedgar . Large diameter cores extending beyond known (measured) distributio recommendede nar . studSiza f eo y unio t acceptes i tp u e b o dt . 10Largeha 0 e studieb r unity dma s from extrapolatio d froan nm representative Land Mapping Units.

Interpretations: Not necessary for some practical applications, for example, relative management effects, productivity effects, before and after studies. Results represent long-term averages. Regionally limited estimates of soil loss is possible which may be improved by comparison at several types of sites where actual soil loss has been measured. Time available for studies range higd shalf-lives3 froan h o t w inventoriem1 lo r fo , s respectively.

Application: Numerous example available sar publishee th n ei d literature fro l continentmal s except Antarctic. Recommendations for 137Caesium based erosion studies

1. Collate existing data of 137Cs input data on a global scale, critically review results, fill knowledge gaps.

2. Determine examples of input and slope variability by both total content and distribution over a range of erodability classifications.

3. Review current Cs interpretation models: represent most likely response I37 envelope.

. 4 Determin consistence eth f differentyo modelr fo sC s interpretation using rainfall simulatio profile B d en an change wels sa wit s 137a l h measured soil loss 7 (plots, farm fields, etc.).

5. Define variability of the adsorption and transport processes .

6. Measure a sufficient number of samples to adequately allow calculation of practical variabilit addition yi experimentao nt l errors permio t , t geostatistical processing of the results (other non-parametric statistics also may be appropriate).

7. Combine Cs and Pu isotopes measurement for both future technique 137 development and to determine the degree of dependence of movement of the isotopes in a soil profile.

8. Investigate wind erosion estimates by Be and Pb sequential concentration. 7 210 9. Extend point studies to the drainage basin by integrating erosion and sedimentation studies especially repeating the label measurements of sediment transpor partitioy tb n into particle size fractions.

2.2 Use of bomb-testing radionuclides ( Cs, 239-240pu)? and 2iopb in sedimentation 137 studies

Summary statement prepared by the working group members on dating sediment deposits using radionuclides

Group Members: D.N. Edgington, V. Dubinchuk, F. Oldfield, J.C. Ritchie, and J.M. Smith.

Radionuclides, hi particular Cs, Pb and to a lesser extent 239-240p 238p have 137 210 u? U; prove vere b yno t valuabl studien ei sedimentatiof so watei nh r bodie diverss sa oceane th s ea , large and small lakes, estuaries, reservoirs and flood plains. Measurement of radionuclides in sediment d associatean s d catchments have provided critical informatio n sedimentatioo n n rates, bioturbation, horizontal movemen sedimentsf o t , resuspension rates residencd an , e times of particle associated san d contaminants (including radionuclides themselvese wateth n )i d ran associated catchment areas. applicatioe Th radionuclidef no stude th sedimenf yo so t t geochronologie subjecs i o t a variet physicalf yo , chemica biologicad lan l constraints. Geochronologies determined using a particular radioactive tracer must be validated using an independent technique which may include another radionuclid non-radioactivea r eo , time-stratigraphic marker.

Radio-geochronological techniques involve either the use of a radionuclide that has a specifically known time dependence for its introduction into the ecosystem (e.g. Cs and ~ 137 239 continuousPua r )o , relatively constant flux fro atmosphere mth e (e.g. Pb,e th Si)n I . 240 210 32 first case, the fallout isotopes provide a time-stratigraphic marker that corresponds either to the maximum deposit of fallout in 1963 or to the threshold for initial inputs in 1952-1954 which under certain constraint providn sca maximuea m estimat average th f eo e sedimentation rate. In the second case, Pb provides a continuous or running measure of sedimentation 210 ageratd ean .

Whil relativels i t ei y easchead yan measuro pt e these radionuclide sedimentse th n si , the interpretation of the profiles is not simple and requires the application of mathematical models which, in turn, are based on specific sets of assumptions. The physical, chemical and biological constraints mentioned above, complicate this model analysis. Som f theso e e constraints are (a) non-steady-state erosion from the catchment which affects the essential assumptions of a constant flux for the 210Pb profile and may effect the depth below the sediment/water interfac maximue th r efo falloumn i t activity internae th ) (b ; l disturbancf eo the sediments immediately below the sediment/water interface by biological or physical mixing (commonly referred to as bioturbation); (c) sediment focussing - the horizontal movement of sediment and contaminants as a result of resuspension (redeposition processes); an) couplin(d d f surfaco g e disturbanc y stormb e s translated into sediment scarrind an g redistribution that can dramatically affect the sediment deposition record.

Recommendation usinn so g radionuclide sedimentation si n studies.

e decisioTh o 1initiallt n. y employ radionuclide technique o construct s a t geochronolog f sedimenyo t depositio environmentw ne n ni s shoul basee db d attachee onth d decision tree using available environmenta catchmend an l t data (See Figur. e1)

2. Wherever possible the environmental data should be included in a computer based Geographic Information System (GIS) and related to aerial and satellite imagery.

3. For evaluation of new environments or catchment systems in developing countries, the establishment of a data base should be encouraged for input into the decision tree (See recommendation 1).

4. Perform a literature survey of the applications of radionuclides to the study of sediment depositio aquatin i c systems, particularl thosr yfo e studies available non-journae onlth n yi l literature.

5. Develo traininpa g manual (and course plannine usee th b ) n thadi n d gca an t executio sedimentatiof no n studie aquatin si c systems. This would include:

10 DECISION TREE PROCESS FOR DETERMINING THE FEASIBILITY OF USING RADIONUCL1DE STUDO ST Y SEDIMENTATION

WHAT B THE DETERMINES THE ABSOLUTE LATITUDE OF THE MAXIMUM ATMOSPHERIC CONTRIBUTION CATCHMENT OF RADIONUCUDE

E TH S I D OL W HO DETERMINES WHAT FLUX/SIGNAL WATERBODY IS POSSIBLE FROM Ct-13 Pb-21R 7O 0

WATER/LAND «1.0 THEN PROBLEM WTTH VARIABLE FLUXES FROM CATCHMENT WHAT IS THE RELATIVE O(tOXatm• ) O(c»tcl>)• ) ARE WATEF AO LANO RT D WHERE O - FLUX OF RADIONUCLIDE OCotch DEPENDENS )I N TO GEOMORPHOLOGY. HYDROLOGY, SOIL. AND LAND USE

WHAT TYPF EO FREQUENCYW LO f I , HIGH MAXIMUM HYDROLOG1CAL EVENTS EVENTS DOMINATE WILL LEAD OCCUR TO CATCHMENT DOMINATED INPUT

ADSORPTION OF Cs-137 HIGHLY SOI| WHAE LTH TYPS TI E DEPENDENT ON SOIL TYPE "MINEROLOGY --PARTICLE SIZE

, AKALINITYpH AFFECm ,Do T WHAT IS THE WATER Kd, SIGNAL/NOISE RATIO TRAPPING EFFICIENCY OF SEDIMENT QUALITY

WHA WATETS I R AFFECTS TRAPPING RESIDENCE TIME EFFICIENC PARTICLEF YO D SAN RADIONUCLIDES

DECISION TIME

BASED ON INFORMATION FROM DECISION TREE, DECISION CAN BE PROBABILITE MADTH N EO SUCCESF YO S STUDA F O Y USING RADIONUCLID STUDO ET Y SEDIMENT DEPOSITION 1. IS THIS A SUITABLE CATCHMENT AREA FOR STUDY? 2. WHAT IS THE LIKELYHOOD OF SUCCESS? 3. WHAT WILL BE THE PROBLEMS? . WHA4 T RADIONUCLIDES SHOUL MEASUREDE DB '

AFTER DECISION THAT WATER BODY IS ACCEPTABLE THEN THER STEO EPTW WILPROCEEOURA E LB DATT R GE A FO O ET ANALYSE REACO T D H SCONCLUSIONAN S

FIRST STEP SECOND STEP SEDIMENT SURVEY DATA ANALYSIS

-2> SEDIMENT DISTRIBUTION SAMPLE ANALYSES h-5> SEDIMENT DEPTHS MODEL SELECTION

. SEDIMENU> T TYPE MODEL ASSUMPTIONS

l_e> POROSITY DATA COMPILATION SEDIMENT SAMPLING CONCLUSIONS

Figure 1

11 ) a decision tree b) basic information on techniques c) sampling techniques ) d analytical techniques/equipment e) modelling approaches and assumptions f) reporting requirements g) associated measurements needed (i.e particle sizes, carbon, etc.) ) h preliminary site assessments i) potential pitfalls and how to avoid them

6) Recognize that the assignment of a geochronology to a sediment radionuclide profile is no better than the model and assumptions used. It is critical that the result f thio s s exercise mus e validateb t n independena y db t method (two different radionuclide chronologies, other dating techniques).

7) Since it may not be always possible to obtain this independent validation by an independent method, a system of reporting geochronological data that recognize e th distinctios n between validate d nonvalidatean d d geochronologies, must be developed

210r PFo b 8geochronologies) e analysi th e ,profil th f o se doe t constitutno s ea direct measurement of the sedimentation rate, and the results must be validated independenbn ya t technique.

9) 7Be and 32Si measurements are of limited value in sedimentation studies. The 137Cs and 210Pb measurements are sufficient.

10) Since 239-240pu v^ll provide markers for many millennium to come and measurement thesf so e radionuclides provid verea y favourable signa noiso t l e ratio, researchers should be encouraged to include these in the construction of environmental data set sspecificall- relation yi integrateo nt d fluxesoile th sn si catchmente ofth .

11) Encourage studie establiso t s networha k with appropriate site measuro t s e atmospheric deposition of contaminants (wet and dry) including 210Pb and 7Be.

12) Evaluate the use of other non-radioactive tracers such as pollen and ô C in areas wher e eproblemb thery ma f evalidatio o s f o nr P(o bCs ) 210 137 geochronologies.

13) One or two demonstration catchments to assess the use of radionuclide techniques to study erosion and transport and sedimentation in the receiving water body shoul selectede db .

12 decisioe Statementh f o ne treeus n to .

The decision tree (Figure 1) is a technique to allow a decision to be made on the feasibility for success of the application of radionuclides to the study of sediment deposition befor sampley ean takene sar .

Simple questions are asked which can be answered based on existing or readily available datainstancer Fo . ;

1. latitude Whastude th th s i tf y eo siteknoe W ?wmove w tha s ea t froe mth north temperate zone that there wil lowee b l r fallout levelse . ar Thuse w f i , settin aristudn a a dp gn u yi are a nea equatoe rth mighe w r t expect problems fallouw lo signa w o tt lo ratenoise o lt d du san e level. watee th constructes s ri bodyd wa t ol i f I w ? dHo after . 1962 5 then there wile b l no Cs peak to measure. Is it old enough for Pb to have reached an 137 210 acceptable level of equilibrium?

By answering this series of simple questions a decision maker will be able to determine the likelihood of success or failure of using radionuclides to measure sediment deposition. The technique could be used to eliminate studies where there was initially little probability of success.

3 2 Applicatio f long-liveno d cosmogenic radionuclide studien i s f erosioo s d nan aggradation

Summary statement prepare e workinth y b d g group member long-liven o s d cosmogenic radionuclides in studies of erosion and aggradation

Group MembersV.Md .an l NijampurkaLa . :D r

A numbe f nucleao r r methods base n cosmogenio d c nuclides producee th n i d atmosphere and in-situ in diverse surfacial materials are applicable for studies of erosion and aggradation. Both these sources of nuclides provide natural tracers for quantifying erosion and aggradation processes.

. A Atmospheric Nuclides

The nuclides 10Be (half-life=1. 5(half-life=573C 14 my), 0 years) d 32san ,i (half- life mos e years0 ^th 5 te promisin)ar thesr gfo e applications.

Extensive profiles of Be reported in the literature in global soils clearly show that 10 this nuclide provide usefun sa l snapsho dominatinf to g erosional/aggradation process.

The radionuclide 14C is an useful indicator of local transport of organic carbon from the soils.

The bomb-I4C can be used to quantify any recent dramatic changes in soil dynamics.

13 There have been limited measurements of 32Si so far, but the fact that this nuclide is quickly adsorbed in the soils (on clay surfaces) by exchange, most of the 32Si inventory in clayey soils would be expected to be in the top few meters, and at greater depths for sandy- clayey soils. Consequently, measurements of its integrated column inventories are expected indicative b o t meaf eo n soil erosion rates durin pase gth t 200-250 years.

. B In-situ cosmogenic radionuclides

Several in-situ cosmogenic nuclides, 10Be (half-life=1.5 my), 26A1 (half-life=0.7 years) (half-life=573C 14 , 0 years) 39d Aan ,r (half-life=270 years currentle ar ) y being studied investigato t wida e e variet f geomorphiyo c processes. These studies havbecomw no e e possible primarily because of the development of accelerator mass-spectrometry (AMS) method which allows measurement of about 106 atoms in each of the cases mentioned above (excep 39 r principae Ar)tfo Th . l advantag in-situe th f eo cosmogenic metho thas di t since eth nuclide source function e knownar s t i allow, a quantitativs e e erosiostudth f d o y an n aggradation rates, irrespectiv chemicay an f biologicaed o an l l reactions occurrin uppee gth r layers validite erosion/aggradatioe Th th . f yo n checkee modeb n r ca o lanalysey db o tw f so more nuclide soil/sedimena n si t horizon.

The in-situ cosmogeni mose th f ct o quantitativmetho e on s di e methods availablo es thesr fafo r e studies, however doet ,i s require specialize sophisticated dan d methods whice har to date being employed only in developed countries. But these techniques are becoming increasingly availabl largea o et r numbe laboratorief ro ovel sworldal e rth .

Recommendations

recommendes i t I d that:

1. in-situ nuclides be used to provide absolute erosion/aggradation rates in horizons studies using other techniques (e.g. 137Cs), to permit an intercalibration between studies

2. attempt made b s provido et facilitie S know-hoe e developinAM eth th e o st th d wan g nations to earn out these measurements.

2.4 Tracer techniques and nuclear gauges

Summary statement prepared by the working group members on artificial tracers, tracer techniques and nuclear gauges

Group Members: J.V. Bandeir O.Sd aan . Tazioli

Potential

Artificial tracers technique nuclead an s r gauge usee ar ssolv o dt e many engineering and environmental problems.

14 A major fiel applicatiof do f artificiano l tracer stude th sedimenf ys o si t dynamicr sfo small-scale problems, but there is also a possibility for application to relatively larger scale problems.

A unique characteristic of tracer methodology is the ability to integrate the response of sedimen variouo t s flow conditions occurring over finite time.

The tracer's spatial distribution may be interpreted directly to provide quantitative or semi-quantitative information which canno obtainee b t othey db r methods. They also allow the evaluation of parameters necessary to calibrate mathematical models related to sediment transport.

In marine environments, radioactive tracers technique vere ar s y usefu r selectinfo l g dumping sites for dredged material, providing information on the behaviour of suspended sediments, determinin e extength f depositionao t l area determinind an s e subsequength t behaviou f depositeo r d sediment. e alsb The on applieyca studo dt e naturayth l bottom sediment transport.

Another potential applicatio f traceo n r technique e labellinth a smals i sf o gl representative area of a catchment (e.g. gullies) with artificial tracers in order to determine the erosion rate of such areas.

In case of small clay catchments (10-200 ha), the erosion rates may be evaluated by measuring suspended sediments using nuclear gauges. They can give a continuous record of suspended sediment concentrations, allowing the calculation of total suspended load.

Another possibility to evaluate erosion rate is by determining the mass of the sediment deposited in a reservoir. The vertical profile of the sediment bulk density may be measured with gamma-gamm neutrod aan n probes.

Nuclear gauges may be used to control the density of deposited sediments in navigation channels, turning basin berthind san g area harboursf so horizoe th d orden i ,nad o rt of 1.2 g/cm3 to navigation depth. A possible application of nuclear gauges is for controlling the dense suspensions created near the bottom just after the dumping of dredged material.

Another application is for measuring the density profiles in the well of trailing suction hopper dredger optimizo st dredgine eth g time with overflow.

Limitations

Most limitations on the use of nuclear techniques are related to safety concerns about radioactivity by specialists involved in sedimentological studies and due to strict regulations and laws of some countries for the use of radioactive material.

With regards to the application of nuclear gauges there are fewer difficulties for permanent field installations. These monitoring station e normallar s y establishen i d inaccessibl e equippeear sited an s d with radioactivf o e i sourcemC 0 s 10 betwee d an 1 n

15 activity. Another limitation on the use of nuclear gauges is represented by the threshold (must be greater tha mg/1 nsedimen1 e th f )o t concentration.

The application of tracer techniques and nuclear gauges require specialized people. At presene th t time technologe sth s sufficientlyi y develope appliee b wid a o dt n di e rangf eo field conditions. Concerning tracer techniques in bottom sediment studies, an aspect that shoul improvee db determinatioe th s di thicknese th transporf e no th f so t layer.

16 PAPERS PRESENTE MEETINE TH T DA G

17 FAO'S PROGRAMME ON SOIL EROSION

D.W. SANDERS Soil Resources, Management and Conservation Service, Lan Wated dan r Development Division, FAO, Rome, Italy

Abstract

The present situation of land degradation in global basis and its negative impacts on soil fertility are presented. The activities undetaken by FAO on erosion control are described. Some recent trends in soil and water conservation are also included.

Background

The problems of land degradation, particularly soil erosion, are not new. This was recognised by the founders of the Food and Agriculture Organization of the United Nations (FAO) and Article I of the Constitution reads, "The Organization shall promote and where appropriate shall recommend national and international action with respect to the conservation naturalof resources adoptionthe and improvedof methods agriculturalof production". Thus, since the Organization was founded in 1945, FAO has been active in promoting soil conservation.

Ove yeare th r s thi establishmene s th involvemen o t d le larga f s o et ha t numbef o r programmes and projects through which FAO has been able to assist its member countries to develop soil conservation policies, launch land conservatio rehabilitatiod nan n schemed san train local staff.

But in spite of the efforts of FAO and other organisations, soil conservation has received relativel priorit w plane lo yth f moso n syi t countries until lately. Priorits wa y generally give programmeo nt mora f so e eye-catching natur thoso t r eo e which promiseo dt produce quick economic returnmonee th r sfo y invested. Generally feelin a ther s ewa g that there was plenty of land available and that erosion was not such a serious problem.

This attitude has been changing since the late 1970s and there is now far more awareness of the problem of soil degradation and interest in soil conservation. (Sanders 1988). There are a number of reasons for this change and they include:

• Soil erosion, and other forms of land degradation, are now so far advanced in many countries that their effects are obvious even to the casual, untrained observer.

• Population numbers have been growing rapidly in most developing countries and this is resulting in an acute shortage of land in many countries.

• damMane th f sy1960o e buil 1970sth d n si tan Mangl,e sucth Tarbells hd a aan a dams Paldstann i siltine ar , mucp gu h more quickly tha nhige expecteth ho t rate e f sdo du erosion in the catchment areas.

19 • The terrible effects of the droughts in Ethiopia and other African countries over the last two decades have now been closely linked with soil degradation. world-wide Th • e interes publicitd an t y give environmentao nt l matters ove lase 0 rth 1 t years0 2 o t , particularly sinc publishine eth 'Brundtlane th f go d Commission report 1 and, more recentl UNCEe yth D Conferenc Janeiroe d o Ri ,profouna n havi ed eha d e publi th morw effect d largno a ce an s i teintereste e protectioth e n th i d f o n environment than ever before.

However, turning this interest into effective programmes has not proved to be an easy taskr example Fo t know. no stil e o w n,d l witdegrey han f certainlyeo mucw ho , h lans di affecte soiy db l erosion degree th , whico e t rat affectee s i whict th t eh a i d erosioe dan hth s ni progressing.

To compound this problem, many countries are now running out of new land which is suitable for agricultural production. Farmers are turning more and more to the steeper slopes, poorer soil othed san r areas t onlwhicno ye difficulhar alse ar ofar o t t tver mbu y prono et erosion. Less land can be left idle so fallow periods are being shortening with a resulting declin soin ei l fertilitincreasn a d yan erosion n ei .

The Exten Lanf to d Degradation

The most recent and reliable global assessment of land degradation is the GLASOD (Global Assessmen f Soio t l Degradation) study, undertake e Internationath y b n l Soil Reference and Information Centre (ISRIC) in collaboration with UNEP, FAO and a number of other institutions e resultin Th e Statuth . f gHuman-induce o sf o "Worl p Ma d d Soil Degradation s publishewa " d wit explanatorn ha y not n 199i e 0 (ISRIC 1990). This wa s followe estimation a areay e db th f s o naffecte differene th y db t form degradationf o s 1992n i , . (ISRIC 1992)

Although this GLASOD study does give us, for the first time, a reasonable global pictur extene th lanf f eo o t d degradation stils i t li , onl ygeneraa rathed an l r crude assessment and the figures should only be seen as an indication of the extent and seriousness of the problem.

A summary of the results of the GLASOD study are reproduced in Table I below.

The GLASOD study indicates that water erosion is by far the most important type of soil degradation affecting abou e totath t lf 1,09o are % a4 56 affectemillio r o humany a b ndh - induced soil degradation. Wind erosion affecte sth abou f millio8 o r abou54 o t% a n38 h t degraded terrain. Other form lanf so d degradation include chemical soil deterioration covering about 239 million ha or 12 % of the area, while physical soil deterioration occupies a-round 83 million ha or 4% of the affected area. (It should be noted that some areas are affected by two or more forms of land degradation.) Other important forms of degradation mapped include salinization, which affects 76 million ha and soils affected by pollution which cover about 22 million ha. (ISRIC 1992)

20 Table I. Major terrain divisions of GLASOD map (in million ha.)

Non-used Stable "Other terrain" Human-induced Total land waterland land (non-degrade soiy db l degradation surface human activities) Africa 732 441 1299 494 2966 Asia 485 1426 1597 748 4256 South America 28 368 1 129 243 1786 Central America 53 27 163 63 306 North America 75 1 043 672 95 1885 Europe 1 20 710 219 950 Australia 95 250 434 103 882 Total 1469 3575 6005 1964 13013 Source: GLASOD - SOTER Newsletter, ISRIC, 1992.

FAO's Activities in Erosion Control

FAO has responded to the changing and challenging situation in a number of ways. One important step was to produce the World Soil Charter (FAO 1982). This short document, whic s unanimouslhwa ConferencO yFA adoptee th n 1981 i ey db , outline a numbes f o r principle guidelined san s which f followedi , , should allo country wan safelo yt y develos pit land resources and contend with the problems of land degradation.

As a follow-up to the adoption of the World Soil Charter, FAO has intensified its work fiele soif th do n li conservation. Efforts have been mad increaso et e awarenes subjece th f so - t t peoplt onlle no o yt e know that ther serioua s ei s proble t alsm inforbu o t m them that land degradation can be prevented and controlled. To this end, a number of publications and filmstrips have been produce subjece th wideld n do an t y distributed while, when requested, visits have been mad countrieo et asseso st s soil erosion problem adviso t d solutionsn eso an .

As already mentioned, comparatively littl bees eha n known until recently aboue th t extent, severity and rate of land degradation on a global scale. FAO has played a leading role e worith n k thas beeha tn don o datt e n developini e a gtestin gnumbea f possiblo r e methodologie quantifd an p yma soio st l erosion numbe.a Thio t d preliminarsf ro le wor s kha y regiona -globad lan l assessment contributed san recene th do t t GLASOD study.

In early years assistance to individual countries centred on field projects. Typically, these projects were concentrated on a particular area - usually a badly eroded watershed - and various conservation practices were tested and developed. These projects were also used as training ground nationar sfo l staffgenerae Th . l idea behind these project thas swa t they would act as demonstrations of what could be done and establish a national cadre of trained and experienced officials s believewa t I .d that once FAO's involvemen overs wa t , after perhaps

21 five years, the government organisations involved would be convinced of the value of what had been done and, with the trained staff and equipment left behind by the project, the work woul continuee db expanded dan otheo dt r areas.

Unfortunately, in practice this seldom happened. The technologies tested and demonstrated were usually base thosn do efarmg use bi developen sn i d o d countrie werd san e not appropriate to the physical, social or economic conditions of developing countries, while local government institutions seldom had the necessary budgetary resources to even maintain wha beed ha tn done t alonle , e expan worke mort dth Bu .e importantly, ther seldos ewa mn a understanding at senior government level of the importance of what had to be done and little it any commitment to long-term conservation. Unfortunately, soil erosion cannot be overcome through sporadic, short-term efforts. It requires a long-term political commitment supported by appropriate policies, strategies and programmes.

In vie thisf wo , FAO's approac s changehha mord dan e emphasi beinw no g s splacei d on helping government asseso st extene sth f theio t r land degradation, develo requiree pth d policie d approachean s d thean sn formulat e type th ef programmeo s se b whic n ca h systematically implemente contendo t d wit probleme hth . Greater attentio beins ni ge paith o dt socio-economic aspects and more effort is being place on the closer involvement of the land users themselve plannine th n si implementatiod gan schemesf no recenA . t exampl thif eo s si the FAO initiative, "The International Scheme for the Conservation and Rehabilitation of African Lands". This Scheme was launched hi 1990 with the purpose of providing African Governments with a framework through which they could develop national land conservation and rehabilitation programmes which would be tailored to their own needs but which also provided technical assistance agencies, funding institutions, donors and NGO's a part to play in the planning and implementation of what is required. This scheme is now in its early stages of implementatio ninn i e countries.

Another initiativ s bee ha eo helt n p develop formal national soils policiesn I . collaboration with UNEP, national soils policies have been completed for Syria and Uganda and are nearing completion for Indonesia and Jamaica.

FAO produces technical publications through which the latest ideas, techniques and approache watesoid o st an l r conservatio promotede nar . Besides this Organisatioe ,th n acts sa a focal poin r governmentsfo t , institution individuald an s s seeking informatio erosion o n n contro direcd lan t enquirie thoso st e places wher bese eth t experienc advicd ean available e ear .

t itselFAno researca Ofs i h organisation although stafs it , f attemp keeo t p abreasf o t the most recent developments mais It . n rol researcn ei identifo t s hi y those field whicn i s h research is needed, encourage and assist the appropriate institutions to take up the necessary research and then help to disseminate the results. In short, FAO's role in research is to act as a catalyst. This rolinvolves sucn ei ha hO programmedFA developins sa g network researcr sfo h

22 into the effects of erosion on soil productivity, conservation tillage practices and conservation farming system r small-scalsfo e farmers subjece Th .f researc o t returnes hi lateo dt thin i r s paper.

Recent Trend WateSoin d si lan r Conservation

Soil conservation, as we know it today, only goes back about sixty years. - It has evolved with the application of science to the problems of land degradation brought about by rapidly growing populations and the introduction of new forms of land use and management (Sanders 1992).

Due to the initiative of the great Hugh Hammond Bennett, the first large-scale, modem soil conservatio e mid-1930nth programmn i A o combat s s launcheUS e e wa eth th t n i d problem e "Dusth f o st Bowl" e creatio th e presen. th o t y USDThif no d da tle s A Soil Conservation Service. Soil erosion was becoming a serious problem hi other parts of the world at this time and other large-scale programmes were started soon after in several African countrie Australiad san .

With their impressive 1930e wor theith d n ksi an r well organised conservation service, the Americans soon becam recognisee eth d leader thin si s fielconservatiod dan n programmes in most parts of the world were based on the technology developed in the United States. Most of this technolog developes ywa r large-scaledfo , mechanised farmin depended gan d mainly upon mechanical erosion control measures - works such as artificial waterways, graded contour banks, diversion system othed san r engineering works which reduc lengte e eth th f ho slope and slow down the movement of runoff water. Methods were developed for estimating the amoun f soio t l loslikele b t o yt unde r different system f managemeno s extensiod an t n programmes were introduced to alert farmers to the risks of erosion and the benefits of soil conservation.

The general approach to soil conservation changed little from the 1930s until the early 1980s. Since then considerable changes have taken place.

Changes have come about wit realisatioe hth n thahuge spitn th i t f ee o amount f o s money that were being, spent on soil conservation - Napier (1988) claims that the USA alone has spent $18 billion since the 1930s and is-now spending about $1 billion a year on soil conservatio nsoi- l erosio increasins ni g rather than decreasing. Ther numbea e ear reasonf ro s for this and they include: a) Increased demands being placed upo lande nth :

e casI nth f developin eo g countries, increased population numbers have meant that broughe b moro t d te intha lan s od ha productio lane th d d alreadnan production yi s nha to be used more intensively. Unfortunately, most of the best land is already in use so that mor mord ean e marginal, erosion prone lan beins di g use agriculturr dfo e while eth more intense bettee useth f -ro lan s oftedi n resultin degradationn gi developen I . d countries, modem, highly mechanised farming systems, combine somn di e cases with

23 inappropriate agricultural policies, have led to large tracts of land being misused and degraded. b) The technology has frequently proved to be inappropriate:

Soil erosio bees nha n seephysicaa s na l proble techniquee th d man s developes it r dfo control have been largely base engineerinn do g works which decrease runof soid lan f movemen reduciny b t e lengt gth d angl y an slowinhf slopeb o e d an sg dowe nth movemen f watero t . While suc he technicall b work y ma s y effective, they have generally prove expensive b o dt instalo et timd an el consumin costld gan maintaino yt . These disadvantages would be acceptable if land users perceived them to be worthwhile but, unfortunately, these physical works usuallt providno o yd e adequate financial returns to make them attractive to farmers. There are exceptions, for example where terracing make possiblt si irrigato et groo t r wehigo a h value resultcropa s A ., land users have been reluctant to accept much of the soil conservation technology that has been advocated. Furthermore, many large and expensive soil conservation projects have failed because farmers have not maintained the-works that have been installed.

Wide-scale and effective erosion control can only be achieved if the land users themselves- can see some direct benefit from practising soil conservation measures. It is now being realised that this will only come about if the land users a-re offered techniques and practices which not only preven controd an t l erosio whict nbu h also lea increaseo dt d production, more assured. yields, lower input costs, lower labour requirements, or some other direct and obvious short- term benefit.

The implications of this have been a move away from mechanical erosion control measuree promotioth d an sf "biologicalo n conservation practices e mosTh t. effective 1 practica protectinf o y lwa soie gth l from erosio ensuro t s ni e coverethas i t i t d with either live or dead vegetation. As can be seen from the diagram below, even a partial cover of vegetation has a profound effect on erosion and runoff.

Because of this, soil conservationists are now concentrating on developing and adapting system f lan whicse o dus h will provide vegetative protectio mucs a soie r hth fo l o nt of the year as possible. This has resulted in the promotion of relay cropping, minimum tillage systems, mixed cropping, agroforestry and any other system of land use which is likely to be profitable t easilfi , y into existing farming system alsd soan provide good ground l coveal r rfo or most the year. This change has led to a renewed interest in traditional farming systems, many of which were very conservation effective but which have gone out of use because of increased pressur e lanchangind th an dn o e g economi sociad can l conditions e.g. shifting cultivationpossible b y modifma o e t t I adapd . yan t som thesf e o system d eol preseno st y da t conditions.

Research into the Effects of Erosion on Soil Productivity

Just as changes were needed in the approach to conservation, changes were also needed in soil erosion research.

24 Figure 1 American soil scientists The effects of low-level cover in reducing splash and engineers have led the way in erosion and rainfall erosivity. (Source: Land researc embarkeA h US sinc e eth d Husbandry - A Framework for Soil and Water upon its soil conservation Conservation by Shaxson et al.) programm e 1930 th thei d n ei san r early wors continueha k o t d . Effeca f low-leveo t l soil cove splasn o r h erosion dominate soil erosion research. Their- wor s concentrateha k n o d the assessment of soil loss in terms Overhead vie f randomlwo y distributed cover. For best effects, cover should be on or very of mass of soil lost per unit area, nea soie th rl surface evenls a d yan , spread as possible. e.g. tonnes of soil lost per acre. Of particular importance th s wa e development of the Universal Soil Loss Equation by Wischmeier and 60% 100% Smith (1978). This has subsequently served as the starting point for research into soil erosion on experimental stations all over the world strono S .this gha s influence

_ .. . I been that similar work, on similar 0 10 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 l al e b foun n o plotsn dca , ! Percentage of rainfall energy intercepted by low-level cover to the soil continents. This has had man b. Effec; of cover by plants on rainfall erosivity benefits. It has allowed the easy • • i i t i exchange of information between

L research workers from all over the Erosivity i of rainöroos 1 world and has led to a very good 1 dimimshec 1 1 ; t : 1 oy cover 1 ^ l understanding of the mechanics of i : = !i i*7 . erosion. It has also enabled us to ^ • s~~ Soil exposed1 ' &* II 1 .1' JÇr . :^ f. ^ ^i=m .•^ i Î fe to erosive ^r" _'i r' predict with reasonable accuracy rainfall —^ the rat t whica e h different soils c r; i_ cn c cn CD a % 0 ± % 40 80% = will erode under different systems Effect 01 cover by plants on rainfall erosivity of management.

othee Onth r hand generae ,th l adherenc rathea o et r narrow lin researcf eo mano s y yhb people appear havo t s e stifle procedurew dne initiativw fe sd havean e been developed dan ther bees eha n Little innovative wor thin ki s field until recently.

The measurement of soil erosion in terms of soil lost per unit area is important when we have to consider the off-site effects of erosion. For instance, it is important if we are to calculate how quickly a new dam will fill with silt or the effects of erosion on water quality. This typ measuremenf eo erosiof to therefors nha e bee particulaf no wherA rUS ebenefi e th n i t recent research has shown that the productivity of most of the land has not been seriously reduce erosioy db n (Napier othe e 1990)th n r handO . , research conducte Conservatioe th y db n Foundation shows that off-site damag considerables ei , amountin leso n s o gthat billio6 $ t r npe year. Under these circumstances the USA research workers have been right in following this lin researchf eo .

25 Whil on-site eth e importane effectb t USA e erosiof no th o s situatioe y n i t,th nma s ni different in most other parts of the world. For instance, many tropical soils are very shallow and hold a large proportion of their nutrients in their top soil which may only be a few centimetres thick. With these soils losmillimetree w onlf th ,so fe ytonnea w fe soilf a so r o , per ha, can rapidly lead to a marked reduction in their productivity. Under these conditions the off-site effect f erosioo s n become secondar on-site th o y t eneede effectth f researcd so an s h change. Unless silt is creating some down stream damage, such as filling up a new dam, the actual degree and rate of erosion may be of little importance. Certainly, farmers are seldom impressed or influenced when told how much soil is being lost from their land - their interest tie whan si lane producn th t dca whethed ean r this productivit beins yi g reduce erosiony db . Similarly, economists, banker otherd o allocatan s wh s e fund r lanfo sd conservatiod an n reclamation-programmes, find rates of erosion expressed in tonnes of soil lost per ha as meaningless - they are interested in what this loss represents in money terms how the erosion has affected the ability of the soil to produce!

In view of this, FAO initiated a programme in 1984 to encourage research into the effects of erosion on soil productivity.

Networe Th Erosion-inducen ko d Los Soin si l Productivity

Soil erosion costs mentiones A . d above off-site th , e calculatee effectb n ca s d relatively easil f welyo througe l knowus e hth n techniques which measur volume eth r maseo f soiso l erosion. It is the on-site costs about which far less is known. As Stocking (1985) points out, questione th s tha woule tw d like answered are:

• What factors cause productivity decline when erosion occurs t nutrieni s I ? t loss, nutrient imbalance, reductio n rootini n g volume, los n availabli s e waterholding, capacity or what?

• How does crop yield vary with erosion and with time? Is the problem worsening or have the major farming systems of the tropics reached a stable level of low productivity? soin lCa conservatio • n recou decline pth productivityn ei some ?Ar e techniques more effective that others?

Although these questions were commonly being asked by the early 1980s, very little wor beed kha n don provido et answerse eth vien I publicise. thisf wO o FA , alsface d dth oan t developed a research design which could, in time, provide some of the answers.

Very briefly, the experimental design is based on soil loss and runoff plots. The recommended design plotallow2 1 sr whicsfo permittee har erodo dt e naturall t wite ybu hth rate of erosion controlled by the use of plastic mesh of different gauges; 12 plots which are artificially desurface represeno dt t different degree erosionf so thred ;an e control plots.

Besides the usual collection of data on soil loss and runoff, the design allows for the regular monitorin f soio g l physical properties including particle size, aggregate stability.

26 infiltration rate, soil strength, bulk density, soil structur soid ean l moisture chemicad an ; l properties such as pH, organic matter, N, P, K, Ca, Mg, Na levels, cation exchange capacity, base status, available Al, Bo, Cu, Mn, Zn and Mo. Runoff water is tested for pH, N03-N, NH4-N. P04, K, Na, Ca, Mg, turbidity and sediment concentration. The biological activity of the soil is monitored, climatic data recorded and plant growth measured and recorded. Full details of the experimental design are to be found in the publication "Erosion-induced Loss in Soil Productivity: a Research Design", Consultants' Working Paper No. 2, issued by the Land Wated an r Development Divisio FAOf no .

expectes Ii t d that, afte foua r fivo t r e year cycl f experimentationeo , trials-of this type will provide informatio: non

yielmajoe a r th dfo w r cropHo , • grown unde prevailine rth g condition localitye th f so , o specifina c soil, varies with tim soid elan loss.

• What the relationship is between erosion allowed to occur from natural rainfall and artificial desurfacin thao s g a next t phas f experimentationo e , perhap n farmerso s ' carriee fieldsb usint n dca simpl,ou e gth e metho desurfacingf do .

• What are the causative factors in decline in yield.

A modest starmads thiwa tn eo smid-1980 e worth networn e ki th t s slowlsbu kha y Crown so that it now includes 21 institutes in 19 countries: Botswana, Brazil, Cameroon, Chile, Colombia, China. Ethiopia, Ghana, Indonesia, Kenya, Lesotho, Mozambique, Nigeria, Paraguay, The Philippines, Rwanda, Spain, Tanzania and Thailand. Most of the institutions are only just starting or recently started to gather data so that it will be some time before the result f moso sf thio t s work become available. However ,e institutesomth f o e s have completed four or five years of work and the first full report appeared recently - "Erosion: Its Effects, on Properties and Productivity of Eutric Nitosols in Gununo Area, Southern Ethiopia, and Some Techniques of Its Control' (Tegene 1992). It is anticipated that this, with the other reports that are likely to follow shortly, will give us a far better insight into the effect of soil erosio soin no l productivity.

BIBLIOGRAPHY

1982O . FA World Soil Charter. Foo Agriculturd dan e Organizatio Unitee th f no d Nations. Rome, November, 1982.

Conservatioe Th 1990O . FA Rehabilitatiod nan Africanf no Land Internationan A s- l Scheme. Food and Agricultural Organization of the United Nations. Rome. ARC/90/4 W/2/57OOE/3/2.93/1000.

ISRIC 1990. World Map of the Status of Human-induced Soil Degradation. Global Assessmen Soif o t l Degradation. ISBN 90-6672-042-5.

ISCIC1992 GLASO D- SOTE R Newsletter 353x , Bo . P.O670.5 . J . Jun0A No e 1992. Wageningen, The Netherlands. Napier T.L. 1990. The Evolution of US Soil Conservation Policy: From Voluntary Adoption to Coercion. In Soil Erosion on Agricultural land, Edited by J. Boardman, I.D. Foster and J.A. Dearing. John Wile Sony& s Ltd.

Sanders D.W. 1988. Food and Agriculture Organization Activities in Soil Conservation. In Conservation Farming on Steep Lands. Editors W.C. Moldenhauer and N.W. Hudson. World Associatio f SoiWated no an l r Conservation, Ankeny, Iowa, USA. ISB- N0 935734-19-8.

Sanders D.W. 1992. Soil Conservatio 199n ni Internationan 2A l Perspective Australian I . n Journa Soif Wated o l lan r Conservation. Augus, 3 ,. volno , t. 5 1992. ISSN 1032-2426.

Stockin . 1985M g . Erosion-induced Los n Soii s l Productivity ResearcA : h Design. Consultants' Working Paper No. 2. Soil Resources, Management and Conservation Service, AGL, FAO.

Shaxson T.F., Hudson N.W., Sanders D.W. ,Moldenhaued Roosan . eE r W.C. 1989. Land Husbandry - A Framework for Soil and Water Conservation. World Association of Soil and Water Conservation, Ankeny, Iowa, USA. ISBN 0-935734-20-1.

Wischmeier W.H. and Smith D.D. 1978. Prediction Rainfall Losses - A Guide to Conservation Planning-. USDA Agricultural Handbook no. 537.

Tegene B. 1992. Erosion: Its Effects on Properties and Productivity of Eutric Nitosols in Gununo Area, Southern Ethiopia Somd an , e Technique s ControlIt f o s . Institutf eo Geography, University of Bern, Switzerland. ISBN 3-906290-74-3.

28 THE ROLE OF NUCLEAR TECHNIQUES ÎN SEDIMENTOLOGICAL STUDIES AND SOME APPLICATION LATIN SI N AMERICA

P.E. AUN, J.V. BANDEIRA Brazilian Nuclear Energy Commission, Nuclear Technology Development Centre, Minas Gérais, Brazil

Abstract

technicae Th practicad an l l consideration groua f so p thas beeha t n workine th n i g application of tracer techniques since 1962, without interruptions., in a developing country are presented. Some hints to survive in this environment are included as an introduction, hoping thae usefub t o initiatiny thet l ma y g groups e papeTh . r trie o summarizt s e grouth e p experience in the fields of sediment transport and use of nuclear gauges in sedimentological studies and to present their point of view about the future trends for these techniques.

Some brief considerations abou relationshie th t p between sediment transpore th d an t environmen followee ar t descriptioa y db usee f artificiath so f no l tracer sedimentologyn si , with a strong emphasis on their practical and logistics aspects, including some topics that are never included in technical papers. In sequence, the basic principles of nuclear gauges in relation to sedimentological studies are presented, together with some specific uses and results of these equipments.

Case studie thee sar n briefly presented, stressing agai engineerine nth g information obtained through the application of nuclear techniques.

e lasTh t part discusse e fieldth s s into which nuclear technique e superioar s r o r competitiv conventionao et l technique studien i s s involving sediment included an s s some prospective comments about their future. In particular, some detail is given to the importance of inducing the transference of nuclear techniques to hydraulic institutions and to the important influence thadevelopmene th t mathematicaf o t l model f sedimenso t transport will play in our future.

INTRODUCTION

A Review Paper presented by members of a group that works in a developing country is an uncommon unexpecte n evena d tan d honour. Another surprising aspect is that this group has been working, without interruption, since 1962 in tracer applications, maintaining a minimum staff of 12 specialists. The most important difficulty to surmount in a developing country is to preserve in the group some key-elements in different areas. Several promising groups disappeared or reduced drastically their activities when the specialist3 y r loso 2 t s that exerte tase df pushinth k o g thing . Thison s difficult sometimen yca overcomee sb groupe beginnings it th f dn i o , abls i , e to perfor mseriea difficulf so t field work excellens. Thin a f creatins o si y wa t ga "esprit-de - corps" that tends to keep people together. If the leaders remain active, newcomers can be t inttrainepu o d wordan k very rapidly.

29 Try alway o t chooss e people wit a stronh g character, abl o takt e e decisions independently. They wil difficule b lmanagee b o t t wil dbu l perform their work even ni difficult conditions. In a developing country patience is an essential quality. All kind of difficulties will aris evern i e ye performe b tas o kt wild an dl certainly increase wits it h complexity. You can be asked to help to unload a truck, to evaluate a boat and its crew before hiring it or, on the other side, may be called to solve complex mathematical modelling problems with sometimes incomplete data. Our group is a direct creation of IAEA and, we hope, one of its numerous successes. All trainine stafth e bees th ha ff ng o performe IAEy db A specialists, more tha ndozea themf no . Some r countrcamou o severar et yfo l missions, from France, Denmark, Israel, Spain, USA, Yugoslavia, Germany. Sinc beginnine eth thoughs wa t g i trainin f to tha besy brin e o grout e th twa gt s th gpwa experts to our country to perform a very definite task. This asked for longer missions than the usual, in general divided into two parts. All of our first field works of importance have been oriente expertn a y db . Durin gmissioa expere n th s onltask e ha tyon traio t : ngroua f po people; this increase e efficienc th e processs th e expertf o Th y. s were permanently accompanie morr o e e memberon y dstaffr b ou ,f so includin g weekends. Some played soccer, volleyball or swirnming; Dr. Plata Bedmar proved to be also an expert in "truco", a Brazilian card game. This helped to develop a relationship quite different from a purely technical one: we became friends. The efficiency of the process was thus further increased. These first words hav differenea t objective than simply tellin histore groupr gth ou f yo . We are actually trying to give some hints to other groups in developing countries that may be intereste worn di k wit applicatioe hth tracef no r techniques. It is our deepest feeling that the future for the application of tracers belongs to developing countries. Whe countrna y enter nucleae sth r field groua , usinr pfo g radioisotopes in industry, agriculture or engineering problems is always considered, since these applications belong to the clean part of nuclear energy. Another advantage is that the equipment needed to perform valuable experiments is simple and unexpensive: with a good and robust scintillation counter, a ratemeter, a graphical recorder, a sealer, a computer and a lot of disposition it is possibl perforo et m usefu eved an nl complex studies. Besides that it is normally easier to obtain the necessary authorizations to perform a field work in developing countries, since the phobic opposition to nuclear energy is not so countriee stronth Firse n i th s gtf a s o World generan I . gooa l d radiation protection plan based on the reccomendations of IAEA and presented to the licensing authorities is sufficient and all procese vert th no ys s i tim e consuming. There are enormous opportunities to apply nuclear techniques in developing countries, mainl areae th f sedimensn yo i pollutiod an t n studies; mos thef o t m have already been solved n developei d countries. Eve Braziln i n r grou s ou studie, ha p e majorit e mosdth th f to y important harbours; thu demane sth sedimenr dfo t movement studies with tracer declinins si g lase inth t years compensato T . , dispersioit r efo pollutantf no majorite s th respond r fo yw sno requeste ofth s receivedexpectes i t i t Bu d. that, wit incredible hth e developmen aree th af o t of mathematical modelling of coastal phenomena, tracers will again rum into operative instruments: they are a powerful tool available to calibrate a model, thus giving his user an increased confidence on the results obtained from the computer. Another positive e interespointh s i f tIAE o t n introducinAi g these techniquen i s developing countries through regional projects, like ARCAL in Latin America. These projects have been extremely useful in the training of new specialists in the nuclear area and contribute

30 to equalize the nuclear knowledge of the different countries involved, and also in promoting collaboration among the countries in the region. To finish this unusually long introduction, this Reviee coveo th t l y wal rtr wilt no l possible applications of nuclear techniques to sedimentation and erosion studies. Only the most important ones, fro engineerinn ma g poin viewf o t , wil exploree b l theid dan r practical aspects will merit considerable emphasis. We expect that this approach will increase its utility mainly for groups that have the difficult task of surviving in developing countries.

SEDIMENT TRANSPORT AND THE ENVIRONMENT

Introduction We live in continents and islands, where the natural action of the rain and the winds, associated with the human intervention (sometimes disastrous), affect the morphology of the soil. The runoff produces soil erosion, water and sediments are then transported by the action of the gravitational force to lower regions and the sediments, depending on their grain size anobstaclee dth s encountered coastae th t reacn lno ca ,area r hnaturae o Th .foy r thiwa l s flow of wate sedimend riversran e th e ,tar whic h have different shape sizesd san . The transport of water and sediments is an important environmental phenomenon of very complex nature (tridimensional and time dependent). It poses the following question: what happens when boundaries of a water flow are constituted of sediments which can be set into motio flowe th y ?nb This comprise erosione sth , transpor depositiod tan sedimene th f no t grains. The flow of water alters the boundaries of the flow and this change affects, in turn, the flow iterativ n itselfa s i t I . e process. The interdependence of the factors involved in practical hydraulic and sedimentological problems is so complex that a complete analytical solution does not exist. The knowledge of the structural geology, hydrology and river sedimentology (the natural processes in rivers) are the key for the understanding and forecasting of the changes occuy tha ma teacn i r h particular systemnaturao t e du ,l causeo artificiat r o s l ones (soil management, constructio f reservoino r dams, dredging work d constructioan s f traininno g walls with navigational purposes, etc.). Erosion problems arising from either afforestatio r deforestatioo n n scheme n laki s e catchment basins can contribute to the reduction in the effective life of man-made lakes behind reservoir dam r poweo s e interceptior th barrages o t e f sedimentDu no . thesy b s e structures, channel degradation may develop downstream. Oothee nth r hand marinn i , e environment naturae th , l causes actinsedimene th n gi t transport are different and even more complicated relatively to those occurring in rivers. Factor e takeb o nt s into account are: wave action; winds; current f differeno s t origins actuating in various directions in open sea and bays; fluctuation of the sea level due to astronomica d meteorologicaan l l tides, increasin e regiogth f influenco n f waveo ed an s currents in the shore profile and causing the reversal of the current in estuaries; mixing of fresh and salt water in estuaries and its consequences to the behaviour of fine sediments in suspension. Furthermore t shouli , consideree db d tha l thesal t e hydrodynamit c agentac y sma simultaneously in a given water body. The progressive occupation of the coastal zones requires an increasing human interventio studied nan adapo st coastae th t l regio thio nt s occupation. Several examplef o s

31 human interventions and studies related to sediment transport in the marine environment can be mentioned:

Capital or maintenance dredging of access channels to harbours, turning basins and berthing areas; Monitorin e sedimentatioth f o g n i existinn g dredged area r o predictins g the maintenance in future ones; Selection of spoil disposal areas for dredged material and study of the efficienc selectee th f yo d dumping sites; Constructio f o coastan l structures : sucas groinsh , jetties, detached breakwater wallsa se d ;san Artificial beach nourishment, harbour inlet by-passing schemes, locatio dredgind nan sanf go d traps; The associated sedimentological studies related to the response (accretion or erosion) of the shoreline to the coastal structures (item 4) and the works mentioned (item 5), require a knowledge of the littoral- cross-shore th drifd an t e sand transpor nearshore th n ti e region; Temporary excavation below natura le buriath depthf o pipeliner lfo s s and cables, which can present various problems, mainly in the shoreline region; Reclamation work e n i estuarieinfluence th s losf th o tidad sf an o lse volum sedimentare th n eo y regime.

Most of these studies and interventions are inserted in the discipline of Coastal Zone Management. Nuclear techniques applied together with conventional techniques and hydraulic measurement solvo st e sediment problem thin si s arealsd rivean oan i r sedimentologe b n yca seepowerfua s na l tool, provided the usee yar d with knowledg cautiond ean .

Some sediment characteristics

Fopurpose rth presene th f eo t critical Revie f artificiao e wus e Papel th radioactiv n o r e tracers and nuclear gauges in sedimentological studies, it is interesting to highlight some definition propertied an s f sedimentso , importan comprehensioe th r fo t behavious it f no n i r different environments.

Classification of sediments

Sediments under study can be classified by its grain size, from clay to boulders. Several size classifications exist. One of them, taken from [1] and proposed by British Standard, is:

Boulders > 200 mm Cobbles 200-6m 0m Coarse gravel 60-20 mm Medium gravel 20-6 mm Fine gravel 6-m 2m Coarse sand 2-0.6 mm Medium sand 0.6-0.2 mm

32 Fine sand 0.2-0.0m 6m Coarse silt 0.06-0.0m 2m Medium silt 0.02-0.006 mm Fine silt 0.006-0.002 mm Clay < 0.002 mm

particlee sizth terminae s f it eTh o d san l fall velocity (fall velocity under steady state conditions, where the drag on the particle is equal to its submerged weight) are the most important parameters relatin sedimene gth t properties wit theoriee hth graif so n motion. Broadly speaking sediments can be divided into cohesive and non-cohesive ones. Silt and cla cohesive yar sedimentd ean s having grain size from fine san bouldero dt none sar - cohesive ones differencg . Ther bi behavioue a th s ei n i e f thes o rclasseo etw f sedimentso s when submitte hydrodynamio dt c actions n casI . f cohesiveo e sediment resistance sth o et erosion relies on the strength of the cohesive bond between the particles. Once erosion has taken place, cohesive materia becomy ma l e non-cohesive relativel furtheo yt r transport i t bu t can flocculate whe regiona salinf no e water (e.g. estuary mets )i .

LOAD BE D

BED MATERIAL / \ SEOfMENT TRANSPORT TRANSPORT \ / (MECHANISM)

SEDIMENT TRANSPORT / \ SUSPENDED (ORIGIN) \ / LOAD

VrASH LOAD

Figure 2.1 - Classification of transport

Modes of transport

Sediments can be transported by the water flow, in different ways, either in suspension (suspended loawasd dan h load (bed-load)d alonr be )o e gth . Figur show1 e2. relationshie sth p of the various modes of transport. Bed material transport is the transport of the size fractions that are present in the surface layerrivee th rf so bed . Dependin hydraulie th n go c characteristic graie streae th th nd f mso an size materiae transportee b th , y ma l suspension di n (suspended loadclosn i r e)o contact with the bed (bed-load). Wash load is the transport in suspension of fine particles that are not found in appreciable quantities in the bed. The amount of wash load in a reach is not determined by the

33 hydraulic parameter e streama functioupstreae th s th i f t o f sI o .n me b supplyn ca t I . significan reservoio t t r sedimentatio estuariesn i d nan presencn i , morf eo e saline waterd san other factors t flocculatei , s wit consequenha t increas settlinn ei g velocit tendencd yan o yt deposition.

Sedimentary processes and measurement of sediment transport

e applicatioTh f nucleao n r technique sedimentologican i s l studies reache e threth s e environmental systems (rivers, estuarie s beeha ncoasts)t d I e mentionesan th 1 . 2. n i d complexit f yo sedimen t transpor rivern i t ( sunidirectiona quasi-steadd an l y flows). This complexity increases even more when dealing with sediment transport in coastal regions. For a general background on this subject, the reader is referred to [2]- page 7 to 20- where one can fin verda y clea rsam e andth t e,a time, concise explanatio sedimentare th f no y processes (interaction betwee watee nth sedimene r th flo d wan t transport rivern )i , estuarin coastad ean l environments. For specific applications of nuclear techniques, which will be seen in the remainin thif go s paper, some detail thif so s interactio highlightee nar eacr dfo h specific case. The prediction of sediment behaviour from flow parameters and the direct measurement thif so s behaviou normae rar l tasks that performehave b o et d when dealing with environmental and engineering problems. stude th sedimenf yr o Fo t behaviour mads i e physicaf eo us , l models with movabld ebe and mathematical modelling lattee Th . r have been more widel decadeylaso e useth tw t r dfo s because of the high construction and operational costs, doubts on the similitude and the inflexibility presente physicay db l models. These shortcoming physicae th f so l modele ar s more pronounced in river morphological or estuarine applications, where large areas to be represented deman verticada l distortio modele th f nverticallo .A y distorted mobil moded ebe l doe t scal roughnesd no s ebe s correctly impossibilite th d an , f scalinyo threshole gth d dan settling velocities of the natural sediment has given more space for the use of numerical models. Sensitivity analysis by mathematical modelling, in which the various parameters governing the physical processes are varied systematically, can give insight into the effects of aggregatio d settlinan n g velocitie e dynamith n o s c behaviou f cohesivo r e sedimentn i s estuaries. Moreover, it is virtually impossible to represent, in a physical model, the behaviour of fine sediments submitte aggregatioo dt n processes: inorganic salts promoting salt flocculation; organic compounds producing organic aggregate d bioflocculationan s ; organisms sucs a h copepods, mussels, tunicates, etc., transforming fine-grained suspended matter into pellets whose settling velocit mans yi y times greater tha constituenne thath f o t t particles [3]. Physical models using sand or light-weight mobile materials are still employed for wave-dominated coastal studies (e.g. shoreline region response to coastal structures; design of dredged access channel d localizean ) d river engineering problems (e.g. morphological influenc traininf eo g wall thein si r vicinity). Field measurement programmes of the hydraulic parameters and sediment movement are relevant for each particular site under study. They represent a first step in a predictive process that may subsequently make use of a hydraulic model if the complexity of the hydraulics canno treatee tb analyticay db l tools.

34 Measuremen hydraulif to c parameter physico-chemicad san l site dat achieves ai e us y db of various instruments: water level, tide and wave recorders, recording current meters coupled with conductivity and temperature sensors and fixed or moored at convenient sites and depths, alsd manney oan b d instrumentatio profilinr nfo watee gth r column. Measurement of sediment movement can be performed by direct observation and monitoring or with use of tracers. In the first case, the quantification of the suspended sediment movement requires a combination of simultaneous measurement of sediment concentratio currend nan t velocit fixet ya d stations (Eulerian approach) determinatioe th r .Fo n concentratione th f o immersef ,o samplee us e takee dth s ar bottle y npumpinb y e b r ar so d gan subsequently analise laboratoryn di . Normally, hundred samplef so necessare sar quantifo yt y suspendee th d sediment transpor crosa i h t s rapie sectio th estuary n riveda o a t f r no e ro du , variatio e concentratioth n ni n with timwitd ean h depth thin I . s s interestini way t i , o gt perform "in-situ" measurement of the concentration using special gauges based on the scattering or transmission of light, sound or radiation. For the direct measurement of bed-load transport, devices to be filled, such as traps and bottoe watee th basket th n i f m rt o coursespu usede t thes ar normall e bu ,y ar t adequatyno e because they interfere wit flowe hth , caus e dificul ar loca d o t ltan disturbancd be e th f eo position. nexe Inth t chapter detail givee sradioactivf ar o ne abouus e th t e tracerstude th f yn o si suspended sediment and bed-load transport. In chapter 4 it will be seen the use of nuclear gauges for the "in-situ" determination of suspended sediment concentration and density profiles of fine material deposited in reservoirs, access channels, turning basins and berthing area harbouf so r installation estuarind an sy builba e n environmentsi t f o d . Finallyen e th t a , chapter 3 and in chapter 5, case studies are presented. Nowadays, specialized hydraulic institutions offer relevant combinations of field measurement physicad san mathematicad an l l modelling facilities, utilizin mose gth t recent techniques and scientific achievements, in order to solve environmental and engineering problems related to sediment transport.

ARTIFICIAL TRACER SEDIMENTOLOGN SI Y

Introduction Les talu ta klittl e about tracer methods e dealin, ar sinc e gw e mostly wite th h engineering aspects of the behaviour of sediments and tracers are usually a quite pragmatic approac mano ht y engineering questions. They provide response long-tere th o st m interaction between the sediment and the flow processes that act over it, since they are able to integrate all the actions suffered by the sediment during the observation period. Thus they are not ideally suited for short-term studies of the functional relationships between sediment flux and hydrodinamic actions, as it occurs in tidally dominated movements [2]. Since most engineering application concernee sar d wit hwela l defined site t wouli , e db vera y lucky circumstanc fino et d some natural tracer that would provide informations about e sedimenth t behaviou aree f interestth ao t a r . More generalized utilizatio f tracerno s only became possible with the advent of artificial tracers in the 1950's and 1960's. From this time

35 on, tracers with radioactive or fluorescent properties have been used to simulate sediment movement, sinc accurate eth e matchin propertiee th f go naturaf so l sedimen they b t n became exequible. At that time tracers were considered almost as a panacea; it was thought that they could solve almost any problem found in hydrology and sedimentology. Unhappily this was not true and only the applications where the tracer method was really important have made their way through our days. The first experiments were largely qualitative and much work was done to develop technique conditiond san s necessar traceo yt r application specifio st c problemse W . always looked anxiously toward publicatio e pioneere papesth th w y ne rb thia n s i f nso field: Crickmore and Lean [4], Hubbell and Sayre [5], Courtois, and Sauzay [6]. It is our feeling that e quantitativth ee movemenstudth f o y f bottoo t m sedimens highlighit d ha t t wite th h publication of the thesis of Guy Sauzay [7], which studied carefully all the aspects of the problem introducee H . dmethoa e balanc coune th r th f dfo teo rates obtained durine gth detection of a radioactive cloud, which enabled the determination of the massic flow rate of sedimente th . This wor firss ktwa presente Courtoiy db Sauzad san y [6]methoe Th . mors di e generally called the "spatial integration method" and the overwhelming majority of the studies movemene ofth bed-materiae th f o t base. e it lar n do Three artifical tracerconsideree b n sca studier dfo sedimenf so t movement: radioactive tracers, activable tracer fluorescend san t tracers. Radioactive tracers have the advantage of versatility: they can be used for gravel, sand, silt and clay movement studies. Moreover, they enable direct "in situ" detection of the material, which means that the scanning of the tracer cloud is always done with open eyes, a great help in planning the detection strategy. And yet there are tracers able to cover a large spectrum of half lives, from ^^Au (2.7 days) to ^Ag (253 days). For the ordinary applications selectioa , thref no four eo r radioisotope sufficiens si almosr fo t l experimentsal t . Onchoosen eca exampler fo , , l^Au (2.7 days), l^N u ddays( 192id an ) r (74.4 daysr o ) 46s days)4 c(8 comparisonn I . experimenn a , t usin activabln ga r fluoresceneo t tracer will demand the definition of a sampling grid plus long and boring sample analyses. It is important to note that the definition of the region of maximum activity is very important to the total recovery of the activity injected. During direct detectio tracee bed-materiaa th f n i nro l movement experimen have w t e been obliged to perform several narrow-spaced (10m or less) detection lines to obtain a good definition of the peak of the cloud. It is not, in our opinion, very probable that the same kind of resolution could be obtained using a sampling grid. Obviously, only y-emitters are used in sediment movement studies with radioactive tracers. There are here two options available. It is possible to use a ground glass doped with an activable element, previously irradiate nucleaa n di r reactor labeo t natura e r o th ,l l sediment with the radioactive tracer. For sand studies, glas almoss si t universally used mors It . e important advantag thas ei t mass-labelling is obtained instead of the surface-labelling that results from the fixation of a radioisotop grainse th o esurface-labellingt n I . e morth , e importan radioactive t th par f o t e material will be fixed onto smaller grains and this can not be accounted for during the detection. This method will thus demand the use of a very narrow grain-size distribution. The problem of the representativiry of ground glass to simulate sand grains has been long satisfactorily solved, sinc possibls i t ei obtaio et n labelled glass wit same hth e grain-size distribution, specific gravity and shape of natural sand grains.

36 In the case of silt and clay, both options can be used. The labelling of fine sediments wit radioactivha e tracegeneraln i , ris , quit performee b e n e th sitsimpl f ca th e o t d da e an experiment e transpor Th e shielding. th f o t s necessar proteco yt t people against radiation, whe kilograe n halon r fo irradiatemf o d glas beine sar g used thes i , n avoidable case f th e o n I . the labelling of mud with ^^Au, the only thing to be done is to dissolve metalic gold with aqua regia, neutralize the solution and proceed to a careful mixing of the material and the radioisotope, a very simple procedure that can be performed at the deck of the injection boat dredgee orth r [8]. Muc bees timhf o discussio ha t ne- lo spen a defind o t an n - f finelei y ground glas5 s( to 40 ^m) could be used as a tracer for silt and clay. From an engineering point of view, it seems clear that glasadequatn a s si e tracer, sinc limitee eth d numbe f radioactivo r e grains, after thorough mixing with mud, will clearly follow the movement of the enormous quantities of grains into which the dispersede yar . Thi s stilsi l ensure cohesive th y db e propertief o s mud, that hel incorporato pt groune eth d mase glas th movement n si o s t ; this property will discrets a mov o t caust d no bul n ed i e mu particle kan s carryin graine gth s wit. hit We adopted the following approach: for experiments of short duration, silt and clay are marked by dissolved gold; for longer experiments, glass is mixed directly to the mud. The objectiv easo t labellin e s ei th g procedures; bot simple h ar hel d decreaseo an pt e radiation doses received by the team. For coarse gravel and pebbles, the method is to insert a radioactive tag in each pebble, which limits the number of pebbles to about 1000 for each experiment. For fine and medium gravel, surface labelling is the only possible solution. In relation to fluorescent and activable tracers, the problem is the blind detection, no feedback being received to guide the detection work, with the exception of fluorescent studies on beaches. Besides that, the costs involved are still higher than those related to radioactive tracers, sinc samshoule e th e on e ddetectious n technique latted san r perfor analysie mth f so each sample - which means that they are also more time consuming. The only advantage is to avoid radioactivity; they are only justifiable in countries where the legislation for the use of radioactive material is very stringent, or in very particular locations. It can be put. additionaly. that an excessive concern about the use of radioactive tracers s greatlha y hampere developmene dth e applicatioth f o t f nucleano r techniquess i t i s A . known, sediment studies with radioactive tracer limitee sar smala o dt limmensn area f ao e ocean (or other water body); the impact in the ecosystem introduced by an experiment is evidently despicabl demonstratede b thin d sca worlan r e- ou rarelt s di Bu . y logical; just look aroun seed dan . itemw Thine :s a radiatio leado t s su n safety standards.

Radiological safety standards

As pointed out before, the extent to which radioactive tracers will be used in the future depend largely on the demands put by regulatory organisms over the radiological safety standards that must be met. In any mission in which IAEA is involved, the technical people concerned receive the standard safety procedures recommende e Agencyth y b d e handlin,e th bot th r d fo h an g transportation of radioactive material. Based on that, a radiological safety plan is established so to ensure that all the operations with radioactive material at Curie levels are performed in

37 such a way that undue exposure or contamination of the personnel involved will be avoided, includin regulae gth rboat e creth f w. o Sinc operatione eth t complicatedno e t ar sno s i t i , difficult to ensure that dose levels will be kept within the permissible levels. After injection tracee th , r wil submergee lb d underneath several metre f waterso , which makes negligibl probabilite eth y thapersoy havy an t nma direcea t contact wit . Tracehit r particles demonstrates a , experimentsy db , disperse rapidly amon naturae gth l sedimena d an t decrease in concentration quickly results. Thus, the public, even in the worst hypothesis, will not be exposed to more than a few tracer grains. It can be shown that in a carefully prepared experiment some tens of grains, even if ingested, will result in doses well below the permissible levels. This approach induce Frence dth h grou tracef po r applications, probabl mose yth t active in the world and to which school we belong, to establish guidelines that proved acceptable to their public safety authorities. They are based upon two aspects: the maximum activity of a single release and the maximum activity of individual grains. firse tTh assumptio tha s injectenmase i e b th t o st d reason y wilt surpasb , no l f kg so 1 s reactor spac weigh d shieldine ean th f to g necessar protecyo t greata t volume reasonine Th . gs i to limit the maximum activity per grain, to assure that, even if ingested, it will result in one tenth of the maximum annual permissible dose. The total activity of a single injection is assesse multiplyiny db g this numbee valuth y eb totaf graine o r th lf straceo re masson r Fo . millimeter size sand grains, this activity is of the order of 2Ci (74 GBq) for 46$c, 192^ 1827^ 198AU. This activity is sufficient for most of the applications - and even larger than usually necessary. The injection of an excessive activity will result, in the case of bottom studies difficultien i , s during detection: sometime surpasn ca countinu e sth syo g capacitf yo the detection equipment (saturation). We generally work with activities in the order of 500 i (18.mC 5 GBq). Shoul e samth d e approac e adoptehb r finefo d r grains e maximuth , m allowable activities woul excessivee db maximue :th m activit thus ywa s fixe i aboun di C 0 1 t (370 GBq) per injection. In United Kingdo approace mth somewhas hi t differen considerd an t aspectso stw e Th . first one are the site-specific circumstances, mainly the expected sediment mobility. The second is the maximum activity of each grain, which is fixed in 0.1 uCi (3.7 KBq) for 46§c or equivalents it . e activit Ith e injectef b o yt s realldi y important e predictioth , e dispersioth f no s ni difficult and the economical aspects are favourable, it is possible to perform a pilot experiment usinbettea t ^^A1 gge r knowledgo ut sitee th .f eo Thi rarels si y necessaryn i , general, since you can have a good idea about the tracer dispersion based on hydraulic data of nature th region bottof e eo o th d nman material.

Practical applications of tracers to sediment movement

Afte perioa r whicn di h only qualitative results were obtainable ,dominane sucth s ha t directio f movemeno n s meait r no t velocity, almos l experimental t s nowadays seer fo k quantitative results. Afte shora r t presentatio methode th f no s use quantitativr dfo e studies shale w , l briefly present some considerations covering the principal applications of tracers to sediment movement.

38 We think that another aspect should be stressed at this moment: more the time passes, more important is the interaction between the tracer specialist and hydraulic engineers. Today nearly all the experiments are planned to include the collection of data on the more important hydrodynamic parameters. They are used both to interpret fully the tracer data collected and to make forecasting e sedimenth f o s t behaviour. Tracer studie expensive ar s thud e an eth s number of experiments to be performed is necessarily limited. The data on the parameters that induce movement are essential, since extrapolation of the results obtained during an experimen n generai s i t l necessary o approache Tw e used. b n , ca sdependin e th n o g characteristic countre th f so y wher liveu gooeyo A . d collaboratio establishee b n nca d witha hydraulic institute or the same personnel involved with tracer work can be trained as hydraulic engineers. We began using the first approach; later on, we moved to the second one. Presently membere th grour ou traine e f psar o tracen di r application jobe th ; n specializatioso n courses alwaye ar s performe somn di e area relate hydraulico dt hydrologyr so . After all these years of work, a sentiment remains: with the evident exceptions, people devote traceo dt r applications hav t beeeno n abl o shot e hydrauliwo t c institutee th l al s f nucleao potentialitie e us r e techniquesth f o s e feeW .l that this lac f communicatioo k n severely hindered the number of studies that could have been undertaken. May be a programme to correct this point could be envisaged for the future. To simplify the presentation, quantitative tracer studies will be divided into two categories: studiesedimend be f sstudieo d an t materiaf so l discharge suspensionn di , natural artificialr o .

Studies of bottom sediment movement

The Eulerian approache measuremene th o st movemend be f o t t will onl citede yb , since its practica vers i e y us llimited ; obviously, the extremele yar y importan r studiefo t f uniso - directional fluid e Euleriaflowsth n I . n approach e traceth , measures i r fixea t da d cross- section downstrea e injectiomth n point; afteinjectione th r passag e tracee th ,th f reo cloud must be completely recorded at a fixed station. There are two alternatives: the time integration method and the steady dilution method. Both have two limitations: first, the measuring station must be sufficiently distant from the injection point so that the mixing over the flow field has occurred (jcdt becomes independent fro measurine mth g point); second e floth ,w muse b t steady for all the detection period (ôQ/ôt = 0, where Q is the liquid flow rate, c is the concentration and t is time). The second condition is hard to fulfill since the passage of the labelled bottom material through a section is so extended in time that variations in the flow rate will evidently occur. These method thee sar n rarely used, excep laboratorr tfo y studies. The Lagrangian approach uses the complete scanning of the radioactive cloud at different times onle Th y. conditio supposo t s ni e thatracee th t r distribution remains constant during the time interval of each detection. Sediment movement is obtained from the quantified differences between successive detections methoe Th . uses di praticalln di studiee th l f yal so bottom sediment movement. The approach is used in the "spatial integration method", whose principal version is the "count-rate balance method", "total count rate method" or simply "balance method" [7]. Its great advantag appliee b n thas non-steadeca i o d t t i t y transpor omni-directionao t d tan l flow. It integrate e effecte hydrodynamicath th l f o al s l agents that have acted upo e bottonth m materia intervae th n i l l betwee detectionso ntw .

39 A stud f sedimeno y t dynamics using radioactive tracerprinciplen i , is s , simplea : labelled sedimen similas ta possibls ra naturae th o et l sedimen liberates i t regioe e th b t da no t studied; the transport of radioactivity is determined by radiation detectors towed by a boat whose positiodeterminee b n ca npositionina y db g system completA . e scannine th f go radioactive clou s namei d a ddetection ; comparison between successive detections will provid informatione eth s necessar calculato yt e transport parameters bed-loan I . d studies, they are mainly the direction and mean velocity of transport, the thickness of the moving bed and the bed-load rate of transport. The practical performanc experimenn a simpl s f a eo t this no ea s i t succint description tend showo s t logistice Th . s involve fiela i ddh tes quits i t e complex and, besides that, there are the difficulties inherent to work hi water bodies (agitation of the sea, boundaries formed by river banks, dirty bottoms hi estuaries). Beginning wit tracee hth r release (injection), some conditions mus fulfillede b t e Th . tracer must be deposited over the bed as a thin layer to enhance its rapid integration and mixing with natural sediment. Depositio ncarriee b mus t t morphologicallda no t y peculiar points, nor must be performed in a period of high waves or high tidal amplitudes, during which dynamic thent effecta e - ar smaximum tracee Th . r mus releasee b t d ove aren a r a large enough to be considered as representative of the region to be studied. Since the injection is frequently mad remotely eb y openin gdevica e containin radioactive gth e tracer e usuath , l procedur case th opef sano t eo injecto e n ei s dni th heigha t a r t abov bottoe eth m deemed sufficient to provide a reasonable horizontal spread of the tracer particles. Fall velocity of the particles and measurement of the currents at the moment of the release can give some hints abou necessare tth y height. A very concentrated injection, besides the risk of being non-representative, will give origi regioa o n t higf no h activity thasaturatn ca t detectoe eth r whe t passeni s ove . Worsrit t than that, a part of the radioactive material will remain for a long time at the injection point. Both facts will invalidat obtentioe eth correca f no t tracer balance. bedd obtaio mu t , case a I nf th well-definene a o d tracer patc difficula s hi t task. Evef ni injectioe th mads ni e nea bottome rth tracee th , r particle stily lsma mov r largefo e distances, since they can be advected by the flow before mixing to bed sediment. The period of slack water obvioun a s i s s indicatio releasa baya e madestuarn a r b n i nfo n o .i e et r Thi yo s precaution normally gives origi workabla o nt e tracer cloud open I . n sea, injection shale b l mad perioa n ei weaf do k currents. Normall a detectioy s madi n e soo ne subsequen th aftee releas o n t th i r r y o eda t determine cloud contours. During this detection, regions with concentrated activity are avoided, in order not to disturb the adequate incorporation of the sediment by the bed. e detectioTh s usualli n y mad usiny b e a robusg t scintillation detector, water-tight. attached to a sledge towed by a boat. The usual electronics is linked to the detector: ratemeter. sealer, graphical recorder, printer or a computer. Even if you use a computer, a graphic recorder is a very useful instrument to enable the effective participation of the specialist who guides the detection: human intervention is always necessary, both for the detection and for data analysis. The detection is made by mapping all the area over which the tracer is distributed, by trajectories as parallel as possible to each other. The region where the activity is more concentrated demands a thorough coverage, with navigation lines narrowly spaced: it is very- important to have a good definition of the peak of the tracer distribution, as it is also important fino t d clearl boundariee yth e cloud th difficulte f so Th . performinf o y googa d coveragf eo

40 e clouth d increases exponentiall realls i y a wity se agitatio e rough e hth seae th th f .I f n,o remai land n resultne o wilTh .u slyo wortht obtaino sacrificee e nyar th . Selectio adequatn a f no e importan n boaa s i t experimene t th par f mads o ti a d t ea an t previou sexperimentae visith o t l area t musI . t hav minimuea gooa m , lenghd cabi12m f o t n to protect the equipment and crew, enough space on its stem, where the mechanical devices locatede ar gooa d d,an winch. Sometime lucke ar u y enougsyo fino ht comfortablda e boatn ;i more remote locations, it is usual to hire a fishing boat - and then the boat crew must be trained prior to the actual performance of the experiment. The communication between the orientins i o wh gn navigatioma helmsmae th d nan n mus easye b t tablA . e with enough space navigatioe foth r n chart, drawadequatn a n ni e scale (remembe obligee b n ca ro d t tha u yo t perform navigation lines with 10m intervals), is mandatory. The speed of the boat must be kept f possiblei , , aroun metre dr secondon epe speee Th . d wil differene navigatb u l yo s a t e against the waves or in the same direction of them. The team to perform the experiment is in general composed by 4 or 5 people. One of them orient navigatioe sth thinksd n an vers i t yi : importan havo t e someone mor lesr eo s free to orient the helmsman and to define detection strategy. A second man takes care of drawing the detection lines, unless you have a computer on board. Some kind of code must be defined labeo t regione th l s where activitmomeny an t founds ya i picturt a t ordege n i ,n erca thau tyo radioactivite ofth y distribution. Abuss i thirn y dwitma electronice hth provided san s informatio plottee th o nt r about e activitieth s found , e recordee printebaseth th e b n d o d r y an r datama fourt A .n ma h necessar tako yt epositionine carth f eo g equipmen alsd provido an t e informatioe th r nfo plotter. Anothecabie taketh d standf n an o mechanicas e t rma carth sou f eo l equipmente H . permanently verifies if the sledge is moving smoothly over the bottom and warns the cabin if a region with rocks or duty bottom is being navigated. If the sledge is halted by same obstacle e mush , t immediately orde o disconnec t o sto t e board th pan t e detectioth t n equipment from the mains. Even using a steel cable to pull the sledge, there is always the dange electrica e breaa th f rf o k o l cable whe sledge nth stoppes ei debrisa y db . Tha vera s i ty unpleasant situation, since saline water will enter the scintillation counter. This induces an important remark: hav l youal e r equipmen doublen i t o avoit , e disastroudth s effectf o s Murphy's law. In tropical regions, normally the sea is calmer than in temperate regions. As an example, the highest wave recorded at Brazilian coast had a height of 6.7m. Winter conditions are evidently harde therd an r e wil some b l e day whicn si wile t workhon no l generaln I . , these roug conditiona hse s las t interfer t dayno thuw d onlo fe an s d s ya e very much with your plannin detectionse th r gfo . Thing more sar e difficul regionr fo t s wher weathed eba s likelri y to remain for longer periods: sometimes you need badly to perform a detection and sea conditions won't allow it. Seasickness is a point rarely cited, but that must be considered. It can be partially prevented by the use of some medicament. We have seen several cases of people that could not perform any useful work because of seasickness. Burnt diesel oil mixed with fish odour is particularly troublesome. Never drink coffee; lemo s gooi n s preventiona d . There ar e conflicting opinions about eating or not during a detection. The basic equation that give bed-materiae sth l flow-rat: eis

Q = pLVm Em, where

41 Q = bed-load flow rate (kg/d) p = sediment specific gravity (kg/rn^) L = transport width (m) Vm = mean transport velocity (m/d) = mean transport thickness (m).

The parameters to be determined are Vm and Em.

The mean velocity Vm of the bed material is determined by the distance between the centroids of the spatial tracer distribution divided by the time interval between the detections. The determination of E^ is a more difficult problem, since it is necessary to know the vertical tracer distribution. The most direct technique is to take cores as undisturbed as possible, followed by the sectioning of the core and the subsequent counting of the slices obtained. Since a single core represents only one point of the tracer distribution, this obliges to take a considerable number of samples. The majorit "counstudiee e th th e f yo tsus rate balance method" principls .It thas ei e tth count rate recorde detectoa y db functioa thicknese s i rth layee f no th f radioactiv o f r o s e material: the same activity will yield different responses as it is more or less deeply buried. If all the radioactive material is "recovered" during a detection, there is a mathematical relationship between the total count balance and the mean depth at which the tracer is located. This relationship is different for each vertical distribution of the tracer. To use this relationship, a previous calibration of the detector is made, based on a known activity, to determine the detector response to an unitary activity uniformly distributed over an infinite arecovered aan differeny db t sand layers. From this calibratio response n th detecto e th f eo s ri obtained, given generally in counts per second per microcurie per square metre. A detailed descriptio coune th f nto rate balance metho obtainee b [10]n d d ca an [7] n d i ,] includin,[9 e gth mathematical derivation and calibration procedures. Another metho o determint d e in-depth distributio e traceth e s th basei f r o nn o d observation of the propagation of bed configurations like dunes and ripples in a fixed or at several points levele Th . s reache troughy db s giv indication ea depte th f hno tha tracee tth n rca reach. Another possibilit o obtait s i yn longitudina d througbe l profilee th h f echoo s - soundings. An interesting suggestion has been made by Dr. Plata Bedmar to determine the transport multichannea depth f o suggest e e H . us e sth l analysee completth d an r e recordin- y e th f go spectrum of a buried tracer, covering both the Compton region and the photoelectric peak. As depte th h increases Comptoe th , n region will become more importan photoelectrie th d an t c peak will decrease transpore Th . t depth could thu determinee sb d afte previoua r s calibration at laboratory. We intend to explore this idea for experiments that are in course at Magdalena River, Colombia.

Tracers in the study of suspended sediments movement

The dynamice studth f yo suspendef so d sediment f capitao s si l interes problemn i t f so civil engineering, mostly for the definition of dumping sites for dredged material and in water pollution problems. In such cases we must know how a given pollutant or suspended sediment is dispersed, and we are led to study the dynamics and transfer properties of a cloud of

42 suspended material moving under current and/or tide effect growind an s g larger becausf eo the turbulen dispersivd tan e propertie watee th f rso environment. The most important results obtained from such an experiment are:

•The path and drift caused by currents; •The mean velocity of transport; •The turbulent dispersion coefficients that characterize the dispersion of sedimene th water-bodye th y tb ; •The e dilutiosedimenth f o n t (maximum concentratio n i function f o n time); •The sedimentation rates; •The area over whic sedimene hth depositeds ti .

After the deposition of the sediment on the bottom, the experiment proceeds using the technique stude th bed-loa f r yo sfo d transport .methodologica e Mosth f o t l aspects have been reviewed earlier, including the labelling of sediments, the release procedures and the detection and positioning systems e samth , e use r bed-loafo d d transport studies wit e evidenth h t difference tha detectoe tth mor o n s eri attache boafixee a t th sledge a a t d o t o d t deptht ,bu . Whe e verticanth l distributio e traceth s necessaryf i rno importann a , t parametet a r greater depthsextra-detectorw to boae n ,th ca t s kep position i t heavy nb y ballast verticar so l profiles can be made at fixed points during the intervals among the mappings of the radioactive cloud. For studies e relatedisposath o t df dredge o l d material o labellin, tw ther e ar eg alternatives possibls i t I . labeo e t ful e lth l loasuctioa f do n hopper dredge bargef o r ro s during the dredging operatio labeo t r no l onl ylimitea d amoun materiae th studiede f b o t o t r l fo , concentratioa instanc t a L 0 e4 200g/Lf no . The most common release procedur instantaneoun a s ei s injection somn i t ebu ,case sa constant flow-rate injection is highly recommended since the detection method is direct and much easier. Detectio agains i n Lagrangian, which means that several sucessive configuratione th f so radioactive cloud mus mappede tb . Sinc velocite elabelleth e th f yo d materiae th e b l wilw no l same of the prevailing currents, the detection is much faster and nervous if compared with bed-load experiments s absoluteli t I . y essentia determino t l e curreneth t field immediately before the release; a fluorescent tracer or any other dye can also be very useful to give an orientation about the initial movement and spreading of the cloud. An experiment with suspended sediment require versa y experienced grou boate boarn th o p f o .d o Ther tw e ear strategies and both will give similar experimental results. In one of them, the boat crosses the cloud transversall tried pasyo an st s directly ove regios it r f maximuno m activity. Thet ni make longitudinaa s l trajectory, crossin cloude th l ,gal trying agai fino maximune t th d m activity. The boat then proceeds to the new position of the cloud and remakes the mapping. A floa r fluoresceno t twile tracedy l r orieno beginnine r th boae e experimentt th ta tth f go , marking the region of maximum activity. After the mapping of some clouds, the crew will hav a gooe d controe situationth f o l , knowing quite well wher r wil) e clou(o th ebe l s di located, oriented by its sucessive positions in the navigation chart. Since this kind of

43 experiment last somr sfo e hours considerabla , e numbe mappingf ro performede b n sca , each one giving the transversal and longitudinal dimensions of the cloud and the position and value e maximuth f o m count rates. These parameter a dispersione inpu sr th fo wile t b l - sedimentation mathematical model, from whic resulte hth s beginnin e citeth n di thif go s item can be assessed. idean a n lI condition boatdetectione o usee th tw ,r thef ar so dfo me on ,performin e gth longitudinal crossing othee transversae th th rd san l ones. This will increase considerable yth experimente costh f to , which means that this techniqu commonlt no s ei y used. Another detection techniqu s i usualle y use n dispersioi d n experiments e boath : t performs a complete mapping of the cloud instead of looking only for the maximum activities. This limits the number of clouds that can be mapped, which will impair the determination of some parameters like deposition rates, that mus e baseconsiderabla b t n i d e numbef o r experimental results. The analytical method may be found in [9], [10] and [11]. Since in the case of suspended sediments the main transporting agents are the currents, it is always necessary to have a complete recording of them during the experiment. Simultaneously with the detection e cloudth e positioninf o th , droguef go s release e momen e th injectio t th da f o alsd t nan o during the crossing of the peak region gives the Lagrangean behaviour of the current field. These informations, coupled to current measurements at fixed points give an overall picture of the current field with time. A good knowledge of the current field of the region is very important to define the most frequent and the most critical conditions that occur throughout the year. o obtaiT n representative results, experiments shoul e performeb de mosth r t fo d representative hydrodynamic conditions, which is not always attainable. In general, during a field campaign, several experiments are performed and normally different conditions of the environmen studiede b n fiele ca t dTh . study must thu schedulede sb , taking into accoune th t period of the year during which the most important hydrodynamic conditions are likely to occur. This importance is defined in function of the objectives of the experiment. For instance, idumpina f g sit s beinei g chose s essentiai t ni havo t l e experimental data relative th o et hydrodynamic conditions know estimatedr n(o transporo )t dumpee th t d material e bacth o kt dredging region or to another critical site, like a beach or an access channel. Since we are not capable of controlling nature, experiments of this kind always have a non-deterministic aspect.

Final comments It is adequate now to make an evaluation of the positive and negative points related to the use of tracers in bottom and suspended-sediment studies and the problems that still remain partially solved. e firsTh t words wil directee b l peoplo dt developinn ei g countries that e intenus o dt tracers to study problems of sediment movement or effluent dispersion. Developing countries always have a factor in common: problems to be solved are popping around. Firstly, it is advisable to choose one problem involving important economic or environmental impact, in which tracer technique mandatorye sar contac o next e s i Th . t o thintd IAEo gt A presentinga

44 description of the problem, as detailed as possible. A first experiment must be supervised by an expert, sinc logistice eth s involve comples di therd dozene xan ear experimentaf so l details that are never presented in the literature. They can only be learned by experience. Probably the expert will hav performo et t least a ,missionso traitw ,o t team e firse e nth on tTh ., solve logistic problems o prepare mechanicat , th l al e l devices necessar e injectioth r d fo yan n detectio defino t electronicd e neth an s that wil usede seconb le Th . d mission wil dedicatee b l d to calibratio e detectorth f no , realizatio analysid experimentne an th f o s . Probably, should other detection campaigns be needed, the local team will be capable of coping with it. It is surprising the improvement of the local group that can be obtained with a two- months mission of an expert. The group will certainly be able, after this first experiment, to legsn ow . s walit y kb It is possible to perform such an experiment with a minimum equipment: a scintillation counter graphia , c recorder printea , theodolitesd an r resulte Th . ss goo a wil thoss e da b l e obtained with more sophisticated electronics; only the deployment of data will need more completede timb o et . People of all the world, j oui us.

Suspended-sediment transport studies

For experiments with suspended-sediment, it is our feeling that radioactive tracers are operational kinA . f studdo y particularly gratifyin definitioe th s i g f dumpinno g placer sfo dredging spoils. possiblIs i t studo et y firstl movemene yth suspendee th f o t d sediment and generaln ,i , its fate after the deposition can also be determined. Other option is to split the experiment into tw oimportan n case a parts th f eo n i , t spreae suspendeth f do d sediment ove bottome th r . Sometimes, results are spectacular and important economic goals are obtained by the reduction of the distance travelled by the dredger or the barges. It is advisable to perform this kin f experimendo t whe hydrodynamie nth c agent theit a e r sar wors t conditio relation ni o nt the return of the sediment to an undesirable location: always stay on the safety side. Other applications deal with the dredging procedure itself. Studies can be made to verify the efectivenes agitatiof o s n dredgin estuarien gi t harboura r so s subjec strono t t g tidal currents. The ideal positioning of the discharge tube of a suction dredger, for instance, can also be determined with tracers in the case of agitation dredging, as will be cited later (Alumar harbour case study-chapter 5). The same remark - radioactive tracers are the best solution - is valid for dispersion studies of particulate matter. A good example is the location of an outfall for the disposal of pollutants thin I . s case, sinc cannou eyo tpossibl e coveth l al r e hydrodynamic conditions. océanographie measurements become very important s necessari t I . havo yt evera y good knowledg currene th f eo t field throughou yeare th t , including statistical valueperiode th f so s when the currents have a disfavourable orientation. Based on that, a cost-benefit analysis will enable definition bese th tf locatioso outfalle th r nfo . case I nth dispersiof eo n studie liquir sfo d effluents, fluorescent tracer consideree sar o dt be an option, since radiation is avoided. It is also frequently possible to use a continuous injection of tracer with fluorescent tracers, easing both the detection and data analysis. With radioactive tracer, continuous injections are rarely feasible because of the huge activities necessary'.

45 Bed-load transport studies

Bed-load transport studies present different effectivenes function i senvironmene th f no t in which the performede yar . e cas Ith nf rivers o e , bed-load determinatio s possiblei n onle th , y problem being sometimes the river banks, that can interfere with detection procedures. Bed-load is only a fractiosedimene th f o n t transporte rivere th y , db mos f whico t h occur suspensionn i s s i t I . then a matter of a careful economic evaluation to define if the informations provided by a tracer experiment are worthwhile. In some cases, such as the artificial deepening (dredging or constructio traininf no g walls) with navigation purposes bed-loae th , d transport knowledgs ei very important. These studieimportane b n sca i areah t s severely affecte erosiony b d possibls i t I . o et quantify the bed-load transport and calculate the contribution of different sub-basins to the overall sediment transport. Another important application is the validation of the several hydraulic transport equations available. Afte definitioe th r mose th f t no adequat e transport formul rivere th r , afo extrapolation differenr sfo t flow-rate establishee b n ca s d wit hhighea r degre f confidenceeo . This type of information can be important when some kind of reservoir is to be built downstream predictoe th r effectivs it fo , f no e life. Result usee b s inpu da n scomputeca o t r programs designe evaluatdo t e sedimentatio confinee th n i d water-body. In the case of estuaries, bed-load studies with tracers are difficult to be performed due to bidirectional flow. Eve n studieni f suspendeo s d sediment radioactive th , e cloud tendo t s "explode" during tide reversal. Thi alss sha o happene bedsstudied n d i t sedimen mu Ne .f so t drift can be determined in some cases, mainly for sandy bottoms. It is suggested [2] that the tracer mass shoul dividede db totae , halth lf fbeino g introduce high-watet da r slac hald t kfa an low-water slack r open-seFo . a conditions, situatio s differentni . Tracers remai bese th ts na option for bed-load studies and part of this importance is related to tracer ability of integration of all hydrodynamic agents that act upon it. Problem determinatioe occuy th sma n ri transporf no t rate regionn si s where e mosth f to transport is observed during storm conditions, which is not unusual. The tracer can be spread over such a large area that artificial radiation cannot be detected anymore. We have observed this situation during experimental work and we consider this problem as a limitation to tracer use, when quantitative results are sought. Probably the solution can be found in coupling field experiments and mathematical models already available for computers and designed to evaluate transport rates. The experimental work, performed during a period when hydrodynamic parameters still enabl detectione eth , shoul usee db calibrat o dt modele eth . e samth en I lin reasoningf eo , another potentia f radioactivo e us l e tracer studyinn si g bed-load transpor open-sen i t quantitativs it ae regious o t s ni e result calibratior sfo crossf no - shore sand transport mathematical models, in relation to artificial beach nourishment works. To resume naturae th , l sorting mechanis frontae th y mb l actio wavef ns o beaca a n s o sh ha result that the coarser sediments find then- equilibrium position in the beach profile closer to the shoreline than the finer ones. Then, if coarser sand is dumped by a dredger, in front of a beach, it may be moved shoreward naturally, by wave action, and may fill the beach. Radioactive tracer, simulating this coarser sand, coul appliee db quantifo dt y this cross- shore sand movement at various depths and for different hydraulic and meteorological conditions, before the methodology of beach nourishment is decided.

46 A detailed hydrodynamic and sedimentological study of the area: wave climate, beach profiles, bottom sediment grain size distributio e seasonath d an nl variatio f theso n e parameter requires si d befor tracee eth r studie performede sar . It coul possiblee db , fro tracee mth r detection results obtaio t , n information aboue th t seaward limit of litoral drift, for a certain sediment grain size distribution, in a defined wave climate. The width of the reach into which littoral-drift occurs is an useful information for engineers that are using hydraulic transport formulas to calculate it. Remainin littorae th n gi l drift region, much informatio needes ni d abou . Unhappilit t y e detectioth t thia n s regio s almosi n t impossibl e conventionath n i e l way. Somw ne e techniques are being developed to work at this region and will be cited later. Our previous comments point agai problea o nt m already suggested have w : e failen di showing tracer possibilitie potentialitied san hydraulio st c laboratorie institutesd san . e classicaTh l application tracerf o s bed-sedimeno t s t studie suitee limitea ar s o dt d number of sites in each country, mainly for engineering problems linked to harbour construction or development and to the building of hydraulic structures hi the sea. Studies of bed-loae th d transpor ver t rivern i tno y e frequentsar , sinc knows i t ei n that nearly e mosth f o t material is transported by river flows as suspended sediment. In opposition, environmental concern is growing in all countries. The liberation of industrial effluents is now subjected to severe restrictions. Heavy metals, phosphates, chlorides, fertilizers, pesticides and particulates disposa problea s i l m tha l environmentaal t l authoritie seekine sar controlo gt mann I . y cases these effluent discardee b n ca s d without harming environmen f tracei n r me studie r o t e ar s previously undertaken. Since som thef eo discardee mar paniculatn di e form opportunitiee th , s for suspended-sediment studies have a tendency to increase. Diluted pollutants are also an opportunity for tracer studies but they are beyond the scope of this paper. There are however new applications of bed-sediment studies that need to be developed thee b yy an couldma d caus ereversaa expectativesf o l . Som themf eo , performe European di n countries citee ar ,sequence n di .

New applications for bottom sediment studies Long-term behaviour of dumped dredged spoils [12]. As it was stressed before, studies of sites for the disposal of dredging spoils are one of the most useful applications of radioactive tracers. In many cases it is possible to define a site that is entirely safe as a deposit, in which the dumped spoil will remain indefinitely. In other cases, the tracer studies are able to define the short-term behaviour of the sediment but information is still needed relative to its long-term destination. regioe Th n adjacen porte th Zeebruggef so o t t bes,e Anverth tf Ostendo d e san on s ei studied in Europe. Tracers have given an important contribution to the définition of disposal sites for dredged material and also to the definition of dredging methodology. It was found that the dumped material was rapidly resuspended by tidal currents, but there is no information available relativ s long-terit o t e m behaviour. This informatio f capitao s i n l importanc coordinatoe botth r hfo dredgine th f ro g environmentaworko t d san l authorities. The access channels to the ports cited above need permanent dredging to keep adequate navigation depths e e sedimenorigith Th .f o n t responsibl r thifo es siltation shoule b d determined possibilite On . direce th s yti returdredgee th f no d sedimen accese th o tt s channels.

47 19* £ S5*N

COASTAL RESEARCH STATION LUBIATOWO

SA' *30

Figure 3.1 - Location plan of investigation site (After Pruszak and Zeidler, I992-H3])

Another possibility is that the sediment comes from several mud banks located at the environs of the harbours. The origin of this sediment should also be determined. A study to define the long-term behaviour of the dredged sédiments covering a period of several month bees sha n propose [12]n di principas .It l objectiv verifdredgeo e t th s ei f yi d sediment deposite dumpine th t da g sites observee wilb r wilt o l no l t defineda d e timeth n si sedimentation zones. Sinc necessars i t ei determino yt e this behaviou tidb eeb floor d fo r dan conditions a doubl, e labellin s proposedi g . Furthermore e enormouth s a , s dilutions will prevent "in situ" detection of the tracers, samples must be recovered (30 per study) and subsequently analysed at a laboratory using a high-resolution Ge-Li detector for measuring the y spectrum between 0 and 3 Mev and long counting times (about 12 hours, calculated to detect activitie Ci/gs2 estimate1 " . Bq/10 4 r 0, o g n di The radionuclides selected have been 181Hf (half life of 45 days) and 160Tb (half life of 73 days), the first one for labelling the mud (sieved at 0.063 mm) to be injected at flood conditions and the second to be used at ebb tides. Three depositions are envisaged for each condition. Activitie r injectiont concentratioa pe si d proposeC mu 5 f ,1. o usin e g f dar nk o g1 250 g/L. labelline Th g metho fixatio e radioisotopee th th s di f no sedimente th o st , obtainey db the precipitation of their hydroxides from chloridric solutions mixed to suspensions of mud. This metho labellinf do bees gha n Hosli d studiean r Grooa e Bougaulny fo L d D b r , tfo Se r tfo obtainee HfTh . d labellin proves irreversible ha gb o dt physico-chemicae th t ea l conditions founoceane th t da . Measuremen f bottoo t m sediment transpor sure th f n zoni t e using radioactive tracers [13]. A study about beach changes and sediment movement was conducted in the South Baltic

48 a coastaSe l zone between 198 198d 3an 9 [13]. Systematic measurement beacf so h profiles coverin f coastlino m g3k e (FIG. 3.1) showed that this stretc f coasho t belong multi-bao st r dissipative ones, with an average slope of 1.5% (FIG. 3.2) and sand grain size D5Q - 0.22 mm. The bed changes are intense, mainly in the region of the inner bar (depths about 3 m). Ground glass with diameter betwee nlabelled 0.1 an 0.2d 5an m 5dm with 192jj beeg ha .n employe traco d t sedimen e kth t movemen three th en ti different subzone shore th f eso profile, shows a Figurn i e 3.2. ARE A, situateI regioinnee e th (50-6r th fror n f drba i ne fa o mth 0m shoreline), has depth h = 0.8-1.2 m. AREA II, 200-250 m away, with h = 2-3 m and AREA III, spaced 350-450 m from the shoreline, with h = 4-5 m, encompassing the outermost bar, which delimit seaware sth d boundar sure th ff zoneyo . Being the waves the main hydrodynamical agent in the sediment transport in the surf zone, for the sake of the study the wave climate was divided into two classes of events related wavo t e heights occurrin ) n storAREgi (A m : A II period s (H^g^N > 0.4m f higo ) h sediment transport rates and (B) low intensity 0.1 < HMEAN 0.3 m. These two classes embody all perceptible transport rates. < The movemen radioactive th f o t e trace s trackewa r d automatically e f closi ;th o t e shoreline, within a special 10x10 m steel frame (referred to as 'Spider') or from a boat, if far away fro shorelinee mth . Calibrated scintillation detectors were used.

16-05.87 15-10-87 28-CK.86 05.10.88 24.05.89 130989

-6

-8 200 0 80 400 0 60 Distance [m] Figure 3.2 - Examples of measured shore profiles estimates (After Pruszo d Zeidleran k , 1992-[13])

49 0 70 0 60 0 50 0 40 0 30 0 20 0 10

him]

longshore seoiment tronSpoM .'-.->>*»J {kg/mq ] h - 100 (WAVE RIDER]

5 Hmox'fte™ * '™ H ( r fo H =0.3-^0.5 m • • ~ « m 7 c h so T=tr6 s Tr4- S3

«max= 1.5* I T 0.5r1.0H= m 10 T-**«« l

Ikg/m- h ]

20 16 H = 0.2m 16 r 0.5 3 m 0. r s H U T-4 S 12 10 6 6- A' l 2- I

(After Pruszok ond Zeidler, 1992-[1331

Figure 3.3 - Sediment transport rate

50 Most experiments took place under oblique wave incidence. In case (A) events, longshore sediment transport prevailmose th td intensivan s e sedhnent transport occurn si AREA II: longshore transport rates Q ranging from 40 to 100 kg/(m.h). In the AREA I, closer regioe kg/(m,h0 th kg/(m.h)4 0 n AREf shoreline2 i no < o t d < Q )an Q A < < III5 .5 1 : :3. Under condition weaf o s r moderatko e oblique wave - scasevent) e(B - s(e.g . mean AREi longshore h th m ) A2 II 0. e < transpor H d wavan s te rat4 perio < e heighd T dan < 3 t bees ha n about five times smalle rmeasuree thath n ni d cas) evente(A s (FIG. 3.3) r cas.Fo e (B) conditions the longshore and cross-shore mode of transport are equally important, being 1.7:1 (13.5:8 kg/(m.h)) for AREA II and the cross-shore transport is usually onshore in this case (FIG. 3.4a).

pulse/s

overoge wove direction disposal

injection 19 89-09.U 12:00 measurement 1989.09.21 11:00

3doys (H= 0 20-r 030cm. T«3.1s)

Area (11 • .• * - • * . -....•..-. .-•-.•. shoreline . .'::-.-V F7 : _i ___ i ____ i—————— i ———— : — —i —————— i —————— 1 600m 500 400 300 200 100 0 reference level

21st Sep'89 to 7 Ocfes wove direction {-7doy 0.4m> H s )

600m 500 (00 300

(After Pruszo Zeidler,1992-USd on k D

Figure 3.4.a - Distribution of radioactive sand tracer from 14th to 21st September 1989 and from 21st September to 7th October 1989

51 groiw fe no diomeier= 6 s r> r===\/l (surface)

4 (bulk Iransport)

(After Pruszak and Zeidler, 1992-U33)

Figure 3.4.b - Schematic sand advection

Core samples of tracer sand have provided estimates of the vertical extent and distribution of transport rate in the bed layer. For case (A) events, the thickness of the bed sublayer 5 in which all grains move in bulk is 2-5 cm; under weak and moderate waves this thickness is only a few grain diameters (FIG. 3.4b), and it was found an empirical relation breakine linkinth d an gô wave height (Hb) 0.02= 5 : 7 Ffb experimentae .Th l relation between the volumetric sediment transport rate Q and Hb^.v (where v is the mean longshore current velocity) was: Q = 0.027 Hb^.v m^/s. Both relations agree with experimental findings of Krauss et al. [14], but are in disagreement with the results of Drapeau [15] by one order of magnitude. Pruszak & Zeidler [13] explain this discrepancy by an overestimated thickness of transport (5 = 10 to 60 cm) as pointed out in [13]. knowa s Ii t n fact tha higher fo t r waves ther tendenca s esane i th dr transporyfo e th n i t breaker performee zonb o et d mainl suspensionn yi questioa s i t .I n ope researco nt verifo ht y if such tracer technique, as applied in [13], is applicable to more severe wave climates. Experimental results obtained in laboratory channels under identical regular wave conditions shoued suspended sand sediment concentrationacoustie [16]L th s g/ A .0 8 c o t p su detectio t suitabl stem\ no ns e r measurinar sefo g suspended sand sediment concentration ni turbulent flo\\ with the presence of micro-bubles, such as in the breaker zone, the nuclear density gauge possibla e sar e alternativ thir efo s kin measurementf do .

NUCLEAR S GAUGINAPPLICATIOIT D AN G O SEDIMENTOLOGICAT N L STUDIES

Introduction

The knowledge of the concentration C of suspended sediment (mass of dry sediment in givea n volum waterf eo , expresse partn d i millior spe milligramr no importanlitrer n a s pe s )i t data for the evaluation of the consequences of the human intervention in hydrographie basins: erosion problems arising from either afforestation or deforestation schemes and also from

52 agricultural and mining activities in lake catchment basins. The "in situ" measurement of high concentrations (greate 1000mg/Lro t tha0 n50 suspendef )o d sediment (sand, clayd silan t n )i the feeding rivers and of the bulk density of fine sediments (silt and clay) deposited in reservoirs e applicationar , f nucleao s r gauge r obtaininfo s e sedimentologicagth datr fo a l balance of the system: lake catchment basin-reservoir. n estuarinI d coastaan e l environment e nucleath s re employeb gauge n r ca s fo d measuring the bulk density of fine sediments deposited in access channels, turning basins and berthing area wele harboursdredgersf f th s o o l n i d an ,. These measurement relatee sar d to the optimization of dredging works. There is also a potential application for nuclear gauges in measurin hige th gh suspended sand sediment concentratio energetie th n i c wave breaker zone [2].

Principles in which nuclear gauges are based

The absorption (photoelectric effect) or scattering (Compton effect) of electromagnetic radiations (X or y) emitted by an artificial radioactive source are a function of the concentratio bule th kr no densit mixture th f yo e sediment-water possibls i t i thii y h ,o e t swa construct nuclear gauges base thesn do e principles, provided thasystee th t mcalibrates i r dfo known concentrations. The volume of influence of nuclear gauges is proportional to the energy of the electromagnetic radiation of the radioactive sources: 8-10 cm diameter for l^Cd sources, sourcem A greated 1 san 24 r 20-4rfo diameterm 0c r sourcesfo highef so r radiation energs ya 137Csand6°Co[2]. There are also gauges for the measurement of suspended sediment concentration based on the measurement of natural y radiation from the suspended sediment [17], [18].

Transmission gauges

Nuclear gauges principle baseth absorptioe n d o radiatioth y f r eo o X knowe f nno ar s na

transmission gauges. With this typ f gaugeo possibl s i t ei measuro et intensite eth y Ia s? f wo radiation beam after being transmitted through water containing sediment, whose concentratio weighy nb bulr to k densitdeterminede b o t s yi intensite initiae Th . th f ylo beam, in the absence of water and sediment is Io > IS;W. e 2Ii Designatin Ry g S-b coun Wth o t^& rate s correspondin measuree th , 0 I I go s?d t d wan count rate afte monoenergetia r c electromagnetic bea mtransmittes i d f purthrougo em c hx water is given by:

Rw = Roexp(-uwpwx) (1)

where (iw and pw are, respectively, the mass attenuation coefficient (cm^/g) and the density (g/cnP purf )o e water. If the water contains sediment in suspension at a concentration C, the measured count rate wil: be l

(2)

53 where jxs is the mass attenuation coefficient of the sediment and pm is the density of the mixture water-sediment:

PsPw Pm = ————————— (3) Ps ' c(Ps • Pw)

where ps is the density of the sediment.

The determination of RQ is difficult under the experimental point of view and, for the calibration of the nuclear gauge, it is common practice to refer the count rate Rs w to Rw. Relating equations (2) and (1) one obtains:

) (4 } x w p w x[um u p mv(- + ] { - s C C) p —— l- ex -= Rw Substituting pm from equation (3) it follows that:

Mw w -P - s M s P Rs,w —— = exp - C (-——————) pw x} (5) RW Ps - c(Ps - Pw) r sedimenFo t concentration t largeno s r than SOOOOppm a hig, h design limir fo t suspended sediment concentration nuclear gauges secone th , d denominatoe terth mn i e th f ro equation represent neglectee b n s onlca d y relatio an n [19]3.1 i firse e % th on t , o nt t [20]I . follows that:

Rs,w Pw M- w ) (6 ——-—-- s (^ C x - w .....p )p ex .= s P RW Putting

————- s = x(P e >w obtains on P — ) : Ps

) (7 ) C S ( - p —ex — = Rw or

) (8 — —- —— = — n I C

S Rw Developing equation (7) in series and for small values of C, one obtains:

54 —- =1-SC or ————— = -SC (9) lw RW

In equation (9), being —————— = - S C, the slope S means the Rw sensitivit measuree th f yo .

s i directl S y proportiona e masth so t lattenuatio n coefficien f o sediment t (us) and to the source-detector distance (x). e masTh s attenuation coefficien sedimene th r fo t t increases wit decreasine hth e th n gi energ radiationy f yo . Emitters having electromagnetic radiation witenergyw hlo , suc: has 241 Am (y ray - 60keV) and lO^Qj (X ray - 22keV) are used in nuclear gauges, in order to increas sensitivite eth . yS In Figure 4.1 one can observe the variation in the parameter S PwHw - ———— s , e w (u wite electromagnetip th energ th h = ) f — o yA = — c x Ps

radiation. For energies above lOOkeV, S/x < 0.1 and the values of us and jaw are similar, decreasing the sensitivity and accuracy of measurements performed by a nuclear gauge. Relatively to the increase in sensitivity of nuclear gauges by increasing the source- detector distance relevano ,tw t aspects takehave b o ent into account:

givea r fo n ) activit a sourcee th f yo , fro mcertaia n source-detectoo rt distance du , eon the decrease of the radiation beam intensity caused by the absorption of radiation (photoelectric effect), one can reach a low count rate, insufficient for the statistical error (existing due to fluctuations in the count rate) to be within acceptable limits; ) increasinb g source-detector distances increases alsproportioe oth e scattereth f no d radiation by Compton effect reaching the detector with energy lower than that of the initial beam (build-up factor), resulting in a higher dependence of the mass attenuation coefficient on the chemical composition of the sediments [21], [18].

chemicae e effecth Th f o t l compositio sedimene th signae gauge f th th no f n s o ei lo t e utilizatiorelateth o t d f electromagnetio n c radiatioenergyw lo f o n, resultina n i g predominanc photoelectrie th f eo c effect [22], [23] thin I .s waychemicae th , l compositiof no the sediments can be expressed by the material parameter P:

n Zj5 P = S Pi——— (10)

where:

percentag= i P weigh y elemene b th f o t t existin sedimene th n gi t

55 0,01 C.)

(after Martin, I970-U83)

Figure 4.1 - Variation of the factor A= S/X related to the energy of the radiation

atomiZ= [ c numbe elemene th f ro t Aj = atomic mass of the element

t onle chemicaNo th y l compositio e sedimentth f o n s affect e accuracth e s th f o y measurements. Temperature and electronic drift are other important factors. If a gauge operate t temperaturea s s other than thos r s whicbeeefo ha nt hi calibrated t couli , d happen modification e mechanicath n i s l structur e gaugeth f o e, variation n watei s r densitd an y changes in the response of the scintillation detectors [24]. Another important factor affecting measurements is the change in salinity when nuclear gauges are operating in estuarine environments correctioA . n facto salinitr fo r y (83) mus takee b t n into accoun thin i t s cased an , equatio change) n(7 : sto

Rs,w = exp - (S C) exp - (S (11)

The influence of the chemical composition of sediments, based on quartzose-feldspathic sand d clays s studiean s wa , s founlaboratorn di wa t di distortiod yan r nfo arounL g/ d2 concentrations of 10 g/L in the case of 241 Am gauges, but almost zero distortion under the same conditions for 13?Cs gauges [25]. Taking into consideration all the effets mentioned before, it may be stated that measurements will be accurate to within 1 g/L for the 241 Am gauge, and within 2 g/L for the l^Cs gauge, for countings lasting for 10 minutes [26].

Scattering gauges

These gauges have a lead shield between the radioactive source and the detector. In this way. the radiations measured are only those scattered by the suspended sediments into the

56 volum influencf eo e relate gaugee th o dthit n .I s waysignae functioth a , densits e li th f nr o y o concentration of the mixture water-sediment. The functional relationship obtained experimentally by calibration of the source is:

Rs,w ) p a (- p ex n p) a ( = (12) MV e densitth wher s i r concentratio o y p e constant e ar n turbie th d sf dan o n watera d an , characterizing the gauges [27]. The scattering gauges are cilindrical and, in this way, they are suitable for measuring density of fine sediments deposited in reservoirs and to measure vertical gradient of sediment densities in the well of dredgers or barges, either by fall down or being introduced in tubes previously place measurine th source e 137t dd a th Ce an sgar sm sitescurrentlA 1 .24 y user dfo this type of gauge.

Natural radioactivity suspended sediment gauges

e measuremenTh f naturao t radiatioy l suspendee th f no d clay sediments (richen i r natural uraniu thoriud man m than siliceou r carbonato s e sediments s performei ) a y b d mechanical frame equipped only with a radiation detector and the electronic counting system associated. By means of a calibration curve it is possible to obtain values of the suspended sediment concentration from the measurement of the natural radioactivity [17]. applyinn I g thitakee b s o methont s intha o t di accoun influence th tdetectoe th n eo f o r the natural radioactivity coming from bottom sediments gauginr fo , g nea bottome e rth th d an , effect of cosmic rays when the measurements are made near the surface [17]. Furthermore, as

1,9 r *• * * * * B*

•» m 0.»

•v

c,« -

0 * S > 0 » W W 3 1 O « S 0 °*

(after Bondeiro and Aun, I989-120))

Figure 4.2 - Calibration curves obtained in laboratory using clays from river (cross) and estuary (points)

57 (A) •ir o t «trane«i t Suspension c»bl« v.nt Added »tight.

Radiation »ourct Support rvoinotor C.«.counter

(B) Suspension cable Added «eight An

»ire to Proportiona transmiL l t counter as aifnals t o!.e i , J981-1263(afteZh u L r ) detector

(C) Steel coble

Electricol cables Measuring volume \

\ \ 241 Depth sensor Ai- source Preamplifier \ NoHTII Cristal Photomultiplier

(afler Bandeira , 1992-[27]) Weigh)

(D)

(after Florkowsky, 1970-1223)

Gamma-ra- ) (C d Figur an - (A) ) y3 e(B transmissio,4. n gauges Gamma- ) (D ; - ray scattering gauge

58 0123 tifnt()>r»i >

IT'«-'»

0 1 : 3 timrlhr»1 S

(after Ross d Taziolioan , 1979-[303) Figur Rainfal- 4 e4. l histogram, suspended sediment concentration (C), water discharge and suspended sediment discharge (Cg)

the volume of influence for this type of gauge is much greater than that for gauges using artificial radioactive sources, it is advisable to make the measurements not so close ( < 1m ) to the bottom or the surface of the stream channel. These gauge e suitablsar r higefo h sediment concentrations (severa thir l fo sg/L d )an environmen e sensitivitth t d accurac e an measury th f o y s comparabli e e o thost eth f o e transmission gauges [27].

Calibration procedures

The calibratio suspendea f no d sediment nuclear gaug performes ei laboratoryn di , using sediment samples taken frostudiede sitb e mo eth t . Suspensions with increased concentrations are then created in tanks by stirring or pumping the mixture water-sediment. The measurement of the concentrations are made by the gravimetric method.

Plotting the ratio RS>W/RW (respectively count rates in the mixture water-sediment and clean i r water) agains measuree tth d concentratio eacf no h mixture obtaine on , calibratioe sth n curve (FIG. 4.2). This calibratio checkee b o t situ" n s d"i n ha , using samples taken durine gth interval measuremene th f so t campaign. Calibration procedures have to be carried out whenever significant changes in the chemical composition of the sediment have occurred. Variations in content of elements with high atomic number alte y materiae value th rth ma f , ,eo sucFe l s parameteha givea f o n P r sediment and the mass attenuation coefficient. In this way, it is advisable to perform the gauge calibration and also to determine the elemental sediment composition, in order to relate the calibration curve to the value of the material parameter P.

For instance, havin gcollectioa f calibrationo n correspondine curveth d san g valuef so materiae th l paramete givea r fo n portablP r e transmissionr gaugefo t possibls i i t e i , us o et different type sedimentsf so , without further calibratio laboratoryn i , provide value dth P f eo for each typ sedimenf eo knowns i t .

59 ON O

15- 150

O

«10-100

05- 50

0J 9 1 7 1 5 1 3 1 1 1 9 9 11 13 15 17 19 21

The dotted line (C) indicates data obtained in a section 0.05-0.25 m from the river bed; the continues line (C) indicates data obtained in a section between 0.020 and 0.60m fro rivee mth r bedsolie Th .d circles indicate data obtaine indey b d - pendent sampling, (after Tazioli, 1981-(243)

Figur Rainfal- 5 e4. l histogram, water stage (IIsuspended )an d sediment concentration gaugem A 1 different registeresa 24 o tw ty db depths . Uses of nuclear gauges and some results

beginnine pointeth s n A i t thif dou go s chapter maio , thertw ne fieldear applicatiof so n for nuclear gauges using artificial radioisotopes. The "in-situ" measurement of high concentrations above 0.5-l.Og/L up to 100g/L of suspended sediment (sand, clay)d siltan , which occurs tim e mos th torrentia n ef i o t l riverr so in flood seasons in some rivers, may be performed by means of manned gauges, allowing the vertical profilin concentrationf go usinr so g fixed gauges continuour fo , s unattended recording of concentratio r alternativelno r measurinyfo g sediment concentration only during flash floods. In the latter case, the gauge is activated by a switch when a pre-selected water level is reache turnes i d ddan off whe levee nth l falls.

10*

JAN* _ s •*• APR

O 2 MA •MAR O JO* •MA MAR

NOV Q » 0 • O APR

b. * APR [•JAN»?' 10' APR NOV JAN',*,* s • MAY •MAY NOV»

JUN< *F£B i- MAY* APR. lo1-

MAY 5-

3 . 4 1C ' * i JO i S I ' * S JO' FLOOD VOLUME (m'j

(after Tazioli et al , 1987-[32])

Figur Relationshi- 6 e4. p between total suspended sediment transpor totad an tl runoff floofo5 r2 d events.

61 Measurement of suspended sediment concentration

Applicatio mannef no d nuclear gauge bees sha n performe Chinn di a since 1971 [28]r fo , the measuremen f suspendeo t d sediment concentratio e Yelloth n ni w river. Transmission gauges where develope thir dfo s purpose radioactivd an , e sources with activitiesi mC 0 20 : (7.4 GBq) of 137Cs and lOOmCi (3.7 GBq) to ICi (37 GBq) of 241Am have been used. In Figure 4.3, some examples of transmission and scattering nuclear gauges are shown. Fixed transmission nuclear gauges have been intensively used in some selected hydrographie basins in Italy, since the seventies, for measuring suspended sediment concentrations. Two basins in southern Italy: in Basilicata (area of 63.5 km ) and in Calabria 2 (area of 4.7 km2) were studied with the following objectives: a) observing the phenomena of erosion and solid transport during flash floods hi which high suspended concentrations occur; b) test different type nucleaf so r gauge theid san r functioning under severe conditions [30], [24], [26], [2]. These basin characterizee sar torrentiay db l regime surfacf so e runoff. Some result Torrentf so e Ilice basi Calabrin i showe ar a Figurn i e 4.4. This basis ni underlai crystalliny nb e Paleozoi Quaternary cb rocd kan y sanconglomerated dan s which provid largea suspended ean amound be df o tmateria transporr fo l resulta [31]s e A th t. suspended sediment is mainly sand. The measurements performed with the fixed nuclear gauge using ^7cs showed suspended sediment concentration values d highean L rg/ tha0 n10 the basin does not present any relationship between runoff and suspended sediment concentration [2]. For Torrente la Canala basin, in Basilicata, characterized by Quaternary marly clays of generally silty and/or sandy texture, quartzose-calcareous sands and by polygenic

.PRESSURE SENSOR

SCINTILLATION —INCLINOMETER DETECTOR

o o .SEALED SOURCE COLLIMATOR- OF 24lAm

BALLAST.

V V (after Solim et öl.,1983-133])

Figure 4.7. Densit- a y gauge principlbasee th n do gammf eo a radiation transmission

62 PRESSURE SENSOR

SCINTILLATION DETECTOR SHIELD

RADIOACTIVE BALLAST SOURCE

(after , 1983-[34]MeyeI. a i e r )

Figure 4.7.b Backscatterin- g nuclear gauge (Sapra JTD3)

conglomerates, results obtaine transmissiom A 1 d24 wito nhtw gauges, fixe t differena d t height d showes be fro e mdth that, during major flood events ,appreciablo n ther e ar e e gradients of suspended sediment concentration, as shown in Figure 4.5 [24], [26], [2]. This findin explaines gi predominane th y db t cla sand-silr yo t natursedimene th f eo t thia t s basin. e meaTh n annual suspended sediment load exceeds 100 loa0d t/kmdbe transpord ^an s i t despicable. Torrent a Canall e a basin show a goos d degre f correlatioeo n between total runoff volume totad san l suspended sediment load somr sfo e flood events shows a , Figurn i e 4.6. An automatic 241 Am source transmission gauge, which can be moved vertically along steel rails profilinr fo , verticae gth l gradient f suspendeso d sediments installes e wa , on t da statio basie th Muson f nn o i e river, near Ascona city centran ,i l Italy. This surfacbasia s nha e area of 640 km^ and an experimental study is being carried out for monitoring flood processes by controlling all the hydrological, sedimentological and morphological parameters involved, in order to have a global description of flash fluvial phenomena [2]. The information provided by this nuclear gauge together with periodic topographical survey f riveso r cross-sections, rainfal wated an l r stage recordings, river flow measurements and bed-load monitorin contributes gha bettea do t r understandin principae th f go l phenomena of erosion and sediment transport. It was also demonstrated that the suspended sediment transport typically anticipates the peak of liquid discharge and that there is a strong correlation between total suspended sediment transport with total runoff volum eacf eo h flood.

63 Kccldc*ranc*

Dcntity

M»u6c*J depth

X N- r 1 *}____ LOOM tilt * vv — — — — — ——— ContoiidAtttf tilt "•——————-*• Consolidated bonom

(after Caillot et aI., 1984-135)) Figure 4.7.c - Scheme of keelclearance

Measurement of bulk density of fine sediments deposited in reservoirs and in coastal environments

One important parameter for the sedimentological balance of the system: lake catchment basin-reservoi measuremene th s i r quantite th f o t y (mass f sedimento ) s deposited inte oth reservoir, durin gcertaia n time interval meany B . echf so o sounding surveys, performee th t da beginning and end of the considered time interval, it is possible to calculate the variation in volum reservoire th f eo , referre certaia o dt n reference level. regioe th n nI wher rivee eth r enter reservoire sth , wher depositioe eth coarsee th f no r (sandy) sediments occurs, a vertical density gradient does not exist. The mass of deposited sediments can be calculated, considering the variation in volume given by echosounder surveys and the uniform density of the coarse sediment deposited. By the way, in the region of preferential deposition of the fine sediment (silt and clay), nearer the reservoir dam, it exists a vertical density gradient, not well determined by echo sounding surveys, even by using simultaneously equipment of low (33 kHz) or high (210 kHz) frequencies having, respectively, high and low penetration capacity. To overcome this limitation, twin-prong transmission and single-prong scattering nuclear gauge usee sar d (FIG. 4.7b)d 4.7an a . These gauge normalle sar y equipped with depth sensors and inclinometers for the underwater unit. They are used as point measuring systems and are lowered on a suspension cable to sink into the soft bed by falling down under its own weight. In this way, density profiles between 1.0 and 1.5 g/cm^ may be determined. As the scattering gauges are cilindrical, they are also suitable for being introduced in tubes previously placemeasurine th t da g sites, allowin extenden ga d rang valuee f eo th r sfo density profiles. 241 Am and 137cs 3^ me sources currently used for this type of gauge. In harbours submitted to heavy fine sediment siltation, such as Rotterdam and Zeebrugge, in Europe, and in some harbours in South America and Indonesia, it exists in certain parts, a lower density layer above the more consolidated bed sediment, named fluid mud, which can attain several metres. The top interface between the fluid mud layer and the

64 water above is generally detected by the echosounder of 210 kHz frequency, normally employed for surveying nautical depths. It was demonstrated by ship manoeuvering and laboratory obstacl n studiea t navigationno o e t ss i tha fluid e tth dmu , provide buls dit k density g/cm2 equas i 1. r leso o ^t l s (FIG. 4.7c) thin I . s way, sinc late eth e seventies, radioactive gauges have been operated at spot locations in Rotterdam waterway, hi conjunction with echo sounding surveys produce th s thif A .o t s survey, nautical charts showin g/cm2 1. e 3gth density depth contour preparee sar used navigatior dan d fo dredgind nan g work purposes. harbourn I s where large area shoulfluif d so dsurveyedmu e db t seemei , d interestino gt perfor mcontinuoua s measuremen f densito t y instea f measurementdo t sposa t locationsi h , this way towea , d density prob developes ewa d overal e [36]Th . l system fisconsistw hto a f so containing a ^^Cs transmission gauge and a depth sensor, an "intelligent" winch controlling verticae th l movemen fis e orden hi th g/cm f 2 folloo o tr1. t e 3w th pre-selecte d bulk density an dmaia n computer which control necessare runsd th a san ,vi y interfaces simultaneoue th , s echo soundin densitd gan y surveys. This typ equipmenf eo coste b y -expensivs i t ma t i d ean effective only in the context of large area repetitive density surveys. Another importan nucleaf o e tus r gauges relateimprovine th o dt dredginf go g works si the measuring of density profiles of dredged spoil in the well of dredgers, allowing to evaluate loae th d efficienc particulaa f o y r dredging practice examplen a s A .Figur e th , show8 e4. sa schematic dredging cycle fo trailinra g suction hopper dredger. Loading curve dredgere th f so ,

Ton.

40%

% (PERCENTAG20 SANDF EO )

Time

TRAVED LAN DUMPING TIME

OPTIMUM DREDGING CYCLE

t- ,Star t dredging time - Star j t t overflow time

ts - Optimum dredging time

Figur Dredgin- 8 e4. g cycl trailina r efo g suction hopper dredger

65 0\

mapy FigurKe ,estuar - d Santo1 an e5. y ysba tu too moto

Dt TSÇ / ,....-—•—•/.07/OZ.

\\»«** .;-'"V.> ^v'-^ ..:\>.mlA l •'••' &f*' -^.

LIMIT OF TMC ftttlOM CONTAIN»«) 100%r O

— ——LIMI ftt*IOC TH Nr TO CONTAININ f SANO D% 50 «

S«NO • tOO\90< % 9AND< IOO\ % SAND « SO \ \ \

(after Bandeir , 1981-1351 . öl t ae ) IM 00«

Figure 5.2 - Santos bay: tracer injection points (PI), wave gauges (W) and recording currentmeters (C) at measuring points (MP) - Clouds near PI are related to the last complete detection performed accordin percentage th go t sanf eo d dredged (relate totae th ldo t amoun sandf to , clay) d siltan , are drawn fixea r d. Fo trave dumpind lan g time (same dredged regio samd nan e dumping site), aneacr dfo h loading curve, theroptimun a s ei m tim dredginr efo g with overflo t2)- 3 ,wn i (1 order to get the optimum dredging cycle time (tangent to the specific loading curve).

CASE STUDIES

Santo [37y sBa ]

The shape of Santos Bay, in Säo Paulo State, Brazil, 60 km far from Säo Paulo city, is roughly quadrangular, limited at E and W by two rocky points, Ponta Grossa and Ponta de Itaipu (FIG. 5.1), with an area of about 36 km^. Two estuaries, Santos at E, and Säo Vicente at W open into the bay, the contribution of Santos estuary to the overall flow in the bay being more important. The most important Brazilian port facilities are installed at Santos estuary. Adequate depthe harbou th e kep t ar accesd sa tan r s channel through permanent maintenanc eimportance dredgingth o t e f SantoDu .eo s harbour, several sedimentological studies were performed at Santos bay and surroundings, from 1973 to 1985, using a combination of hydraulic measurements, physical movable bed models and radioactive tracer studies. Bottom sediments in the bay cover all the range between fine sand and clay (FIG. 5.2). The material dredged in the harbour is mainly silt and clay and in the access channel it includes also fine sand. Studies performed in 1973/74 [38] had the objective of evaluating various dumping sites to reduce the distance from the dredging region to the disposal areas. In the first study it was determined labelliny b , fule gth l loa bargef do s with 198AU, thadisposae th t l area near Ponta de Itaipu, at W, was inadequate, since the material could return, by the action of hydrodynamic circulation bay-estuare th o ,t y system (FIG alternativ. w 5.1)ne .A e site outside s chose wa baye , nth E t nea,a r Moela island uses It . , implemented immediately aftee th r studies, resulte sensibla n di e reductio maintenancn no e dredging costs. In 1985, another dumping site, also entrance y eastwarba e th o d,t near Ponta Rasa rocky point was defined (FIG. 5.1), with the objective of reducing, even more, the transportation distances [39]. Again, the technique used was the labelling with 198AU of the dredged material transported by barges. The new dumping site has been used since 1986. Hydraulic measurements and tracer studies performed in 1980/81 [40], using ground glass labelled with l^li, were intende defino dt behavioue th e bottoe th f mo r fine sandy sediment tha founs i t somn di e region baye behalth n f o , s o modef fo l studies. Six injections were performed in different regions of Santos bay; three in the winter of summe198e thred th an 0n e i 198f ro 1 (FIG. 5.2). Befor injectione eth summern si bottoe ,th m was surveyed in order to detect the remaining of the radioactive clouds from the winter experiments stils lwa possiblt I . fino et d activitie morf o s e than twic backgrounde eth e th n i , regions inside the dotted lines, having origin in Pl\ WINTER an^ ^3 WINTER- ^ ^s way summee th , r tracer injections were made outside these regions. Both in summer and winter, bottom sediment movement has an onshore resultant, being more importan winten i t r conditions. Transportation rates were quantifie botn i d h regimes (Table I). Waves, associated with tidal currents inside the bay, are the main transport agents, the direction of movement being always compatible with the prevailing waves incidence directions (FIG. 5.3).

68 MP3/Winter (Fig.5.2» TIME INTERVAL: O8/08/80 TO 27/09/80

MP3/Summer (Fig.5.2) TIME INTERVAL: 14/02/81 TO 09/04/81

(After Bondeiro el al.,l98l-{35]}

Figure 5.3 - Wave direction frequency

69 1,0m ABOVE BOTTOM

-^^\

s« 1 o.._ T _._rf __f /L is »

17 (öfter Sondotécmco,I977-136)) KEYS

ÄVERftOE RESIDUAL VELOCIT Y- CURREN T METE R• SONOOTÉCNIC 4 CAMPAIG /JUN ) JA Nl 76

MAXIMAL INSTANTANEOUS VELOCIT Y- INP H CAMPAIGN (OCT 72/JUNT3)

MOST FREQUENT AVERAGE DIRECTION-RECORDING CURRENT METER-SONDOT CAMPAIGN (NOV T5/OC1 T76

MOST FREQUENT AVERAGE DIRECTION - INPH CAMPAIGN (DEC 72/AUG 7SI

INDICATIVE VECTOFLOE TH WF RO DIRECTIO N

s SPRING TIDE -x^ r 0 NEAP TIDE

~L^f 1*2 CURRENT METER GAUGING SPO T• SONOOTÉCNIC A CAMPAIGN

's " CURRENT METER GAUGING SPO T- INP H CAMPAIGN » RECORDING CURRENT METER GAUGING SPO T- SONOOTÉCNIC A CAMPAIGN

RECORDING CURRENT METER GAUGING SPOT- INPH CAMPAIGN

0 19 0 10 0 5 tooo TOOO SCALFS - I • ——I—— V[\.OCITIC9 Itm/» I OISTtNCCSIn)

Figur eHydrauli- 5.4.a c circulatio Santoe Floo- th y n ni s ba d phase alss Iowa t determined that, attaineds whei depte m n7 th f ho , bottom material under movement tend infleco st t towards Santos estuary entranc seto f stw o e indicates eth a e th y db dotted lines (having injectioorigie th n i n performe 03/08/8t da \ WINTER)Pl n 0i » fr° detections dated 07/02/8 08/04/8d 1an 1 (FIG. 5.2) alss i t o.I possibl observo et e mm e froe mth successive position thesf so e dotted unes movemene th , bottoe th f mo t sediment towarde sth coas alsd osmalletan a r shift westere towardth f o nsW portio linee th f sn o limitin activitn ga y equa twico lt naturae eth l bottom sand background. The current circulation pattern inside the bay, mainly tidal influenced, was determined by intensive field measurements employing manned and recording currentmeters [41]. Figures 5.4a and 5.4b show, respectively, the current circulation for flood tideanb dthret eb s a e level belom s(1 w surface abovm 1 deptd bottom) e d emi th , han s i t I . interesting to observe that, for the eastern part of the bay, where the injections Pl£ WINTER anSUMME2 dPl R were performed currente th , alwaytidee b sar eb floo) n d directes(i dan o dt

TABL - Mai EI n results obtained with sandy bottom sediment transport studien i s Santos Bay using ground glass labelled with

Injection Time Depth Related Bottom Azimuth of the Points Interval to Sediment Sediment (FIG. 5.2) Considered Hydrographie Transport Transport Cloud Datum Rate Axis (m) (kg/m/day) 03/08/80 l WINTEPI R to 7.9 270 342° 22/09/80 08/08/80 PI2 WINTER to 12.3 350 335° 18/09/80 06/08/80 PI3 WINTER to 10.0 200 14° 19/09/80 09/02/81 PIl SUMMER to 7.6 10 350° 08/04/81 08/04/81 to 20 350° 20/06/81 21/02/81 Pl2 SUMMER to 10.9 40 339° 07/04/81 07/04/81 to 40 339° 19/06/81 19/02/81 PI3 SUMMER to 9.3 10 349° 02/04/81

71 to 1,0m BELOW SURFACE 1,0m ABOVE BOTTOM

H'00'1 ————

(after Sondotecmco, 1977-136)). KEYS »- AVEHAOE RESIDUAL VELOCITY -CURRENT METER- SONOOTÉCNICA CAMPAIGN (JAN /JUN 76) 1> MAXIMAL INSTANTANEOUS VELOCITY - INPH CAMPAIGN IOCT 72/JUN Til • > MOST FREQUENT AVERAGE DIRECTION RFCORDINO CURRENT METER SONOO• T CAMPAIGN (NOV 75/OC) T76 \. *• MOST FREQUENT AVERAGE DIRECTION - INPH CAMPAIGN (DEC 7Î/AUG 731 r~~ l «Nl, ^ INDICATIVE FLOE VECTOTH W F DIRECTIORO N S SPRING TIDE V 0 NEAP TIDE A~>^ 12 CURRENT METER GAUGING SPO T- SONDOTECNIC A CAMPAIGN -i^fV- i T, H ~c; ————————————— h;-\ : :»/ - t i CURRENT METER GAUGING SPO T- INP H CAMPAIGN '^"-^ m « RECORDING CURRENT METER GAUGING SPOT- SONDOTECNICA CAMPAIGN 0 RECORDING CURRENT METER GAUGING SPO T- INP H CAMPAIGN ^f 'V* "- ( •i* '^a v «,-i ^i„-5*.at, «0 100 I» » KX !OOO XXX) •S^ SCALES :V VUOCITItS (cm/I I OISUHCCSInl Figure 5.4.b - Hydraulic circulation in the Santos bay - Ebb phase , flowinN g toward interiocounterclockwise a baye sth o t . th e f Thiro du s si e circulation inside the bay, during ebb flow. As a consequence, in spite of the greater depths relatively to the other regions, the bottom sediment transport rate for the eastern region is also higher, both in winter and summer regimes (tabl . ThieI) s t findinreasoe coulth no r e db ngfo remaining activitiee th i sh region of Pl2 WINTER radioactive injection, before the injection performed in summer time. From this case study it is possible to evaluate how powerful radioactive tracers can be in answering bottom and suspended sediment movement questions, provided a good knowledge of the hydrodynamic conditions of the site under study is available.

Alumar Harbour [37]

Alumar harbour (FIG. 5.5) has been built to serve a huge aluminum factory near Sâo Luis city, capita Maranhaf lo o Statenorte th Brazilf hn o ,i accese Th . s channe Estreitn i l s odo Coqueiros, linkin terminae Marcogo th Sâ o t turninlse Bayth , gberthine th basi d nan g area were dredge regioa n di n betwee islandso ntw : Tau Luisa o current e MiriSâ e Th . d th m an n si regio mainle nar y tidal influence reacn ca hd valuedan s above 2.0m/s during spring tidese .Th tid semi-diurnas ei l presenting spring tidal amplitud f aboueo naturae t 7.0mTh . l sediment encountere bottoMarcoe o mainls th i Sä n dy i mf o s Ba y sand. hige Duth ho et natura l suspended sediment concentration (abou mg/L)0 60 t , being silt and clay its main constituent, a strong sedimentation occurs in the dredged regions. In this way, the dredged material is mainly silt and clay, except when certain parts of the access channel , dredged Marcoe neareo ar Sä y o rt s Ba . Adequate natural depth kepe sar t thi y a t sba hige th ho t tida e ldu currents, being that plac naturae eth l dumpin e disposagth sitr efo f o l dredged material. In order to improve dredging works, various studies employing nuclear techniques, together with hydraulic measurements were performed. Labelling full charges of a trailing suction hopper dredge d dumpinan r e materiao Marcogth Sä showey n i Ba ls d thae th t conditions for the dispersion of dredged material, dumped into that bay, were very favourable [42]. Very fin e littlth e f materiaeo l discharge dredgee th y db r remain sande th n yso bottomt a e sitf disposalth o e , being resuspende e higth hy b dspee d currents. Besides thate th , concentration of the discharged particulates remaining in suspension soon reaches the concentration level naturally presen baye .th n Consequentlyti chosee ,th n disposal area could be changed to a site closer to the entrance of Estreito dos Coqueiros, care being taken to avoid disposal shortly before or after tide reversal, while currents are not strong enough. Other studies were madharboue th t ea r regio attempn a n n [43i implan]o t t some sorf to agitation dredgin thin gi s area wher sedimene eth t depositio quits ni e important thin I . s case, dredgee th fate f th eo d spoil depend positioe dischargth e n th s o f no e stage eth th f sitd eo ean tide. During flood tid suspendee eth d materia carries li d eithestretc e Estreite th th o f rt h s o odo Coqueiro Cachorross do so harbousoute Ri th o f t h, o r whicro h openharboue th n si r region, and most of it settles down to the bottom. When the dumping is performed during ebb tide, the position of the discharge site makes a great difference. Tests were made near the western eastere th d nan extremit harboue th f yo r terminal trajectoriee Th . sedimene th f so quite ar t e different in both cases, but the material tends to move to sites of preferential sedimentation. When discharg dons ei e throug pipelinha e fro msuctioa n dredger operating neae th r berth, a considerable part of the dredged spoil sinks directly to the bottom due to the influence

73 n Wt 6 4 0 3 0 2 o t O

•- TSTADO DO MARANKAO

(Aller Moreir Bondeirod on o , 1984 - 138] )

Aluma- p ma ry harbouFigurKe - 5 e5. r

74 of the initial downwards momentum and negative buoyancy of the slurry jet. If the discharge is made parallel and just below to the surface water, the slurry remains in suspension for long times (FIG. 5.6b)5.6d an a . Sinc tidae eth l stagutmosf o s ei t importanc behavioue th r efo f ro the dredged spoil which remains in suspension after the disposal, much can be gained in terms abatemenf o sedimentatiof o t berthine th turnine n i th gn i aregd basiaan matchiny nb e gth discharge regim tidae th l eo stagest . Six suspended sediment injections (Tablfinf o e) emateriaII l labelled Awit8 U h19 wer e performed in different points of the Estreito dos Coqueiros and the harbour turning basin (FIG. 5.7), discharging the labelled material into the jet of a suction dredger (injections 3 and 4directlyr )o , paralle jusd tan l beloe th wate e wo th t re surfacDu . 6) e d (injectionan 5 , 2 , 1 s small depths in some parts of the studied region, two scintillation detectors were placed at one metre below the water surface, in a rigid pole fixed to the detection boat. It was possible to compute the advection velocity (u), the longitudinal (D]_) and transversal (Dj) dispersion, the dilution, the sedimentation rate (SR), the necessary time for the sedimentation of half of the cloud (Tj/2) and Lj/2 = u.Tj/2, for all the experiments. Table n presents the results of some thesf o e parameters, wher dispersioe eth n value calculatee sar T\/2e th r dinstantfo . It can be inferred from Table II and Figure 5.7 that the higher sedimentation rates correspond to injections (3 and 6) being performed in situation of ebb flow, in the sheltered regioturnine th f no g basin , flob relativeleb w e cominth o yt g fro southere mth n reacf ho Estreito dos Coqueiros. For this situation, in this region, there is the composition of the ebb flows coming from Rio dos Cachorros and from the southern reach of Estreito dos Coqueiros, producing a gyre of the cloud from an E-W movement to a S-N one, in a kind of vortex, facilitating the sedimentation. Furthermore, the third injection was performed into the jet of suctioe th n dredger operatin berthine th n gi g area.

TABL - Mai EI I n result suspendef so d sediment transport studie Aluman si r Harbour region using mud labelled with

Average Longitudi Transversal Sedimen- Inj Gauge Tidal ampl Advect naldisper- dispersion tation rate Lj/2 Tl/2 ecti (m) velocity sion(m2/s) (m2/s) (g/ton/s) (m) (min) on and stage (m/s) No. 1 1 6.6 0.75 2.15 0.23 431 896 20 2 ebb 2.76 0.18 361 1069 24 2 1 5.8 0.22-0.63 0.88 0.28 532 290 22 2 flood/ ebb 0.30 306 449 34 *> 1 3.9 0.32 0.19 0.11 2289 94 5 2 ebb 0.10 0.10 2257 95 5 4 1 3.2 0.38 3.27 233 1123 50 flood 5 1 3.4 0.55 1.10 1.12 449 794 26 2 ebb 2.89 3.43 371 961 31 6 1 5.4 0.08-0.28 0.53 917 68 13 ebb/ flood

75 Current measurements made durin raine gth y season [44] showe existance dth a f eo null-drift point in the lower water layer in the vicinity of the harbour, at spring tides, which strongly enhances sedimentation. This is unlikely to occur during dry seasons since fresh- water contributio systee th that n o ma t vers i t w timeylo . Another field experiment performed in Estreito dos Coqueiros had as objective to study the contributio sande th f yno bottom sediment transpor accese tth froMarcoo o t sm Sä y Ba s channel. Ground glass labelled with 198 AU was injected hi the northern extremity of the access channel. The diameters of the grains were comprised between d 0.177mman 0.12m m 5, representin naturae gth l grain size distributio e bottoth f mo n sediment. Governed by the strong tidal currents,the bottom sediment transport hi the access channe bi-directionals i l , wit hresultana (1.E 2SS t/(m.d)o t harboue th n i , r direction (FIG. 5.8)surve e radioactive pointeth s th ,a y f yb o t dou e cloud durin days0 g1 , covering sprind gan neap tides [45]. "In-situ" density measurements using a nuclear transmission gauge developed in Brazil allowe evaluation da bule thicknese th th k o layefluif d e t ndensito th 3 p dmu f u r1. so f yo g/cnP [33]. The variations in this thickness clearly showed a preferential Sedimentation hi the turning basin and a still stronger tendency to deposition in the berthing area, halfway from its centre, toward easters sit n extremity. These measurement beine sar g performe monthla n di y basis, since 1983 controo t , l depth variation optimizo t d san e dredging operation t Alumasa r harbour.

Stud Ivaf yo i Rive Tributaried ran s [46]

This wor bees kha n previously performes reporte wa r grou t i ] butou d ds [2 py an a ,d b presents some important characteristics agais i t ,i n reviewed. The northwestern regio f Paranno a State undertoo krapia d proces f deforestatioo s n during the development boom that occured at the region, causing severe problems of soil erosion. The region belongs to River Parana basin, one of the most important rivers of South America that contributes to the formation of Rio de la Plata. One of the tributaries of River Parana that drain the area under study is River Ivai, 650 km long and an average discharge of about 800 m^/s, at the measuring station. Studies have been performed to study the annual sediment discharge of Rio Ivai and of four of its tributaries, selected in function of being representative of a particular soil type or land utilization. The objectiv measuro t s bed-loaewa e eth d transpor Rivef to rrelativel a Iva r fo i y short those perious ed resultdan evaluato st applicabilite eth severaf yo l hydraulic equations useo dt calculate sediment discharge from conventional flow parameters. The studies at the small stream had the objective of the direct determination of their sediment discharg responsn ei locao et l catchment circumstances. Fowore rth Rivet ka r Ivai, whic abous hi t 200m wide speciaa , l platfor prepares mwa d to perform the injection and detection of radioactive tracer and to serve as a basis for conventional measurements. Fine sand labelled with l^A ur simulateo iridiuy db m glass swa used in the experiments.

76 CUCTION DWCO4CR CL«OW

LMtLUT OJE

(After Moreir Bondeira,l984-[38)d an a )

Figure 5.6. aSketc- setue traceth r f phfo o r injectio dredgee th n i t rje

N A

Q) LABELLING OF THE DREDGER JET ) INJECTIO(? LABELLEF NO A P D DMU RALLEL AND JUST BELOW TO THE WATER SURFACE P.I.-INJECTION POINT

Figure 5.6.b - Behaviour of fine sediment dumped in ebb phase

77 •n ooo •71000

OBSERVATION : THE LINES WITH ORIGIN IN THE INJECTION POINTS ARE THE LIMITS OF THE DETECTED SUSPENDED SEDIMENT CLOUDS \_t 6th INJECTION

6TIOOO

Figure Injectio- 7 5. n point suspendef so d sediment labelled with For the small creeks, activities used amounted to 5.5 GBq (150 mCi) of 198AU and 2.6 mCi0 mai 16 e 192f )o th o t Irnt 9 river.A (6 q , theGB y9 5. hav o t e been (6022.q 20GB mCi) and 10.2 GBq (275 mCi) respectively. Surveys of the longitudinal distribution of the tracer were performed using a sledge pulled from the platform at River Ivai. For the small creeks, detectors were fixed to a trolley that coul movee db t constanda t speed, along rails erectebankse th e coun n Th do . t rate balance method was used for all the experiments. The comparison between direct measurement Rivet sa r Ivathosd ian e compute fivr dfo e semi-empirical equations have shown considerable differences f theo mo werTw . e chosen since they represented quite wel resulte lth fielf so d experiments (FIG. 5.9).

The experiments of the creeks were also quantified and relationships have been stablished between their solid discharg regioe th d n ethaan t they drained.

( after Bomtemp l al.oe , 1984 (403- )

Figure.5. 8Injectio- n point (04/05/84)I P : ; center gravitf sradioactivo e th f yo e bottom

sediment clouds: CG2 (07/05/84), CG4 (14/05/84); and limit of the radioactive cloud (14/05/84)

79 Sedimentological Studies in San Diego River Basin and La Juventud Reservoir - Cuba Using Nuclear Techniques [47,48]

San Diego river basin (FIG. 5.10 situates )i westere th n di n par Cubf o t a Island t souta , h of the Cordillera de los Organos, and has an area of 254 km^, up to the La Juventud dam. Works performed in this basin, under the IAEA Technical Co-operation Project CUB/8/009, had the main purpose of introducing in Cuba the use of nuclear techniques as a tool for solving some sedimentological problems. The following objectives [47,48] were pursued:

•Measuremen e th densit d thicknesan f o y tf o layer sf o sedimens t e depositebottoth f o n reservoirsmo d , using backscattering density gauges; •Measurement of the concentration of suspended sediment transported by water courses applying, when indicated, y-ray transmission gauges; •Investigat e th origi f eo sedimentn s basen o theid r lithologicad an l chemical composition, using methods of X-ray diffractometry analysis, X-ray fluorescence and neutron activation analysis.

r measurinFo e densitgth thicknesd yan f layero s f depositeo s da L sedimen e th n i t Juventud reservoir speciaa , l floating platfor constructes mwa d (FIG. 5.11) equippes i t .I d with outboaro tw d motors centraa , l structure havin towega r from which acces- y se tubeth r sfo backscattering density gauges are driven to the reservoir bottom, with the help of a harnmer.The floating platform is also adequate to be used in bathymétrie surveys of the reservoirdimensions it easilo e t b e n y.Du ca transportet si trucy db otheko t r reservoirs. Figure 5.12 shows density profiles obtained at ?2 and ?3 points (FIG. 5.10), situated, respectively, outside and in the position occupied by the former thalweg of the San Diego river hi the region of La Juventud reservoir. It can be seen that the thickness of the layer of the fine deposited materia 0.5s i l 2.5md man , respectively alss point3 ? or wa performet i Fo ., da y-logging, which also indicate interface dth e water-sediment (FIG. 5.12). It was planned to use a y-ray transmission gauge at the hydro-sedimentometric station Los Gavilanes Diegn , situateSa oe riveth n di r (FIG. 10). Bottom sediment samplea Juventue riverL th n Diegoe f Sa th so sa Juli d L , an a reservoir were taken in the points shown in Figure 5.10 and submitted to X-ray diffraction analysis, X-ray fluorescence and neutron activation analysis, in order investigate the origin of the sediments related to its possible sources in the hydrographie basin.

Sedimentological Studies in Magdalena River, Barranquilla - Colombia, Using Nuclear Techniques [50,51,52]

Magdalene Th a mai e riveth ns i r water cours Colombiaf eo hydrographis It . e basis nha an are f 250,00ao 0 km^ s lengt^it s averag it s 1,50hi ; 0km e flow rat 7,00s ei 0s it m^/ d san estimated total sediment transpor 172*10s i t ^ t/a, considering measurements performed near its mouth [49]. The access channel to the harbour situated in Barranquilla ("Terminal Publico" maintaines i ) dredgingy db , mainlreace th hn y i jus t rivee soutth rf ho island f o s sector Siape (FIG. 5.13). The reason for the preferential accretion in this region, in which there is no flow inversion, is that the channel crosses the river from the left to the right bank

80 E I c o

o*0> t_ n _jo

•o ~o

OJ >

fD

E

! M l l ! l ! l t l l l l l l M, 16 18 20 22 24 26 28 30 2 A 6 8 10 April/I975 May/1975

(After Wilso al.t e . , n197Jr 9- [41] )

materiad Be Figur - 9 l edischarg5. e estimated from standard equations compared with tracer results - Rio Ivai

and thus the flow velocity and the sediment transport occur transversely to the channel alignment. Furthennore, ther graduaa s ei l increas rivee th rn e i sectio n from sout norto ht n hi this region and hence the average flow velocity decreases, facilitating the sediment deposition channee inth l [50,51]. Maintenance dredging in this curved reach of the access channel is performed by a trailing suction hopper dredger ("Boca Ceniza")e sd , with carrying capacitd f 5,00yan o , 3 0m amounts, presently 5*10o t , 6 m3/a. Afte constructioe th r trainina f no g positio e wallth n i , n occupied by the present curved reach of the channel (FIG. 5.13), the maintenance dredging in this reach is expected to decrease to 1*10 m /a [52]. Nevertheless, it will be necessary to 6 3 dredge the new channel, besides and parallel to the training wall, in a region of a mud bank. This capital dredging, estimated in 6*106 m3, is foreseen for 1994.

81 oo K)

CAVILANCS PUENTE SAN DIEGO JULIUNIOA L É AND Y SAN DIEGO CAIGUAN'ABO ARRIBA CAIGUANABO ABAJO

CAIGUANABO MEDIO

- SAMPLIN • G OF BOTTOM SEDIMENT X - DENSITY MEASUREMENT POINTS (After Bandeira , 1990/1991 - [42,43]) EMBALS' E2 EMBALS' 3 E EMBALSE 4'

Figure 5.10 Diegn Sa - o rive Juventura basiL d nan d reservoir •420- 0 0 ACCESS TUBES PLACE

BUOYS BUOYS DRAWING AREA FOR THE TABLE NAVIGATOR

MOTOR

AREA FOR THE PILOT WINCH SOW-T

MOTOR ... j ANCHOR{ U / / S

WINCH PISTON CORE ANO OAMMA-BACK- K-300

SCATTERINO OENSITV PR08E D 0

(After Bandeiro ,1991-

oo U) Figure 5.1 1Layou- floatin e th f to g platform POINT P2 POINT P3 POINT P3

DENSITY (g/cm3) DENSITY (g/cm3) GAMM (cpsG ALO ) 0.00 1.00 2.000.00 1.00 2.00 0 6 12 18 24 30

5- 5- 5-

- -

I 10- x 10- t- a a a UJ UJ o o ë \

15- 15- 15-

20-1 20-J 20-1

(After Bandeira, 199 1- [43] )

Figure 5.12 - La Juventud reservoir density profiles

The dredged material, ranges from clay and silt to medium sand, the finer material occuring mainly durin watew glo r season (Januar Aprio yt - FIGl . 5.14), whe floe nth w velocities near the bottom are also lower and there is the presence of a salt wedge in the region, facilitating the deposition of the finer material. The present dumping site is situated outside the Magdalena river mouth, as indicated in Figure 5.13. Studie beine sar g performe orden di verifdredgee o rt th f yi d materia dumpee b n ca ln d i the proposed s Floresite La n froni ,f so t (FIG. 5.13). This t regiosubmitteno s i n o t d maintenance dredgin naturae th d glan bottom sedimen almoss i t same th t thas ea t foune th n di

84 (Afler Bondeira , 1991 - (511)

^

COAC D . MALUONOUIN

pnoPosao crttDGiNO- OUMPIMO sire IILU netoi «^/ZalP** ^ " -T x A t MI N 9 ' NACIOMAI .rgg^' J^HV•—^ « SALAMANC0 U IS A

cuxwso REAC THfP O Hf Accès* CUAMKIC TO TUS TCIMIMA». pootieo ocaTH"-"» A^EAe o O T , Vf TO TMO t-ePT OP THIÎ. preavious onr, VITH THE Op TMC

oo Figure 5.13- Magdalena rive t Barranquillra a MAX

MIN

(öfter LEHLF, Barronquillo) Figure 5.14 - Flow-rate (1991-1992), water level and exceedance level frequency (1940-1991) in Magdalena river at Calamar station dredged region pointed before, including the variation in composition related to the river flow regime. Ground glass (0.160 mm < D < 0.250 mm) labelled with 192Ir, will be injected on the bottom, in the low water season, and followed from dry to rainy period. If the material is moved by the currents at a rate that avoids a further decreasing of the depths dangerous to navigatio nfuture purposesth o et e dumpin du e dredge, th f go d materiale b aree n th ,aca chosen for the new dumping site. This will have, as a consequence, a shortening of 20 km in the sailing distance of the dredger during a round trip, with an economy of about two hours in each dredging cycle (period 0-tj in Figure 4.8). Furthermore, measurements with a JTD3 backscattering density gauge are being performed in the well of the dredger, hi order to collect density profiles. This will allo drawo t curvee wth s indicatin variatione gth , with e timeth f o , weight of the dredged material contained in the well of the dredger as a function of the sand content which turns it y ,,b rive e relieth rn sfloo w regime pointes ,a beforet dou . The joint applicatio f thes no nucleao etw r technique e dredginth o t s g works being performed in the last reach of the Magdalena river could result in an optimisation hi the dredging cycle (FIG. 4.8) with an estimated average dredging cycle time reduction of about 42% [52], in case the new dredging disposal site could be used.

FINAL COMMENTS AND SUGGESTIONS Things hav changet eno d very much sinc comprehensive eth ef o repor e abou] us [2 te th t nuclear technique sedimenn si t transpor sedimentatiod tan n problems. Nuclear technique fiele sedimenf th do n si t transport have mor lesr eo s stratifie timen di , after an initial period of rapid development. In opposition, conventional techniques are always improving and some developments are making possible and advantageous their use in fields wher e tracerth e s wer e uncontesteth e d kings, some years ago n additio.I o thatt n , hydroinformatics presente remarkablda e developmen lase th t yearsn i t solutioe e Th .th f no hydrodynamic and transport-dispersion equations are now almost standard and recent advances in modelling of sediment transport have taken over the most important areas of developmen numericae th n o t l modelling side. A picture like that is not optimistic regarding the future use of nuclear techniques. It remember littlsa e situatioth e f developinno g countrie comparison si n wit developee hth d ones. Time works agains developine th t g countries t abl ,no incorporato et tha e ar t w ne e technological improvements at the same rate of their developed conterparts - and still less capabl f creatino e technologiew gne e desireth t a sd speed situatioe Th . n ask r drastifo s c modification in the attitude of the users of nuclear techniques. This lac optimisf ko m tracerf regardino e s limite sus i fiele e f sedimenth o dg th o dt t transport studies. Other applications of stable and radioactive tracers are in a phase of rapid progress examplr fo s ,a e reservoir sedimentatio hydrogeologyd nan . This last field seeme b o st wite on h e morth e potential s mora , e than ninet r cen f ydrinkablpe o t e wate s locatei r d underground - but, again, it must be treated using an adequate combination of nuclear and conventional techniques. future Th f nucleao e r gauges, mainly those usin activitw glo y sources, shows some promise. The concept of "navigable depth", that considers the depth in which a density of the mixture mud/wate t/m2 1. s stil^ a s i rl adequat navigationr efo , will generate considerable opportunitienucleaf o e us re gaugesth r definitiose fo .Th amoun e th dredge e f b f n o o o t d dan

87 the dredging programme can, and is generating, important economies to harbour operators. Equipments that use computer controlled winches, allowing to follow a pre-selected value of density ideae intensivr ar , fo l e survey largf so e regions presenting fluid mud t ver,bu y useful obtaineresulte b simplf n o s ca e d eus wit instrumentatioe hth n (twin-prong transmissiod nan single-prong scattering gauges), when small region surveyede sar . These instrument onle sar y to be applied in harbours where mud sedimentation is important. Besides the case cited in this report (Alumar harbour, Sâo Luis - item 5.2), they are also being used at Rotterdam, Zeebrugge somn i d e an ,harbour Indonesian si gaugee Th .alsn sca o be/used establiso t e hth optimum dredging time in overflow, by measuring the density profiles inside the well of a trailing suction hopper dredger. For these measurements, there are no conventional techniques available. Nuclear gauge alse sar ogooa d optio r "in-situnfo " river measuremen f suspendeo t d sediment concentrations higher tha g/L0 n1. . Yet usee ,b thefixes dn a yca d installationd san automatically record concentrations during flash floods. Their use is thus somewhat limited, usefue b t thearin n i bu ly ca d zones tropican i r o , l regions subjecte heavo dt y rainstorms, coupled to some device for the remote transmission of the collected data. Nevertheless, the acceptance of these systems throughout the world has been limited. In this case, one has a good example of the improvements introduced in conventional technique e cas clayd th f nucleasile eo r an t Th s.fo r techniqu s somewhaei t limitee th y db value of the relatively high threshold concentration, as pointed out before. Even with this limitation, nuclear e a equipmenoptiocontinuou on r fo s n wa t s determinatiof o n concentrations e conventionath s a , l techniques were mainly base n samplino d d an g gravimetric methods. If another detection system, based for instance in the attenuation of light, was used to cover the range outside the capability of the nuclear instrument, it was possibl havo et econtinuoua s recordin suspendee th f go d conventionae loarivera th t n di .Bu l equipment has shown recently an important evolution. New instruments based on light or infrared scattering or transmission have been developed and cover concentration values in the range of 0 to 10 g/L. They will probably substitute nuclear equipments almost immediately. However, nuclear gauges, due to its strength, are still indicated for measurements in very severe hydrodynamic condition presence th n i higf d eo san h debris load. problee Ifth determinatioe th ms i concentratioe th f no f suspendeno d sand, then again nuclear instruments prevail. Conventional device stile theisn ar i l r infanc reliancd yan e must be placed upon the traditional sampling by bottles or by pumping. The most promising system e radiateus s d ultrasound t theemployee bu ,yar d only with extensive site-specific calibration by sampling. The presence of micro-bubbles, as occurring in the breaker zone, affect response th s f suspendeeo d sediment gauge s e accoustibaseth n do c scattering. Since then- presence do not affect the response of nuclear gauges, they are an alternative for the measurin higf go h concentration sanf so d suspension sure th f n szonei . Definition of disposal sites for dredging spoils is a field in which tracers have been largely used and studies will probably remain, since their economic results are considerable, reducing bot e returth h f dredgeo n d materia o undesirablt l e location e distancth d an se travelled by the dredger. The same consideration is valid for the disposal or study of the movemen f participato t e waste. Concern with environment will probably contributo t e increase this application. Another application that may prove useful is the study of the long- term behaviour of dumped dredged spoils. In some cases, even if a tracer experiment has previously define e short-terth d m behaviou e sedimenth f o r t dumpe particulaa t da r site, information must stile needeb l d abou s long-terit t m destination, particularly whee th n dredged volumes are important. One possibility is to label the dredged sediment with

88 radionuclides like 181Hf (half-lif days5 4 r 160if o )o e b (half-lif days3 tak7 d f an )eo e samples for some months at its possible destinations. Since the dilutions will be enormous, the samples must be analysed using high-resolution solid-state detectors. e casI nth f agitatio o e n dredging instancer fo , e orientatioth , pipeline th f o n e that discharges the dredged material from a suction dredger can also be optimized, through the labellin dredgee th f go d materia t witlje htracera same Th .e metho usee b defin o dt n de ca eth deposition patterns followed by the mud, immediately after the opening of the bottom ports of a dredger or a barge. A radioactive density gauge mounted in a pole or moored and situated near the sea bottom, may also be used to monitor the deposition pattern of the highly dense mud cloud that reaches the bottom due to the downwards vertical momentum, just after dumping. dispersioe case Ith nth f eo suspendef no d sediment, conventional technique limitee sar d to the collection and analysis of samples, which is a heavy and not very precise method. Even whe nnaturaa l trace availables ri , which woul bettea e db r optio radioactivf o e n thaus e nth e material, the direct detection is still favourable to the nuclear method. In this field, radioactive tracers have their strongest point, both for pollution studies and for dredged material disposal. Since the same technique used for the dispersion of sediments is applicable to the study of the behaviour of chemical, organic and thermal pollutants, it is evident that a tracer group should also be active in this area Probably working opportunities will be more easily found in dispersion studies that interest both port operators and environmental authorities. bed-loar Fo d studies rivern i , oped san n nucleaseae th , r methods remai bese nth t option for field studies. Conventional method t presenno necessaro e sd th t y degre f confidenceeo . The use of sampling equipment deposited on the bottom to retain the moving sand grains does not always give coherent results. The procedure is heavy and uncomfortable, both to locate samplee th adequate th t ra e positio bottorecovee o t th d n mno an afte t r i samplin e rth g period. The determination of bed-load through the recording and evaluation of bottom configuration east interpreno yo t s si resultd tan s obtaine vert no y e precisedar . Even being more advantageous and precise, nuclear techniques need improvements in the determination of the mean transport depth, as is stressed in this paper on the description of the method. Practically all the experiments being performed are using glasses containing 198Au, 46g r 192co ^ smce surface labellin f naturago l sediment s usei s d onl verr yfo y special applications. The best option available now is the use of the count-rate balance method plus core sampling, but a better alternative would be to substitute core analysis by a more direct approach based on the properties of radiation. The suggestion of Dr. Plata Bedmar (item 3.3.1), relating the differences between the simultaneous recording of the Compton region and photoelectrie th c pea differenko t t transport depths seem vere b yo s t promising. In energetic flow environments, tracers tend to fail. High dispersion rates acting over the labelled sediment sometimes interfere with - or even eliminate - the possibility of the quantification of movement, mainly for fine grained sediments. This limitation cannot be ignored during the planning of experiments. A possibilit solvyo t e this problem causes i t i seasonaf y ,i d b l weather variations, would tracerf o e us s e durinth e b g period relativelf so fiowratw lo y r calo ea mrivese r conditiond san employ the results to calibrate mathematical models of sediment transport. The feasibility of this approach must be established. This problem can be transformed into an opportunity, since it creates the possibility of an investigation about the modality of bed material transport (bed-load or suspended load,

89 such as pointed out in figure 2.1) and the definition of the hydrodynamic conditions for which transpore th f o e t on modes prevail. Another potentia tracerf load o dbe e studien us ls i determinatio e th s si adequate th f no e sediment grain use e sizb artifician di o et l beach nourishmen dredginy b t g works resumen I . , onsayn naturae eca th : l sorting mechanis frontae sanf mth o y db l actiowavee a th f n nso o resuls beaca s th ha tha coarsee th t r sediments have their equilibrium positio beace th n nhi profile, neare shoreline th r e tha finee nth r ones. Then f sani , d coarser tha naturae nth e on l existing on the bottom, in front of a beach, is dumped at that place, it may be naturally moved shorewards, by wave action, and may fill the beach. Experiments with radioactive tracers using differen weld an tl sorted grain size distribution e applieb n o quantifca t ds y this crosshore sand movement at various depths and for different hydraulic and météorologie conditions, befor methodologe eth beacf yo h nourishmen decideds i t . Thi alss si opowerfua l too calibrato t l e mathematical model r crosshorfo s e sedimen tmore transportth f eo e on , difficult subjects of the coastal engineering science. There are no conventional alternatives to stud o precisels y y this mechanis e prototypeth s n madvisabli i t I . e tha a detailet d hydrodynami sedimentologicad can l aree studth a f y(wavo e climate, beach profiles, bottom sediment grain size distribution and its seasonal variation) be performed before or in parallel with tracer application. Some attempts have been made to use radioactive tracers in the breaker zone for determination of littoral drift. Success has been obtained for moderate wave climates, but the applicabilit o moryt e energetic condition s stili s l very difficult thin I . s casee mosth f o t transport occurs in the form of suspended sediment. A possibility is to use nuclear gauges to determine the concentration of suspended sediment, since the concentrations observed are in the measuring rang thesf eo e equipment determinatioe Th . suspendef no d sediment transport rates still depends on reliable and meaningful measurements of water velocities in the surf zone. Furthermore, tracer nuclead an s r gauge e improvemenalsn th e use ca sob r fo d f o t dredging operations and also employed for further development of the way of disposal of spoil dredginy sb g equipment, taking into account disposal sites submitte higdo t h currents. havarrivee w W poinea no o dt f difficul o t t definition problea t i opportunity n s a i : mr o ? In strategic planning, problems must be transformed into opportunities that will contribute for the development of the organization or the field of research. We are speaking of the explosive improvement of the mathematical modelling of processes thaalss ha ot arrivearee sedimenth f a o o dt t transpor depositiond an t alwaye Th . s increasing capacit computerf yo enablins si developmene gth modelf o t s thaincorporatn ca t e and proces almosn sa t unlimite f parameterso t dse . Moreover, throug variatioe hth thesf no e parameters modele th , able producsar o e t serieea resultf so s from whic mose th h t congruent outpu observeo t t d resultselectede b n sca . More the usede yar , mor confidence eth thein ei r results will increase goo.A d model witd adequate fe ,h th e conventional data, could thus turn tracers into obsolence? Tracers however have an important advantage: they are able to integrate the effect of all hydrodynamic agents that have acted upo sedimene nth perioa r timetfo f do . The thun e yca sb used as an important tool for calibrating models. It is evident that a model which is able to present results confirmed by direct measurements in the prototype will be regarded with an increased degree of confidence by the user. From these comments some aspects should be stressed:

90 •Tracer groups wil lonle tenth gn d i rangtransforme e b o et d into multi-disciplinary teamst I . sufficient no s i havo t t completea e domai nucleaf no r techniques alss i t o;i necessar havyo t e a strong knowledge on the fields into which tracers are being applied. Groups profficient onl nuclean yi r technique anachronismn a e sar . •Mathematical modellin anothes gi r aspect absolutely necessar traceo yt r groups. Since eth fiel presentins i d explosivn ga e development expectee b o t s i d t i ,tha t tracer groupo t y str follow the most recent progresses in the area where they apply nuclear techniques. This is evidentl yvera y difficult taskthes i t nI . importan woro t collaboration ki n with hydraulic institutions where action is occurring. Mathematical modelling is the future (and even the present ) and it is not wise to row against the tide if our intention is to survive. • Since a tracer group never works only in sediment transport, another important support can be obtained from environmental organizations, mainly government agencies thamore ar t e abl consideo et r alsbenefite t e onlnucleaoth th no yf d o sthei an r r problems r thesFo . e agencies specifie th , c propertie tracere th providf n so s ca e much needed information about concentratiothe eth fatd ean pollutantsf no . • It is a truism that tracers are only a tool to obtain specific informations. The interpretation of the results needs also a support of conventional measurements necessary to the full understanding, explanatio exploratiod nan experimentaf no l data. This means that tracerd san conventional measurement conflictn i contrar e t th no n e o ;s ar y ,the complimentarye yar e Th . important poinsolvo t probleme s i te th , preferably bese usinth tl optiongal s availablr efo this solution. Trace• r technique i erosiosh sedimentologd nan needine yar g another development phase. The utilit thesf yo e techniques remain f greaso t interes therd vere an t ear y many problems wher appliede b the n yca , mainl developinn yi g countries instancer .Fo possibilite on , y that has never bee nf artificia o full e yus ltestee cationith s di c tracers (l^Au, e 59pm r o ef ) labellin stude f th soi glocao f i y o h l l erosion. Some weak pointtracee th f sro techniquen si sedimentological studies have been already cited interestine t woulb I . y dma g that IAEA starte studw ne dy programme relate o thest d e techniques, coordinatin a gresearc h programme involving all the pertinent groups. • It is much easier to solve problems of a region, for instance Latin America, using experts that same worth en ki region . This avoids cultural shock and, sinc probleme eth regioa f so n are mor lesr eo s similar expere ,th t will kno advancwn i difficultiee eth expectede b o st . This policy is being used by IAEA and must proceed. Besides that, many regions in the world still have important problems that nuclear techniques could contribute to solve, hi some cases, the country authorities are not quite familiar with the extended possibilities of these techniques possibilitA . y that coul e evaluatedb e creatioth s di t IAEna f "itineranAo t experts" that, afte initian a r l agreement fro responsible mth e country authorities, would visit the country and define problems that would be studied with the help of nuclear techniques. Evidently the expert would also give a general orientation about the necessary steps to arrive at their solutions. This approach, whose feasibility mus previousle b t y established, would contribute to the implantation of new groups in regions where they can be very useful. • A common problem hi developing countries is the scarcity of funds for investment in new equipments. Our group still uses equipment that have been bought more than a decade ago. In opposition, developed countries have important reserves of equipment still operative that have been substitute mory db e modem ones suggestes i t .I d that IAEA could establis hkina d of "bank" that would distribute these equipments to the groups who need them. This would improv technicae eth l capacit lesf yo s developed countrie almost sa expenso tn IAEAeo t .

91 • "In many studies, hydrodynamic conditions are only of secondary interest. The engineer is asked to determine, for example, how the prevailing waves and currents affect the spreading of a sewage discharge, and so determine the impact on the ecosystem. A good knowledge and accurate modelling is essential, but in practice this is just a "carrier" or "platform" for stude th othef yo r subject mosf s o tha e t tar immediat e interest." [54].

This paragraph shows the tendency adopted by hydraulic and environmental institutes, with an ever increasing confidence in the use of models. It is our task to convince them that a still increased degre f modelobtainee o b f confidenc e o modellinn e us th s ca e f di th n i eg result e verifiesar d through some tracer experiments opinior ou s i nt I . that IAEA should evaluate this aspec defind an tstratege eth adoptee b o yt solvo d t problee eth improvinf mo g the collaboration between the nuclear and hydraulic fields, with emphasis in the sedimentological aspect thif so s interaction. importanIs ti nucleapoinf o t o tha t healte e tou tth us re h th hazard publio e t th e r cdu sfo techniques in sedimentological and hydrological studies are negligible. Specialists that apply these techniques have the knowledge and the instruments to limit at very low values the doses that they will receive. Thu restrictione sth s impose mann di y countrie somn i r eso institutions to this techniqu t deriveno e edar fro objectivn ma e evaluatio riskse th t simpl f no bu , y from prejudic dogmatir eo c positions against this kin applicationf do . One of the methods to change this overall situation would be to invite selected participants of hydraulic institutions, representatives from international associations for hydraulic or hydrological sciences, people engaged in the development of dredging technology and dredging port operators to the Agency's group meetings or to a defined symposium. The investment will probably be fruitful for both sides. Throughout this paper, it has been repeatedly stressed that the interaction with hydraulic institutes and laboratories is a necessity and we have partially failed in getting this interaction in the past. It is expected that a better understanding will arrive now.

REFERENCES [1] RAUDKTVI, A.J., Loose Boundary Hydraulics, Pergamon Press Ltd., London (1967). [2] CRICKMORE, M.J., TAZIOLI, O.S., APPLEBY, P.O., OLDFIELD, ,F. The Use of Nuclear Techniques in Sediment Transport and Sedimentation Problems, Technical Documents in Hydrology, International Hydrological Programm eIHP-ÏÏ, I Project 5.2, UNESCO, Paris (1990). [3] VAN LEUSSEN, W., Aggregation of particles, settling velocities of mud floes, Invit. Lect. (Int. Symp. Phys. Processe Estuariesn si , Leiden, The Netherlands 1986) Rijkswaterstaat & Delft Hydraulics Lab. (1986). [4] CRICKMORE, M.J., LEAN, G.H., The measurement of sand transport by means of radioactive tracers, Proc. R. Soc. (London) Ser. A 266 (1962). [5] HUBBEL, D.W., SAYRE, W.W., Sand transport studies with radioactive tracers, Amer. Soc. Civ. Engs. Hydr. Div (1964)0 9 . . ] COURTOIS[6 , SAUZAYG. , méthodes Le , ,G. bilae tauss d ne de x d comptag traceure ed s radioactifs appliquée mesura l s à débit s ede s massique charriagee sd , Houille Blanch (1966)e3 .

92 [7AUZAYS ] , Méthod,G. Bilau e Taud s n Comptagede e xd s d'Indicateurs Radioactifs pour la Détermination du Débit de Charriage des Lits Sableux, Thèse d'Ingénieur Docteur, Faculté des Sciences de Toulouse, CEA R. 3431 (1967). [8] BOUGAULT, H., Étude de la Sorption de Quelques Radioéléments Artificiel Sédiments le r spa Application sso Pélitiquee d e u nVu a n se Marquage Radioactif des Matériaux, Thèse d'Ingénieur Docteur, Faculté de Paris, CEA R. 4094 (1970). radioactivf o [9e ] us TOLAe eTh , tracer,F. dynamin si c sedimentology (Regional Seminar on the Use of Isotope Techniques in Water Resources Development, Athens, Greece 1981) IAEA.(1981). [10] AUN, P.E., MENDES, V.L., Radioactive tracers in the study of the movemen sedimentf to s (Regional Trainin Isotopf o e g Us Cours ee th n eo Technique Environmentan si l Studie Hydrosphere th f so e th d ean Atmosphere, Piracicaba and Belo Horizonte, Brazil 1992). IAEA (1992). [11] CAILLOT t al.e . , Étud,A Laboratoiru ea Sitn I Comportemen u t ued e t Hydrodinamique des Fines Particules en Suspension, à l'Aide de Traceurs Radioactifs (Technical Co-operation Project BRA/8/018, Belo Horizonte, Brazil 1978). IAEA (1978). [12]HAECON Harbou- Engineerind ran g Consultants, Étude Moyeu ,a e nd Traceurs Radioactifs, du Réciclage des Produits de Dragage du Port de Zeebrugg Chenaus de t ee x d'Accè Portx sau s Belges (Zeebrugge, Anvers, Ostende,etc...), Dossier Technique, MBS460,87.2248 (1987). [13JPRUSZAK , ZEIDLER,Z. , R.B. changed ,Be sedimend san t movement sure inth f zone (Proc. 23rd Int. Conf Coastan o . l Engineering, Venice, Italy 1992). American Societ Civif yo l Engineers (1992). [14JKRAUSS, N.C., ISOBE, M., IGARASHI, H., SASAKI, T.O., HORIKAWA , Fiel,K. d experiment longshorn so e sediment transport rates (Proc. 18th Int. Conf. on Coastal Engineering, Cape Town, South Africa 1982). American Society of Civil Engineers (1982). [l5]DRAPEAU , LONGG. , KAMPHUIS, ,B. , J.W., Evaluatiof no radioactive sand tracer measuro st e longshore sediment transport rates (Proc.22nd Int.Conf Coastan .o l Engineering, Delfte Th , Netherlandsl 990). American Society of Civil Engineers (1990). GRAAFFR DE N [16, "Onshore-offshor,J. VA ] e sediment transport" Coastal Engineering, Volum , IntroductioneI , Coastal Engineering Group, Dept Civif .o l Engineering, Delft Universit Technologyf yo , Delft Netherlande Th , s (1982). [17] COURTOIS, G., ANGUENOT, F., MAGLOIRE, C., Turbidimétrie: absorptiométri radioactivitu o y - eX é naturelle? (Proc. Sympn .o Isotope Hydrology. IAEA, Vienna 1970). MARTIN] 8 l [ , J.M. jauges ,Le s radioactive turbidimétriee sd , Houille Blanch (1970e8 ) 745-755.

93 [19JPAPADOPOULOS, J., ZIEGLER, C.A., Radioisotope technique for monitoring sediment concentration in river and streams (Proc. Symp. Radioisotope Instruments in Industry and Geophysics, Warsaw 1965). IAEA, Vienna (1966) 381-394. [20]BANDEIRA, J.V., AUN, P.E., In-situ measurement of suspended sediment concentration - development of a nuclear gauge based on the transmissio f gammno a radiation (Proc Braziliah .8t n Symp Waten .o r Resources - Brazilian Water Resources Association-ABRH, Foz do Iguacu, Parana, Brazil 1989) Portuguese)n .(I . [21JFLORKOWSKI CAMERON, ,T. , J.F. simpl,A e radioisotope X-ray transmission gauge for measuring suspended sediment concentrations in rivers (Proc. Symp Radioisotope Instrument Industrn si Geophysicsd yan , Warsaw 1965). IAEA, Vienna (1966) 395-410. [22] FLORKOWSKI , Portabl,T. e radioisotope gauge suspender sfo d sediments (Proc. Symp. on Use of Isotopes in Hydrology, Vienna 1970). IAEA (1970) 545-554. [23] RAKOCZI , CriticaL. , l revie currenwf o t nuclear suspended sediment gauges - techniques in sediment transport, IAEA, Tech. Rep. Ser. 145, Vienna (1973). [24] TAZIOLI, O.S., "Nuclear technique measurinr sfo g sediment transporn ti natural streams - examples from instrumented basins" (Proc. Florence Symp. on Erosion and Sediment Transport Measurement - International Association of Hydrological Sciences-IAHS, Florence, Italy 1981). (IAHS Pub. 133)63-81. [25] CIET, P., TAZIOLI, G.S., Radioisotope methods for measurement of suspended sediment transport, Geol. Appl Idrogeole . (1976)I . p , .XI (In Italian). [26] TAZIOLI, G.S., "Nuclear gauges for measuring sediment transport in torrential water courses", Radioisotope Sedimenn si t Studies. Repora f to Consultants' Group Meeting on Radioisotopes in Sediment Studies, Vienna (1983). IAEA TECDOC-298. [27] TAZIOLI, G.S., CAILLOT . "Measuremen,A suspendef to d sedimenty sb nuclear techniques", Guideboo Nuclean ko r Technique Hydrologyn si , IAEA Tech. Rep. Ser Vienn, .91 a (1983). [28ZfflYURENU U ]L LI , LELINGN SU , XIANGLINU ,X YUJINGN ,VA , KONG LINGOI, "The development of nuclear sediment concentration gauges for use on Yellow River" (Proc. Florence Symp. on Erosion and Sediment Transport Measurement - International Association of Hydrological Sciences-IAHS, Florence, Italy 1981). (IAHS Pub. 133). [29]BANDEIRA, J.V., Sedimentation Processes in Coastal and River Environmen Selecte- t d Topic Hydrologn si Rived yan r Sedimentology (Regional Training Course on the Use of Isotope Techniques in Environmental Studies of the Hydrosphere and the Atmosphere, Piracicaba and Belo Horizonte, Brazil 1992). IAEA (1992) Spanish)n (I . .

94 [30]ROSSO, R., TAZIOLI, O.S., Suspended sediment transport during flood flows from a small catchment" (Proc. 18th Cong. International Association for Hydraulic Research-IAHR, Cagliari, Italy 1979). [31]FREGA, G.A., LANZAFAME MARONE, G. , , TAZIOLI,V. , G.S., ZUFFA, G.G., Problems of measurement of solid transport in a small basi Ilice. n(T , Calabria), Geol. Appl Idrogeol.e (1976)I . p , n .(I .XI Italian). [32] TAZIOLI, O.S., BILLI , TACCONI,P. fluvian "O , l ,P. dynamic Italy"n si , The Lithosphèr Italyn ei , Advance Eartn si h Science Research, Accademia Nationale dei Lincei, Rome, May (1987). [33] SALIM, L.H., MINARDI, P.S.P., BANDEIRA, J.V., AUN, P.E., Report of the First Survey of the Bottom at the Turning Basin and Access Channel to Alumar Harbour - Sâo Luis, Maranhäo State, NUCLEBRAS/CDTN Rep. DERL.PD-016/83, Belo Horizonte, Brazil (1983). (In Portuguese). [34]MEYER, G., CHAMBELLAN, D., CAILLOT, A., MGNIOT, C., Use of nuclear density gauges for studying and measuring silt deposit formatio concentratiod nan laboratore th sitn n i i ud (Procyan . Symp. on Use of Isotopes in Hydrology, Vienna 1983). IAEA (1984) 741-752. (In French). [35] CAILLOT MEYER, ,A. , CHAMBELLAN,G. , TANGUY,D. , J.C.,A nucleaw ne r gaug measuro et e high turbiditie muddn si y areas (Proc. 19th Int. Conf. on Coastal Engineering, Houston, USA 1984). American Society of Civil Engineers (1984). [36VLIEGERE ]D CLOEDTE D , ,H. Navitracker, ,J gian:a t step forwarn di tactic economicd san maintenancf so e dredging, Terr Aqut ae (1987)5 a3 . [37] AUN, P.E., BANDEIRA, J.V., BOMTEMPO, V.L., MOREIRA, R.M., SALIM, L.H., CASTRO, J.O.N.M., MINARDI, P.S.P., PINTO, A.M.F., NETO, A.F., PINTO, G.G., GOMES, R.S.; AUN, L.R., MENDES, V.L., SOUZA, A.D., COSTA, D.A., Selection of spoil disposal areas in Brazilian harbours with the aid of tracer techniques (Proc. 3rd Int. Conf. on Coastal & Port Engineering in Developing Countries - COPEDEC III, Mombasa, Kenya 1991) 950-962. [38] AUN, P.E., BANDEIRA, J.V., Final Report Abou Viabilite tw th Ne f yo Areas for Dumping of the Dredging Material at Santos Region - Vol. I & II, CBTN/IPR, Belo Horizonte, Brazil, August (1974). (In Portuguese). [39] BOMTEMPO, V.L., PINTO, A.M.F., MOREIRA, R.M., AUN, P.E., Hydraulic and Sedimentological Studies for the Determination of New Areas for the Dumping of Material Dredged in Santos Bay and Harbour - June & July, 1985, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Rep. DERL.PD-001/86 (1986). (In Portuguese). [40] BANDEIRA, J.V., BOMTEMPO, V.L., AUN, P.E., MINARDI, P.S.P., PINTO, A.M.F., BehaviouStude th f yo Bottof ro m Sediment Santon si s Bay Between June/80 and June/81, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Rep. DERL.PD-042/81, (1981) Portuguese)n (I . .

95 [41] SONDOTECNICA, Hydrauli Sedimentologicad can l Behaviou Santof ro s Estuary Janeiroe d o ,Ri , Brazil. Technical ReporMinistre th r tfo f yo Transportatio nEmpres- Portoe ad Brasilo sd - PORTOBRA SInstitut- e od Pesquisas Hidroviarias -INPH (1977) Portuguese)n .(I . [42JMOREIRA, R.M., BANDEIRA, J.V., Study of the Dumping of Spoils from Maintenance Dredging of Alumar Harbour into Säo Marcos Bay, Maranhäo State, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Rep. DERL.PD-009/84, (1984). (In Portuguese). [43JMOREIRA, R.M., BANDEIRA, J.V., Study of the Dumping of Spoils from Maintenance Dredging of Alumar Harbour into Estreito dos Coqueiros, Maranhäo State, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Rep. DERL.PD-019/84 (1984). (In Portuguese). [44] SALIM, L.H., Hydrauli Sedimentologicad can l Measurement Estreitt sa o dos Coqueiros and Rio dos Cachorros, in the Surroundings of the Alumar Harbour, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Rep. DERL.PD- 022/84 (1984). (In Portuguese). [45JBOMTEMPO, V.L., BANDEIRA, J.V., AUN, P.E., Bottom Sediment Transport Studie Accese th n si s Channe Alumao lt r Harbou Luio Sä s- r- Maranhäo, Using Radioactive Tracer, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Rep. DERL.PD-020/84, (1984). (In Portuguese). [46] WILSON JR. RODRIGUES, G. , , SANTOSH.T.S ,DO , J.S., Hydraulic and Sedimentological Studies Performe Lowee th n di r Reac Ivaf ho i River, NUCLEBRAS/CDTN, Belo Horizonte, Brazil. Final Report CDTN/NUCLEBRA SARH/Paran- a State (1979) Portuguese)n (I . . [47] BANDEIRA, J.V., Sedimentological Studies in La Juventud Reservoir, San Juli a DiegL ad Riversoan Cuban i , , Using Nuclear Techniques, End- of-Mission Report, IAEA Technical Co-operation Project CUB/8/009, December (1990). [48] BANDEIRA, J.V., Sedimentological Studie Juventua L n si d Reservoirn i , Cuba, Using Nuclear Techniques, End-of-Mission Report, IAEA Technical Co-operation Project CUB/8/009, December (1991). [49] ALVARADO O., M., Magdalena river estuary, general results of hydro- sedimentometric measurements, Rio Costasy Bogot, s1 aColombia- y ,Ma (1990) - (in Spanish). [50] BANDEIRA, J.V., Isotope-Aided Sedimentology Studies, First Field Report, IAEA Technical Co-operation Project C3-COL /8/012, December (1988). [51] BANDEIRA, J.V., Applicatio Radioactivf no e Tracer Techniquee th r sfo Stud Bottof yo m Sediment Transpor Colombian ti , End-of-Mission Report, IAEA Technical Co-operation Project COL/8/018, June (1991). [52] BANDEIRA, J.V., PINTO, G.G., Applicatio Radioactivf no e Tracer Technique Stude th Bottof r yo s fo m Sediment Transpor Magdalenn ti a River - Barranquilla, End-of-Mission Report, IAEA Technical Co- operation Projec /8/018L CO t , February (1993).

96 [53] IAEA, INEA, LEHLF, Aplicaciön de Técnicas Nucleares en Sedimentologia. Optimizatio Botaderl nde Draga l e od a Bocae sd Ceniza, Rio Magdalena-Canal de Acceso al Puerto de Barranquilla, Compilation of Hydraulic and Sedicnentologic Information Performed by the Laboratorio de Ensayos Hidraulicos de Las Flores (LEHF), Barranquilla, 8-18 February (1993). [54] INTERNATIONAL INSTITUT INFRASTRUCTURALR EFO , HYDRAULIC AND ENVIRONMENTAL ENGINEERING (IHE)., International Cours Hydraulin ei c Engineering, Branc: hd Hydroinformatics, Delft Netherlande Th , s (1993/1994). Folder.

97 LINKING LAND USE AND RESERVOIR SEDIMENTATIO APPROACHEO TW Y NB S UTILIZING 137Cs

S.C. MCINTYRE USDA ARS National Agricultural Water Quality Laboratory, Durant, Oklahoma, United State Americf so a

Abstract

o approacheTw s were use quantifo dt e effectth y pasf o sreservoin to lane dus r sedimentation. In both approaches, land use was determined from time sequences of aerial photographs and the Universal Soil Loss Equation was used to estimate potential sediment production. Determination of reservoir sedimentation where retention ponds were built combined Cs techniques with direct measurement sedimentatiof so retention i n ponds. 137 Where retention ponds had not been built, determination of reservoir sedimentation was with l Cs techniques. Sedimentation in Tecumseh Lake, where retention ponds had not been constructed, decreased from 5,933 Mg/y 193n ri 1,017o t 7 Mg/ys wa 1984 n rt i i d ,an significantly relate decreasa o dt watershen ei d are cultivation ai percent3 no t fro 9 m5 . Sediment retention ponds that were built in the early 1980s above Pauls Valley Lake reduced reservoir sedimentation by 6,400 Mg/yr. Sedimentation in Pauls Valley Lake decreased from 37,500 Mg/yr hi 1956 to 19,950 Mg/yr in 1992. The decrease in sedimentatio significantls nwa y relate installatioo dt retentio2 1 e th f nno ponda d an s decrease in watershed area in cultivated or abandoned gullied fields from 34 to 3 percent. approacheo tw e Th s make possibl quantitative eth e determinatio effece th pasf f o tno t land use on reservoir sedimentation.

1. INTRODUCTION

Relating reservoir sedimentation quantitatively to long-term agricultural land use has generalh' not been done since most investigators have either studied erosion or reservoir sediment deposition t botno ht investigator[1]e bu , .Th s that have considered both aspects have for the most part determined times of major land use changes but not quantified them. Their primary interests chronolog e werth i eh sedimenf yo t depositio , 3,4n[2 . ,5] ] use[6 quantitativda e Le Stald an l e approach when studying sedimentatio Lakn ni e Springfiel agriculturad dan watershes it n l o lane western dus i n Illinois. They founda relationship between land use and reservoir sedimentation but relied on land use estimates. Kelly [1] quantitatively investigated erosion and sedimentation in a small forested lake- catchment in central England. The primary source of sediment in the forested catchment, however, was from natural stream bank erosion rather than land use. In the present study, two approaches were used to quantitatively link past agricultural land use and reservoir sedimentation e approacOn s .use wa hd where sediment retention pond d beeha s n constructed abov reservoirea othe e uses th rwa d wheran , e retentio nt bee pondno nd sha built.

99 2. APPROACH WITHOUT RETENTION PONDS

. 2.1 Study area

The approach without retention ponds was used to investigate sedimentation in Tecumseh Lak long-terd ean watersheds it m f o lan e dus . Tecumseh Lak55-ha s ei a reservoir averaging 2.3 m in depth. It was constructed in 1934 and is located 45 km southeas f Oklahomo t a City ,watershe Oklahomakm 2 1 s locatedi s It . rollinn do g 2 uplands and has soils predominantly of the Weatherford (fineloamy, siliceous, thermic Ultic Haplustalfs) - Chickasha (fine-loamy, mixed, thermic Udic Argiustolls) association . Erosio loa[7] e th m f n o soil problea s si m when plowed becaus percen5 e o slopet 3 tf so cove percen9 watershe5 re th averag e f th o t d dean ?nmiae th 1 n precipitatioI . cm 0 9 s ni past, cotton maifarmine watershede th th n s f amoune o lan gwa th e t d us cultivatef bu ,o t d land has declined due to changes in crop production economics.

Method. 2.2 s

Sediment depth in the reservoir was measured with a probe at 33 sites spaced about 9apar0m t alon transactg8 s which average apartm 0 d.20 Sediment depth coule db identified becaus difference th f eo densitn ei y preimpoundmenbetwee4 193 e nth t soil reservoie surfacth d ean r deposited sediments. Sediment fivt sa e sites were sampled witha 5.5-cm diamete rsedimene corerth d ,an t cores section werm intc t e0 cu o 1 s beginnint ga the sediment surface (Figure 1). The sediment profile was investigated in greater detail by collecting four 13-cm diameter sedimen largee Th t. r 5 core sedimend t sitea san s2 t cores were divided into sections, and sections of like depth were composited at each site. The 3 cm of noticeably wetter sedimen sedimene th t a t t surfac collectes efirswa e th t s dsectiona . Belo firse wth t section, the sediment cores were divided into 2-cm intervals down to 20 cm. Below 20 cmcoree ,th s were divided intervals intm o5-c . In the laboratory, sediment samples were oven dried (50° C) and ground to pass through a 6-mm screen. The samples were analyzed for 137Cs with a multichannel analyzer usin glithium-driftea d germanium detector [8]. Cs activit r eacyfo h sample 137 was counted count e twicth 4,00r d esfo an wer 0s e averaged. After 137Cs analysis, samples were selected for particle-size distribution analysis, and 40-g subsamples were dispersed with sodium hexametaphosphate. Particle-size determinations were done by the hydrometer method [9].

s determinewa Lan e dus d wit timha e sequenc f rectifieeo d aerial photographs taken hi 1937, 1954, 1961, 1968, 1974, 1981, and 1984. The aerial photographs were obtained fro USDe mth A Agricultural Stabilizatio Conservatiod nan n Service land an ,d use areas were measured with a compensating polar planimeter. The scale of the aerial photograph abous swa whe4 t 1:8,00 scale l years 198 nth al ed wa r s 0an fo excep 4 197 t about 1:10,000 and 1:12,000, respectively. The actual scale of each photograph was measure lan r aree dfo dus a calculations.

Potential sediment productio yeadetermines y nb rwa cultivater dfo d field gross sa s soil loss using Universal Soil Loss Equation (USLE) published values for Oklahoma [10]. The average cultivate percen4 da field t d ha slopa slop . Annuad m e ean 0 lengt12 l f ho

100 OKLAHOMA

Sediment sample site — Contou30 f o r sediment depth (cm)

0 150m

FIG. 1. Locations of reservoir sediment sample sites and contours of sediment deposition in centimeters in Tecumseh Lake from 1934 to 1987.

county crop records were use estimatdo t yearle eth y percentag cultivatef eo d land planted to cotton, corn, sorghum or wheat [11]. Terracing was taken into account when soil loss estimates were made. Abandoned fields with gullied bare-soil areas were estimateo dt have a soil loss of 112 Mg/(ha yr) (D. Guy, SCS Pottawatomie County, Oklahoma, personal communication).

Long-term precipitation records of the reservoir area were examined to determine f long-teri m change precipitation si n occurred that could have caused major differencen i s rate f sedimentationo s recorde Th . s used were froe nearesmth t reporting statiot a n Shawnee, Oklahoma, which is 2.5 km northeast of the reservoir.

101 23. Results and Discussion

2.3.1. Sedimentation

Sediment deposite Tecumsen di h Lake ranget a thicknesm n dc i 0 7 o t s m froc 0 m3 probe sites. The top 3 cm of wetter surface sediment were found to represent 2 cm when normalized to average dry bulk density of the remaining sediment profile. The 2-cm normalized valu s useewa d throughou p sedimento e e studth th r tt fo ylayer . Depth contours were plottee reservoith f do r sediment deposits d sedimenan , t volums wa e determined totaA .211,90f o l sedimenf o 0m deposites wa treservoi e th n di r from 1934 1987o t . 3

The sediment had an average dry bulk density of 800 kg / m3and a weight of 169,52 . Particle-siz0Mg e distributio e sedimentth f no s average percend3 t sand6 3 , percen percen1 6 t siltd an t, clay. Since variatio particln ni e size distribution between sediment layers was not great, it did not affect interpretation of Cs results. 137 137Cs analysis mad t possiblei divido et e reservoir sediment deposition into three periods. Dividing the profile was possible because Cs produced identifiable markers in 137 sediments when it first became detectable in 1954, when amounts increased rapidly in 1962 and when the highest level in deposition occurred in 1964 [12, 13]. Sediment deposition since 195e s similafounb 4wa o t d r throughou e reservoirth t notablA . e increase in I37Cs activity signifying 1962 deposition occurred on an average at a depth of 6 e deepesTh . te sedimen poincm th n i t t where 137Cs activit s detectablewa y , which indicated 1954 deposition, averaged 12 cm. The depth of sediment deposited from 1934 averaged 39 cm and was indicated by the preimpoundment ground surface. The ground surfac distinguishabls ewa e fro sedimene mth haviny tb averagn ga buly edr k densit, 1 f yo averagn a d an e particle-sizm / g k 0 20 e distributio percen7 1 f no t sand percen3 5 , t sild tan 3 30 percent clay.

Cs dating indicated that 118,664 Mg of the sediment were deposited in the first 1:>7 20-year period from 1934 to 1954 which converted to an average annual rate of 1.35 cm/yr. Sediment deposition during the second period of eight years from 1954 to 1962 was 25,428 Mg which converted to an average annual sedimentation rate of 0.75 cm/yr. A total of 25,428 Mg of sediment was also deposited during the third period of 25 years from 1962 to 1987 but the average annual rate of 0.24 cm/yr was much lower, than the other periods.

2.5.2. Precipitation and sedimentation

Precipitation records for the Tecumseh Lake area indicated considerable variation among years (Figure 2). The precipitation for the period from 1934 to 1954 was marked by both low and high extremes with an overall average of 5 cm/yr above the long-term average of 90 cm/yr [141. The record shows that drought periods occurred in the 1930s anfirse d th 1950te halth f fso which could have reduced sediment production secone Th . d period from 1954 to 1962 was similar to the first in extremes, but had 2.1 cm/yr precipitation above the long-term average. This period showed increasing accumulated precipitation time e t woulmosi th o f s , o td have bee periona d with greater than average potential for sediment production. The third period from 1962 to 1987 did not have as great of extremes as the other two periods and ended with a 6-year period which was

102 continuously wetter than average lase tTh .perio d average cm/y8 d2. r abov long-tere eth m average. No long-term trend in precipitation was found which corresponded to the changes which occurred in reservoir sedimentation.

2.3.3. Land use

Land use was divided into six categories: abandoned fields with guilied bare-soil areas visibl i aeriaeh l photographs, cultivated fields, perennial pastures, forests, suburban areas miscellaneoud an , s areas. Perennial pastures included native grass land, abandoned fields without gullies thareverted ha t graso dt s land improved an , d pastures. Suburban areas were lands thabeed tha n subdivided houseintd oha lotd s san buil t upo . nLanit e dus placed in the miscellaneous category was primarily reservoir buffer land, farmhouse sites and county roadways. The major land use changes which occurred were cultivated and abandoned fields being replace perenniay db l pastures greatese Th . t change occurred from 193195o t 74 when abandoned field arereduces awa d fro percen2 mwatershee 2 th f to percen7 do t d an t cultivated field area from 37 percent to 17 percent.

Little change occurred in areas devoted to other land uses and in land use after 1961. Miscellaneous use accounted for about 2 percent of the watershed from 1937 to 1984 while forested land decrease percen7 2 d o t fro t2 m3 afte re mos 1961Th t .noticeabl e change in land use after 1961 was the start of suburban development in the mid 1970s. It occupied 3 percent of the watershed by 1982 but expanded no further. After 1961, agricultural land use was about 0.5 percent cultivated fields, 1.5 percent abandoned fields, and 66 percent perennial pasture.

160

140- U 120-

100-

Û. ü cLJeJ CL

1930 1940 1950 1960 1970 1980 1990 YEAR

FIG. 2 . Annual precipitation for the Tecumseh Lake watershed. Average annual precipitation is 90 cm.

103 Only two land use categories, abandoned and cultivated fields, were considered significant sediment sources because of the exposed soil and locations of many fields near ephemeral streams. Wilki Hebed nan l [15] have emphasized that land near streams i s more important as sediment sources. Perennial pastures and forest lands were not considered significant sediment sources since, through time, overgrazing has not been a problem littld an ,e timbe bees ha rn cut. Suburban lanconsideres dwa insignificann da t sediment source becaus thf eo e small amoun locatios it d tan n away from stream channels. miscellaneoue Lth i s category, reservoir buffer lans eithedwa r grasse r forestedo t i o ds significana wat sno t sediment source. Farmhouse sites were small, vegetatedt no d an , numerous so were also not a significant sediment source. Roadways represent a possible sediment source but since they were constant through time they were not considered to have contributed to changes in reservoir sedimentation.

Potential sediment production was determined for cultivated and abandoned fields in year measures s wa lan e dus d amounte (TablTh . potentiaf es1) o l sediment production and area fieldn i s s were linke averago dt e annual reservoir sedimentation using linear regression e relationshiTh . p between reservoir sedimentatio d fielan nd s arewa a significant at the 0.05 level and explained 92 percent of the variability in reservoir sedimentation. The relationship between reservoir sedimentation and calculated potential sediment production from fields was significant at the 0.05 level and explained 94 percent variabilite oth f reservoin yi r sedimentation resulte Th . s indicatee b tha n tca lane dus quantitatively linke sedimentatiodo t Tecumsen i h Lake.

TABL Are. E1 a useTecumsee fieldr th dfo n so h Lake watershed, potential sediment from fields reservoid an , r sediment deposition.

Year FieldArea Potential Sediment Reservoir Cult. Aband. Cult. Aband. Sediment Guilied Gullied Deposit.»

Uo Mg ———— Mg/yr

1937 439 266 5,048 29,792 5,933

1954 205 80 4,522 8,960 3,179

1961 43 80 1,010 8,960 3,179

1968 17 40 557 4,480 1,017

1974 2 15 32 1,680 1,017

1981 1 15 13 1,680 1,017

1984 14 15 222 1,680 1,017

* Average annual deposition for the period a year is in.

104 3. APPROACH WITH RETENTION PONDS

3.1. Study area

Finding that lan coule d us linke e db reservoio dt r sedimentatio Tecumset na h Lake, d reservoian lane us dr sedimentation were investigate t Paula d s Valley Lake where conditions included constructio f retentiono n ponds abov reservoire eth . Pauls Valley Lake is a 300-ha reservoir averaging 3.5 m in depth. It was constructed in 1954 and is located 80 km south of Oklahoma City. Its55-km watershed is located on rolling uplands and has soils predominantly of the Renfrew (fine, mixed, thermic Udertic Paleustolls) - Zaneis (fine-loamy, mixed, thermic Udic Argiustolls) association [16]. Watershed hill slopes range from 1 to 5 percent and are largely grass covered. Past land cultivation for corn and cotton has resulted in a number of gullied areas throughout the watershed. The gullies developed whe loae nth m soils were exposed soibecausw llo o f runoft eo e du f infiltration rates and -high average annual precipitation (84.3 cm/yr).

To reduce sediment from some of the seriously eroding areas, 12 sediment retention ponds rangin surfacn i a h sizn gi e5 eareo t fro a5 mwer0. e constructe U.Se th .y dSoib l Conservation Service between 198 1984d averag0e an Th . e completio nponde datth f eso was 1982 which was used in determining the effect ponds had on sedimentation hi Pauls Valley Lake. 3.2. Methods

Reservoir sédiments were investigate t fouda r sites wit h7.6-ca m diameter corer (Figure 3). Three cores were taken at each site and divided into 10-cm sections beginning e sedimenath t t surface. Like depth sections were composite t eaca d e hth siten I . laboratory, samples were analyzed as previously described for 137Cs and particle-size distribution.

Sediment retaine retentioe th n di n pond measures swa Junen di , 1992 wit h3-ca m diameter metal probe easile Th .y probe layep d to bottof ro m materia consideres wa l e dth retained sediment. Below this probe ,th e resistant ground surfac encountereds ewa , which existed when the ponds were built.

Paule th n sLan o Valle e dus y Lake watershe investigates dwa d with rectified aerial photographs taken in 1956, 1963,1969 and 1979. The scale of the photographs was about 1:8,000 in 1956, 1963, 1969 and 1:21,000 in 1979. Land use on the watershed in 1992 was investigate relatiny db g field observation aeriae th o slt photograph previoue th f so s years.

Potential sediment production by year was determined for cultivated fields as at Tecumseh Lake using the USLE. The average cultivated slope was 2 percent with a slope length of 100 m. Gullies in abandoned fields were measured on aerial photographs for lengt widtd sedimenhd an han t productio determines nwa d [17].

Long-term precipitation record reservoie th f so r area were examine determino dt f ei long-term change in precipitation occurred that could have caused major differences in rates of sedimentation. The records used were from the nearest reporting station 8 km southwest of the reservoir at Pauls Valley.

105 1 km

A Pond • Sediment sample sites <-Z2> Areas drainin o pondt g s

FIG. 3. Pauls Valley Lake, a 300-ha reservoir and its 55-km 2 watershe d showing2 1 locatio e th f no sediment retention ponds, watershed area drainin pondso gt d locationan ; f reservoio s r sediment sample sites.

106 33. Results and Discussion

3.3.7. Sedimentation

I37Cs datin possibls gwa foue thret ea th r f esamplo e sites. Analysis indicated that sediment shifted Sitt swera ha d t suitable4 d an eno 137r eCfo s dating. 137Cs activity levels signifying 1964 deposition occurred on an average at a depth of 45 cm into the sediment. e deepesTh t averag whicem c dept s detecte0 h7 wa h signifies s thaC d wa t d 1954 3 1 deposition e 195Th .4 dept confirmes hwa coincidins it y db g wit preimpoundmene hth t ground surface groune Th . d surfac distinguishes ewa d fro sedimene mth haviny b t n ga averag buly averagen dr k a densitd an e 3 f particle-siz1,10yo m / 0g k e distributio4 2 f no percent sand percen0 4 , percen6 3 t d silan t claysedimene averagn Th a . d buly ha te dr k density of 500 kg/m and an average particle-size distribution of 1 percent sand, 1 0 3 percen percen9 8 t siltd ,an t clay. The retention ponds intercepted runoff from one-thir e watersheth f o d d an d contained 128,000 m of sediment which represented a 0.43 cm/yr reduction in reservoir 3 sediment deposition. Knowing the ponds effect on reservoir sedimentation made possible determination of the reservoir sedimentation rates of 1.76 cm/yr from 1964 to 1982 and 1.33 cm/yr from 198 19922o t sedimentatioe Th . nperioe ratth n edi before 1964 (1954o t cm/yr5 19642. s .)wa

3.3.2. Precipitation and sedimentation

Precipitation records for the Pauls Valley Lake area indicated considerable variation among year se precipitatio (FigurTh . e4) n from 195 4196o t botd w 4ha h lo hig d han extremes with an overall average of 4.1 cm/yr below the long-term average of 84.3 cm/yr. There were drought r smor fo durin t e e periothano gth t time a e yeana d bu t Th a r . precipitation from 1964 to 1982 was almost average with an overall average of 0.5 cm/yr below the long-term average. The third period from 1982 to 1992 had both high and low extreme averaged san d 15.4 cm/yr abov long-tere eth m average woult I . e d th hav d eha greatest potential for sediment production from the standpoint of amount of precipitation. No long-term trend in precipitation was found which corresponded to the changes which occurre reservoidn i r sedimentation.

3.3.3. Land use

Land use at Pauls Valley Lake was divided into the same six categories as at Tecumseh Lake. The major land use changes which occurred were in abandoned and cultivated fields being replaced by perennial pasture. The greatest change occurred in abandoned field areas which were reduced from occupying 21 percent of the watershed hi 1956 to 2 percent in 1992. Cultivated fields were reduced during the same time from occupying 12 percent of the watershed to 0.5 percent.

Little change occurred in areas devoted to other land uses. Forested land accounted for abou percen 8 twatershe e th f o t d from 195 199o 6t miscellaneoud 2an percent1 e sus . A total of 5 ha of suburban use was first present in aerial photographs in 1 969 but did not expand further.

107 As at Tecumseh Lake, only two land use categories, abandoned and cultivated fields, were considered significant sediment sources. Potential sediment productio s determinenwa d for cultivated and abandoned fields in years land use was measured (Table II). In the abandoned fields, 24 km of main stem gullies 4 m or greater in width were measured. The amoun potentiaf o t l sediment productio aread n an field n si s were relate averagdo t e annual reservoir sedimentation using linear regression e relationshiTh . p between reservoir sedimentatio field nan d aresignificans awa 0.0e th 5 t a tleve explained an l percen7 d8 f o t the variabilit n reservoii y r sedimentation e relationshiTh . p between reservoir sedimentatio potentiad nan l sediment production from field s significanwa s e 0.0th 5t a t level and explained 79 percent of the variability in reservoir sedimentation. The results indicate land use could be linked to sedimentation in Pauls Valley Lake.

1950 1960 1970 1980 1990 2000 YEAR

FIG. 4. Annual precipitatio Paule th r sn fo Valle y Lake watershed. Average annual precipitatio . 84.ns i cm 3

Tabl . AreeII a use Paul fielde r dth fo n ss o Valle y Lake watershed, potential sediment from fields, and reservoirs sediment deposition.

Year Field Area Potential Sediment Reservoir Cultivated Aband. Cultivated Aband. Sediment Gullied Guilied Deposit*

______J^ ______g M — Mg/yr 56 673 1,171 15,546 423,902 37,500 63 333 598 3,846 188,963 26,400 69 165 388 1,906 130,255 26,400 79 65 212 751 66,670 26,400 92 30 126 347 60,270 19,950

* Average annual deposition for the period a year is in. The rate for 1963 was considered the same as 1964.

108 4. SUMMARY

Linking reservoir sedimentation quantitatively to long-term agricultural land use was accomplished using two approaches depending on whether sediment retention ponds had been built above a reservoir or not. The approach to determine reservoir sedimentation where retention ponds had been built was to combine 137Cs techniques with direct measurement techniques for sedimentation in retention ponds. The approach where retention ponds had not been built was to determine reservoir sedimentation through Cs 137 techniques e approacTh . h where retentio t nbee no pond nd buils useha s o wa t d investigate Tecumseh Lake decreasA . reservoin i e r sedimentatio percen3 8 f no t a t Tecumseh Lake was related to a decrease in cultivated land from 59 to 1 percent of the watershed e approacareaTh . h where retention pond d beeha sn buils useo wa t dt investigate Pauls Valley Lake. The twelve constructed retention ponds reduced reservoir sedimentation by 24 percent and a decrease in cultivated and abandoned gullied fields from 34 to 3 percent of the watershed area further decreased sedimentation by 30 percent. The two approaches make possible the quantitative determination of the effect of past land use on reservoir sedimentation.

ACKNOWLEDGEMENTS

The author appreciates the assistance of M. Yamamoto and W. Troeger with sample collection authoe Th . r thank Mea. sE preparatior dfo Kit. figure e typinr D th e fo f d no san g the manuscript

REFERENCES

[1] KELLY, L.A., Erosion-Deposition Linkages In Small Pennine Lake-Catchment Ecosystems. Ph.D dissertation, Univ. of Manchester, Manchester, U.K. (1989). [2] DAVIS , M.B., Erosion rates and land use history in southern Michigan, Environ. Conserv. 3(1976)139-148. [3] BIRCH, P.B., BARNES, R.S., SPYRIDAKIS, D.E., Recent sedimentation and its relationship with primary productivit n foui y r western Washington lakes. Limnol. and Oceanogr. 25.2 (1980) 240-247. [4] SEGERSTROM, U., RENBERG, L, WALLIN, J.E., Annual sediment accumulatio land e historynan dus ; investigation f varveso d lake sediments, hit. Assoc. of Theor. and Applied Limnol. Proc. 22 (1984) 1396-1403. [5] HEIJNIS, H., BERGER, G.W., EISMA, D., Accumulation rates of estuarine sediment in the Dollard area: Comparison of 21 OPb and pollen influx methods, Netherlands Journal of Sea Res. H (1987) 295,301. ] [6 STALL, J.B., LEE, M.T., Reservoir Sedimentatio s Causeit d Illinoisn i snan . Water Resour. Bull(19805 6 .1 ) 874-880. ] [7 U.S. Departmen Agriculturef to . Soil Surve Pottawatomif yO e County, Oklahoma, USDA Soil Conserv. Serv. U.S. Govt. Printing Off. 1977-215-229/10(1977). [8] MCHENRY, J.R., RITCfflE, J.C., COOPER, C.M., Rates of recent sedimentation in Lake Pepin. Water Resour. Bull. 6 (1980) 1049-1056. [9] GEE, G.W., BAUDER , Particle-sizW. . ,J e analysis Method: In , Soif sO l Analysis.- A. Klute (ed). Part 1,2nd Edition, Agronomy 9 (1986) 383-411.

109 [10] U.S. Departmen Agriculturef o t , Soil Conservation Service, Estimating Soil Loss Resulting From Water And Wind Erosion In Oklahoma, U.S. Govt. Printing Off. 1976-771-765/64(1976). [11] Agricultural Statistics Board. Oklahoma Crop Year County Estimates. Okla, Dept Agricf .o U.Sd . .an Dept Agricf .o . Oklahom 934-1986)a1 ( City . ,OK . [12] KRISHNASWAMY, S., MARTIN, J.M., MEYBECK, M., Geochronology of lake sediment, Earth Planet Sei. Lette . (1971r11 ) 407-414. [13] LARSEN, R.J., Worldwide Deposition Of Sr-90 Through 1983. Environmental Measurements Laboratory, U.S. Energf Depo . y Rep. EML-430 (1984). [14] National Oceanic and Atmospheric Administration, Climatological Data Oklahoma, Nat. Clim. Data Center. Asheville, NC. (1934-1992). [15] WELKIN, D.C., HEBEL, S.J., Erosion redeposition, deliver sedimenf yo o t Midwestern streams, Water Resources Research (19824 £ ,! ) 1278-1282. [16] U.S. Departmen Agriculturef to , Soil Surve Garvif yO n County, Oklahoma, USDA Soil Conserv. Serv. U.S. Govt. Printing Off. 1985 0-440-946 QL3 (1985). [17] U.S. Departmen Agriculturef to , Soil Conservation Service, Guido eT Sedimentation Investigations. Engineering Technical Not (1976)1 e70 .

110 137Cs USE IN EROSION AND SEDIMENT DEPOSITION STUDIES: PROMISES AND PROBLEMS

. RITCHIC . J E USDA ARS Hydrology Laboratory, Beltsville, Maryland

C.A. RTTCHIE Laurel, Maryland United State Americf so a

Abstract

A quarter century of research has shown great promise for using 137Cs to study erosion

and sediment deposition but it has also shown problems related with the technique. Most of the Cproblem s t uniqul37 sam e technique no th th e e o e st ar problemar t ebu s thafacee ar t d when studying erosion and sediment deposition by other techniques (i.e., sampling, measurement).

Other problems are similar to those of any chemical tracer study. While the chemistry of I37Cs is well documented, the chemistry of environments into whicChs 137 is moving is not well understood and often changes. As a better understanding of the chemistry of environments is gained then better predictions of the reaction of Cs in these environments can be made.

Probably the only truly unique problem with 137 137Cs is radioactive decay. By working to understand and control the limitations of usinCgs137 to study erosion and sediment deposition, we can improve on a technology that can provide unique information about the landscape. This information will help to develop better plans to conserve the quality of the landscape. The Cs technique may be the only way in many cases to get actual measurements of soil loss and 137 redeposition. As such, research should continue on the development of the technique so that it can be used more extensively to understand erosion on the changing landscape. .

1. INTRODUCTION

Soil erosio naturaa ns i lsoil s procesa d , rain ol wind d s sa an , . Man-induced accelerated soil erosio bees nha n shown (using radionuclide dating techniques havo )t e beene th par f o t landscap centurier efo s [1]. Soil erosio off-sits it d nean damag majoa e ear r concern aroune dth world magnitude Th .proble e concere th th f eo d mnan abou degradatioe th t landscape th f no e are well documented [2,3,4,5,6,7,8,9]. The economic damages from soil erosion along with the off-site, downstream damage from eroded soil have also been documented [7,10,11].

While it is well documented that soil erosion is a problem, there are few methods to determine actual soil erosion rates and location and subsequent sediment deposition across the

111 landscape. Field measurements of soil erosion and sediment deposition using classical techniques are difficult, time consuming, and expensive [12]. Many empirical and theoretical mathematical equations/models have been developed to estimate soil erosion. The most widely e Universauseth s i d l Soil Loss Equation (USLE) whicempirican a s i h l based equation developed with data collected from soil erosion plots on "typical" soils of the United States east of the Rocky Mountains [13]. The USLE has been used and misused in the United States and aroun Worle dth d [14]. However stils mosi e t th li , t widely used, powerfu practicad an l l tool for estimating shee rild lan t erosiolandscape th n no e [15] ReviseA . d Universal Soil Loss Equation (RUSLE) is currently being implemented in the United States which has applications widea o t r rang conditionf eo locationd san s tha originae nth l USLE [15].

Developmen s currentli t y underwageneratiow ne a n f ysoio no l erosion prediction technology. The Water Erosion Prediction Project (WEPP) is an effort to develop a process- base, simulation mode f soio l l erosion [16]. Current versions (fiel basid an d n scalee th f o ) model have been tested with the goal of fully implementing this technology to replace the USL n conservatioi r RUSLEe o us r Efo n plannin d assessmenan g y 1995b t . There ar e numerous other effort modeo t s l soil erosio off-sits it d nan e effects [17] that hav varyind eha g degrees of success and applications in management and research.

Soil erosion models have been implemente used managery dan db plannerd an s o st estimate soil erosion rates, to plan conservation practices for controlling soil loss, to inventory and assess soil erosion on regional and national scales, and to develop and implement policy decision relative to the conservation of soil across the landscape. While soil erosion models provid wealtea usefuf ho l informatio relativn no e potential soil erosion rates under different climate managemend san t scenarios providt , no the o actuayn d ea l measur ratee th r o sf eo locations of soil erosion on the landscape.

Actual soil erosion fro catchmenmeasurema e sita b r eo o t s interpreter do ha t d based fieln o d studies. Field measurement techniques involve field surveys, soil profile studies, stream monitoring, and associated techniques. These techniques are time consuming, often requiring reference data sets befor conclusioy ean made b n e mos n ca [18]I .t places around worlde th , reference data set r streaso m sediment transpor t availablt no dat e aar tha o w es ne t studies have to be started to measure soil erosion and sediment transport before conclusions can be drawn thus delaying conservation planning.

Ove e lasth rt quarter century, researchers have been studyin potentiae gth f usino l g natura man-madd an l e radioisotope o studt s e erosioyth d sedimenan n t deposition cycle. Several radioisotopes have been used. This paper is limited to a discussion of the use of radioactive fallout 137Cs to study soil erosion and sediment deposition. The potential for using fallout I37C provido st e independent measurement actuaf so l soil erosion rate patternd san d san sediment deposition is well documented [19,20,21,22]. The purpose of this paper is to review potentiae th usinr fo l g 137C studo st erosioe yth sedimend nan t deposition discus o cyclt d ean s some of the problems that have been associated with using 137Cs. A bibliography of 137Cs research related to the study of the erosion and sediment deposition cycle is provided in another sectio thif no s report 100e 0 Th . papers demonstrat extensive eth thif o se techniqueeus .

112 2. BACKGROUND

160 There are no natural 137 sources of 137Cs in the Global Depositios C f no environment; yet, 137Cs i s ^H Northern Hemisphere now globally distributed i Souther•• n Hemisphere acros earth'e sth s surface edu to deposition from « atmospheric nuclear weapon I S d testreleasean s s from t) nuclear reactors [23,24]. 3 Releases prio 195o t r 2 were 60 localized around weapon test sites or reactors [25]. With the advent of high-yield thermonuclear weapons testin n Novembei g r 1952 "ill 137 1954 I 1958 I 1962 ; 1966 I 1970 1974 ! 1976 | 1982 1986 , 1990 [26], Cs was injected into 1956 I960 1964 1968 1972 1976 1980 1984 1988 Year the stratospher circulatd ean e

globally [27]. Figur Globa. e1 l fallouCs137 (Playforf o t . 1992al t de ) It is slowly moving back to the troposphere and is subsequently deposited on the earth's surface. Robbins et al. [28] estimates that the first measurable global fallout in the northern hemisphere of I37Cs occurred in 195 years2 2± . Annual rate movemenf so f 137o t Cs frotroposphere mth earth'e th o et s surface (Fig. 1) are related to the number and size of weapon tests. Regional patterns and rates of fallout are linearly related to precipitation in latitudinal zones [27,29]. However, in a study locae ofth l variatio fallouf no t landscapee th Cn so , [30. Kisal t s]e concluded accurate local I37 determinatio f backgrouno n d s essentiaCwa s r erosiofo l n studies. . Noli[31al t e n]

concluded that at least 5I37 samples were needed to get an accurate estimate of the background Ceastern levei s 137 f o l n Canada. Other studies have reinforce e nee th dmako dt e local measurements of fallout at undisturbed sites rather than extrapolating values from fallout measurements made at another location. Total fallout Cs in the northern hemisphere is 3 to 4

times greater than fallout in the southern hemisphere [32] 137 . Fallout rates also tend to decrease as one moves away fro temperate mth e zone. Rate f fallouso Cst 137 have decreased since eth maximum in the early 1960's with fallout since the mid 1980's often being below detection levels [24]. Releases from nuclear reactors are usually local in nature, however unique events, such as the Chemobyl accident in April 1986, can cause regional dispersal of measurable Cs 137 [33] thaimpacn ca t t (Fig totan o ) l. 1 global deposition budget [32]. Thus man's activities relate nucleao dt r energy have distribute uniquda e radioactive chemical element acrose sth landscape surface in uniform patterns that can be used to trace natural events.

The chemistry of this unique tracer is well understood [29,34]. Once 137Cs reaches the soil surfac s strongli t i ed quicklan y y adsorbe e clath y y particleb d s essentiall i d an s y

nonexchangeabl mosn ei t environments [35,36,37,38,39]. Thus 137Cs become effectivn sa e movemene traceth f o r f surfaco t e soils. Distributio Csoin si 137 f ln o profile undisturbet a s d sites show exponentian sa l decrease with depth [20,40,41,42,43] while plowed soils showa uniform distribution throughou plowee th t d layer [44,45,46,47]. Lese th C sf s s i o tha % n1 137

113

flushed fro mcatchmena solution i t n immediately after deposition generalld an , y less than 0.1% moves in solution per year after the initial flush [48,49,50]. Thus most movement Cosf 137 acros landscape physicaso th t e du s eli processes which redistribute soie l th particlee ar d san same physical processes of the erosion and sediment deposition cycle.

Since accurately measuring Cs in environmental samples is relatively easy [51,52], 137 the challenge for those interested in soil erosion and sediment deposition is to study the

LU! SOURCE (MAN'S ACTIVITIE NUCLEASN I R FISSION) ce LU 137 ! Cs DEPOSITIONAL POOL

MOVEMEN PRECIPITATIOO T E DEPOSITIOY TDU DR D N N / N

WASF HOF SOILS TURN OVER 1

' 1 REDEPOSITION UPTAKE

LAND SYSTEMS WATER SYSTEMS Figure C2.s 137 landscape e cyclth n eo .

changing pattern distributiof so n (Fig137f o C) .s2 tagged soil particle landscapee th n so e Th . redistribution of Cs between and within landscape elements provides information on soil 137 erosion ratepatternsd e an vegetatios Th . n contributio e redistributioth o nt f o n Cs i s negligibl mosn i e t systems [53,54,55,56]. Thi especialls i s137 y true with reduced rate fallouf so t d 1960'smi sinc e . th e Most 137Cs cyclin plantn i g s beeha sn relatee founb o t dleao dt f interceptio f fallou nwateo soid e th an l rtn i compartment137 s i Cs t I . s where measurementf so Cs movement between and within landscape compartments can contribute to the understandin137 soie th l f erosiogo sedimend nan t deposition. Although biologica chemicad an l l processes move limited amounts 137C uniqun si e environments, physical processe watef so d ran wind are the dominant factors moving 137Cs tagged soil particles between and within

compartments landscape. The following discussion will focus on water related movements of Cs 137 tagged particles. Howeve mann o r y area earth'f so s surface majoe th ,e rwinb facton dca r moving soil particle associated san d 137Cs.

EROSIO. 3 N STUDIES

Several early studies on the movement of radionuclides across the landscape found a relationship between soil losradionuclidd san e loss from plot studr so y areas [57.58,59,60,61]. These studies indicated that radionuclides were moving with the eroding soil particles and thus

114 measurements of soil movement could be used to estimate radionuclide movement or redistribution in an area. Most studies indicate that 137Cs does not move in solution under most soil (landscape) conditions [35,38]. However studie organicf so , peat acid an d, soils have shown movemenf o t Csolution i s surfaco t n e runof r througo f e soihth l profile [62]. 137 However such soluble movement is limited to unique soil conditions. Depth distribution in soil profiles has been linked to particle size distribution, organic matter [63], and the amount and type of clay present [35]. . Ritchial [64 t e e] combine resulte dth earlf so y studies with their study of 100 137 Cs loss e relateth o t d j A -Loughran et al. 1988 USLE estimated soil loss. 9C Ritchi- B McHenrd ean y 1975 Using this mixtur f dato e a (different radionuclides, different size source areas, different time periods, 3 erosion), they developen da empirical equation that showed a significant exponential relationship between measured soil loss and radionuclide loss. Others [65,66,67] have found similar exponential equations. Empirical 0.01 0.1 1 relationships, while SOIL LOSS (t/ha/year) importan demonstratinn i t ga Figure 3. Empirical models of soil loss vs. 137Cs loss. relationship between soid lan 137Cs loss, have many limitations e empiricaTh . l equations of Loughran et al. [67] developed with Southern Hemisphere data and Ritchie and McHenry [68] developed with Northern Hemisphere data are shown in Figure 3. While the general for thesf mo e equation the) yX similaa s givsi = e Y largr( e difference estimaten i s d erosion rates. Such empirical equation affectee sar climatey db , soils, time since fallout, time period of development, and other landscape and environmental factors. Thus there are many valid reason differencee th r sfo equation i s (SouthernA n Hemisphere (NortherB data d )an n Hemisphere data) show Figurn i . eFigur3 illustratee3 problee sth f mapplyino g empirical based equatio differeno nt t data sets. Similar concern applicatioe th r sfo misusd e nan th f eo empirical based USLE have been expressed [14]. Empirical equations are applicable only to the rang conditiond ean date th af suseo thein di r development. Using this approac estimato ht e soil will require the development of an empirical equation (calibration curve) for each site or at best, for each region. Empirical equations are dependent on the time since and time of fallout. While these empirical equations may help explain and better define the role of different factors that affect the relationship between soil loss and radionuclide loss, the many limitations to their application reduce their usefulnes estimatinr sfo g soil larglosa n so e scale.

seconA d approac usinr hfo g 137C studo st y erosio assumo t s ni e tha lose 137f tth s o Ct sa a site is directly proportional to the loss of soil. The simplest form of this approach is to equate

115 soil loss to 137Cs loss (Y=X), where Y is soil loss in weight per area per time and X is 137Cs los percenn si weightr o t . Suc hrelationshia publishes pwa Vandey db n Bergh Gulincd ean k [69]. However such direct proportional relationship raree mossn ar I . t published reportsX e ,th term is modified by depth distribution of 137Cs, density of soil, decay corrections, and other coefficients and modifiers [22]. Kachanoski [70] provided an empirical verification of this approach by measuring 137Cs concentrations in erosion plots at two different times and comparin resulte gth measuref so d soil loss fro plote mth s with measured 137Cs loss majoA . r assumption with this technique is that I37Cs is instantaneously uniformly distributed hi the soil profile. Since 137Cs is deposited on the surface soil and strongly adsorbed, it requires mechanical mixing (plowing) to achieve this uniform distribution. Thus during times of fallout these conditions are seldom met leading to excess removal of 137Cs with surface erosion, causing overestimation of soil loss. The original proportional approach was limited to cultivated land since 137Cs has an exponential decrease with depth at undisturbed sites. However, Zhan . [71al ]t ge develope techniquda adaptinr efo principle gth proportionae th f eo l approach to non uniformly distributed 137Cs in soil profiles at undisturbed sites. Since fallout and erosio bote nar h relate rainfallo dt , ther concerne ear s about erosion rates during timef so heavy fallout. During these times, greater erosion rates would remove proportionally more 137Cs fro surface mth e laye thusoif d ro lan s lead overestimatioo st lonf no g term erosion rates. This proble mmagnifies i therf di indicatione ear s that erosion rates were significantly higher during times of maximum fallout and removed a disproportional amount of the fallout. In genera proportionae lth l method will probably overestimate actual erosion rates for time periods that involve heavy fallout. The proportional method will probably reflect actual erosion rates when an area is cultivated that had been undisturbed since the mid 1950's.

Another approach, similar to the proportional method, is to determine balances between depletion and accumulation areas of 137Cs on a catchment. By determining a 137Cs balance for a catchment spatiae ,th l patter losd 137f nsan o Cs fro catchmene mth calculatede b fielr to n dca . Such studies thus allow an understanding of erosion and deposition patterns of soil particles. Such approaches have been used [71,72,73,74,75] to study erosion and deposition patterns on the landscape. These techniques give qualitativ wels ea quantitativs la e informatio erosion no n patterns. As with the other techniques, the balance approach requires a determination of the

baseline level of 137Cs for the study area. Several studies have cautioned against using fallout measurements to estimate totaCsl137 loads in soils of a watershed. Measurements of actual 137Cs shoul made dnonerodinb a t ea catchmentge sitth n ei compariny B . g 137Cs measurement at a study site with the baseline level one can determine whether erosion (less 137Cs present than at the baseline site) or deposition (more I37Cs present that at baseline site) has occurred. The balance approach use proportionasa l relationship between erode noneroded dan d sites. McHenry and Bubenzer [73] used this technique to estimate erosion on a Wisconsin catchment and fountime0 10 d s o t mortha 0 5 t e redeposites soiwa l d withi nfiela d tha moves f o nt wa dou the field.

Walling and Quine [22] compared different balance equations and found different assumptions lea differeno dt t result eacr sfo h approach. Simila e otheth o rt r approacher fo s studying erosio balance nth e approac onls hi realistis ya assumption e th s ca modeld san s used. As with the other approaches, the timing of the fallout and erosion events is critical. If 137Cs loss is not uniform with time (i.e. greater loss shortly after deposition) then erosion will be overestimated. If soil loss is not uniform in space then budget approaches will underestimate soil loss. These limitations tend to reduce the absolute accuracy of using 137Cs to estimate erosion.

116 Walling and Quine [22] have discussed future needs for improving the use of 137Cs to estimate erosion. Their suggestions included 1) long term erosion plot studies to derive better understanding groune th f so d truth/calibration relationships improve) ,2 d theoretical modelr sfo the development of budget approaches, and 3) better physically based improvements in the understandin erosionae th f go l los 137f so C thao ss t budget bettee b n rsca modeled .

While there are limitations to the use of fallout 137Cs to estimate erosion, these

limitations are no greater than those associated with other techniques for studying erosion. Campbell et al. [76] suggest that the errors of Cthse 137 technique may be less than current techniques used by soil scientists and geomorphologists to study erosion. If we understand the limitations and design studies to minimize the effects of these limitations on measurements then measuring the concentration of 137Cs across the landscape can provide accurate and valuable informatio erosionn no .

4. SEDIMENT DEPOSITION The general principle for the applicationC osf 137 for studying sediment deposition is to relate the depth distribution of the concentration of 137Cs in a sediment profile to the temporal pattern of atmospheric deposition of fallout. Records of the temporal patterns of fallout are available or can be calculated for most parts of the world [23,24]. Initial input of global fallout estimates i 195e b year 2 o d2t ± s [28] with measurable amount soie th l beginninn si 195n gi 4 [19,20,27]. In the northern hemisphere, the temporal pattern of fallout shows major fallout peaks in 1958/1959 and 1963 (Fig. 1) with significantly reduced levels during 1960 and 1961 and a general decrease since 1963 to levels below detection by the mid 1980. Major periods of fallout can be related to atmospheric nuclear weapon tests [25] with periods of reduced fallout relate moratorio dt e Testh tr ao Ban d Treat f 1963yo . Campbell [20 s reporte]ha d similar patterns of fallout for the southern hemisphere with slight shifts in dates and significantly less total fallout [32]. The Chemobyl accident introduced a significant spike of activity for a large area of Europe and Asia. Thus there are potentially 4 temporal markers (1954, 1958/1959, 1963, 1986) for sediment profiles. The 1954 and 1963 markers are usually detectable hi most profiles.

Input of Cs to sediment profiles is from direct deposit at the site or by deposition of 137 erosional particles fro catchmente mth . Uptak 137f eo C waten si r bodie suspendey sb d particles watee inth rapis ri d [77,78] residence Th . e tim thesf eo e suspended particle waten si shors ri t smaln i mediud an l m size lake thud san s their deposition pattern reflect time sth e distribution patter 137f no Cs deposition fro atmospheree mth largei h , r lakes residence th , e tim thesf eo e particles and, therefore, the 137Cs, can be significantly longer and cause a time differential between the time of deposition on the lake surface and their deposition on the sediment surface [79]. Stiller [80] points out, the source function does follow the fallout pattern as fallout rates have decreased since 1964. Thu muse son t consider bot residence hth source eth timd eean function when assigning dates in sediment profiles. Ritchie et al. [81] estimated the time lag to be 6 to 12 months for several small reservoirs. However, the actual time will depend on the environmental conditions in each lake [19]. Edgington et al [79] used these time differentials in 137Cs deposition to estimate residence time in Lake Baikal. Walling et al. [82] also suggested that these deposition rates could be used to measure residence time.

117 Concentrations of 137Cs in the 1954 sediment profile level are often near or below

detection levels and can cause inaccuracies in measuring 137Cs at that level. Radioactive decay continue reduco st environmene amoune th C eth n si 137 f o t t thus further limitin accurace gth y of the detection of the 1954 level. This is especially critical in the southern hemisphere where fallout levels were lower [20].

Reworking of bottom sediments by biological and physical processes tends to spread 137Cs fro originas mit l poin depositiof o t profilea n ni . Numerous studies have documented such movement [83,84,85,86,87,88,89,90,91,92,93,94]. hi general reworking, whether biologica r physicalo l , broadene sth C s peaks. However, such reworkin t likelno s o gyi t 137 change the actual position of the peak [19,20,81,85,95,96,97] only to spread it. This spread become concersa n when tryin determino gt firs e levee th et th f inpuo l 137f o t C 195n si 4 since downward reworking would caus overestimatea f depositioeo n rates. Als w arean oi lo f so sediment deposition lowee th ,rat e sedimenf rth eo t depositio greatee nth effece rth t reworking has on the Cs dating, again causing an overestimate of sediment deposition. 137 Chemical diffusion can redistribute 137Cs in a profile. Although most environmental chemical activity that affects 137Cs is limited [24,35,98,99], it can occur under some environmental conditions [100,101,102]. Again such movement is not likely to change the position of the peak, only spread it out. As with reworking, the greater problems would be caused for the detection of the 1954 level and hi areas of low sediment deposition.

Particle size distribution of the sediment profile must also be considered when

137

interpretinCs 137 profilega . SincC associates sei d wit finee hth r sized soil particlesn a , increase in sand sized particles will cause an apparent decreaseC osf 137 that can not be related atmospherio t c fallout rates expressiny B . g functioa Cs sa claf sild no ty an concentration , the variations due to particle siz e137 distribution can be minimized.

Samplin problemalsa n ge ca o b depositio w areayr~*)n lo I m . c f so 1 , samplin< n( f go horizons small enough to defineC sa 137 profile is difficult. There are also problems with sampling techniques. Most sediment samplers tend to carry sediment with them as they move throug profilee hth . Thi distributn sca e 137Cs much deepe profile th caus d n ri e an e problemn si the interpretations of the profile.

While 137 providn Csca e valuable informatio f depositionano l profiles amoune th , f o t information is limited. Only 2 horizons (1954 and 1963) can be detected consistently. The detectio e 1954th f no profil alss ei o becoming more difficul determino t t e accuratelo t e ydu

radioactive decay. The Chernobyl accident has labelled a new horizon in some parts of the world. Thu usefulnese sth providinCn i s137 e datinf b future o sy th gmarken a gma ei r with whic helho t calibratpo t e other dating techniques.

5. SUMMARY

A quarter centur researcf yo shows hha potentiae nth usinr fo l g C studo st y erosion sedimend an t depositio alss ha o t i indicate t nbu d problems related wit techniquee h137th . Mosf o t probleme th t uniqu 137e no th Ce so essamar t e techniquth e ar problem t ebu s thafacee ar t d when studying erosio d sedimenan n t depositio y otheb n r techniques (i.e., sampling, measurement). Other problem similae sar chemicay thoso rt an f eo l tracer study. While eth

118

137 chemistrC wels si 137 f lyo documented chemistre th , f environmentyo s into whicCs hsi

moving is not well understood and often changes. As a better understanding of the chemistry of environments is developed then better prediction of the reactionC osf 137 in these environments madee b n . ca Probabl e onlyth y truly unique problem with 137 Cs radioactivi s e decay. Understandin controllind gan limitatione gth f usinso g I37C studo st y erosio sedimend nan t deposition will improve a technology that can provide unique information about soil movement landscapee th n o . This technology will lea plannino dt g techniques than conservca t e eth quality of the landscape. The Cs technique is often the only way in many cases to get actual 137 measurements of soil loss and redeposition. As such, research should continue on the development of the technique in an effort to better understand the changing landscape.

REFERENCES

] [I O'Hara, S.L., Street-Perrott, F.A., Burt, T.P., Accelerated soil erosion aroun dMexicaa n highland lake cause prehistoriy db c agriculture, Nat(19932 36 . )48 ] [2 Walling, D.E. sedimene ,Th t delivery problem . Hydrol,J . 6_5_ (1983) 209. [3] Brown, L.R., Wolf E.G., Soil erosion: Quiet crisis in the world economy, Worldwatch Pape (1984i r£f ) 51pp. [4] Plimentel, D., Alien, J., Beers, A., Guinand, L., Linder, R, McLaughlin, P., Meer, B., Musonda, D., Perdue, D., Poisson, S., Siebert, S., Stone, K., Salazar, R., Hawkins, A., World agriculture and soil erosion, Biosci. 3_7 (1987) 277. [5] Smith, R.A., Alexander, R.B., Wolman, M.G., Water-quality trends in the Nation's Rivers, Sei (1987Ü .2 ) 1607. [6] Walling, D.E., Webb, B.W., Material transport by the world's rivers: evolving perspectives, IAHS Publ (19874 J16 3 )31 ] [7 Walling. D.E., "The struggle against water erosio prospectiva d nan recenn eo t research", Water Erosion . Ivanov(K , , Pechinov , Eds.)D. , , UNESCO Technical Documenn i t Hydrology SC-89/WS-57 (1989) 39. [8] Dregne. H.E., Erosion and soil productivity in Africa, J. Soil Water Conserv. 45 (1990) 431? [9] Dregne, H.E., Erosion and soil productivity in Asia, J. Soil Water Conserv. 47 (1992) 8 [10] Clark, II, E.H., The off-site cost of soil erosion, J. Soil Water Conserv. 4Q (1985) 19. [II] Colacicco , OsbornD. , , Alt T. , Economi ,K. c damage from soil erosion . SoiJ , l Water Conserv (19894 .4 . )35 [12] Laflen, J.M., Lane, L.J., Foster, G.R, WEPP A new generation of erosion prediction technology . Soi,J l Water Conserv (1991. .46 . )34 [13] Wischmeier, W.H., Smith, D.D., Predicting rainfall-erosion losse croplanr sfo de easth f to Rocky Mountains, Agr. Handbook No. 262 (1965). USDA, Washington, DC. [14] Wischmeier misus,d universae W.H.an th f e eo Us , l soil loss equation . SoiJ , l Water Conserv. 3_1(1976. )5

119 [15] Renard, K.G., Foster, G.R., Weesies, G.A., Porter, J.P., RUSLE Revised universal soil loss equation . Soi,J l Water Conserv. 4_6_ (1991. )30 [16] Laflen, J.M., Elliot, W.J., Simanton, J.R., Holzhey, C.S., Kohl, K.D., WEPP Soil credibility experiment for rangeland and cropland soil, J. Soil Water Conserv. 46. (1991) 39. [17] Foster, G.R., Advances in wind and water erosion prediction, J. Soil Water Conserv. 46 (1991)27. [18] Brakensiek, D.L., Osborn, H.B., Rawls, W.J., Field Manual for Research in Agricultural Hydrology, USDA Agriculture Handboo (19794 22 . )k WashingtonNo . ,DC [19] Wise, S.W., "Caesium-13 lead-210d 7an revietechnique A : th f w o applicatio d ean o nt geomorphology" Timescales in Geomorphology , (Cullingford, R.A., Davidson, D.A., Lewin Eds.), ,J. , John Wile Sonsy& , London (1980) 109. [20] Campbell, B.L., Application of environmental caesium-137 for the determination of sedimentation rate reservoirn si laked related san san d catchment studie developinn si g countries, AAEC Research Establishment, Lucas Heights Research Lab., PMB Sutherland 3322, N.S.W., Australia (1982). [21] Ritchie, J.C., McHenry, J.R., Applicatio radioactivf no e fallout cesium-13 measurinr 7fo g soil erosio sedimend nan t accumulation rate patternsd san review:A Environ. J , . Quaià ,l (1990)215. [22] Walling, D.E., Quine, T.A., "Uscaesium-13f o e investigato 7t e pattern rated soif san s o l erosion on arable fields", Soil Erosion on Agricultural Land (Broadman, J., Foster, I.D.L, Dearing, J.A., Eds.), John Wiley & Sons, London (1990) 33. [23] Larson, R.J., Worldwide fallou f Sr-9o t 0 through 1983, USDOE Rep. EML-444 (1985), EML,NY. [24] Cambray, R.S., Playford, K., Lewis, G.N.J., Carpenter, R.C., Radioactive fallout in air and rain: Results to the end of 1988, U.K. Atomic Energy Authority Report AERE-R- 13575 (1990). [25] Carter, M.W., Moghissi, A.A., Three decades of nuclear testing, Health Phys. 3_3_ (1977) 55. [26] Perkins, R.W., Thomas, C.W., "Worldwide fallout", Transuranic Elements in the Environment, (Hanson W.C., Ed.), DOE/TIC-22800 (1980) 53. [27] Longmore, M.E., "The caesium-137 dating technique and associated applications in Australia— A review", Archaeometry: An Australasian Prospective, (Ambrose, W., Duerden, P., Eds.), Australian National University Press, Canberra, Australia (1982) 310. [28] Robbins, J.A., Edgington, D.N., Kemp, L.W., Comparative Pb, polleCsd an , n 210 137 geochronologie sedimentf so s from Lake Ontari Eried oan , Quat (1978. Û Res1 . ) 256. [29] Davis, J.J., "Cesium and its relationship to potassium hi ecology", Radioecology, (Schultz, V., Klement, A.W. Jr., Eds.), Reinhold, NY (1963) 539. [30] Kiss ,Jong e J.J.d , Martz, E. , distributio,e L.W.Th , f fallouno t cesium-13 southern 7i n Saskatchewan, Canada. J. Environ. Qual. 12 (1988) 445. [31] Nolin, M.C., Cao, Y.Z., Coote, D.R., Wang, C., Short-range variability of fallout Cs in an uneroded forest soil, Can. J. Soil Sei. 21 (1993) 381. 137

120 [32] Playford , LewisK. , , G.N.J., Carpenter, R.C., Radioactiv raind ean :fallou r Resultai n i t s to the end of 1990, AEA-EE-0362 (1992) 27. [33] Volchok, H.L., Chieco, N. (Ed.), A compendium of the Environmental Measurement Laboratory's research projects relate Chernobyo dt l nuclear accident, USDOE Rep. EML- 460, EML (1986Y ,N ) [34] Schultz, R.K., Overstreet, R., Barshad, I., On the soil chemistry of cesium-137, Soil Sei. 52(1960)19. [35] Tamura , Consequence,T. activitf so y release: Selective sorption reaction cesiuf so m with soil minerals, Nuci. Safet (1964y5 ) 262. [36] Tamura T., "Reaction of cesium-137, and strontium-90 with soil minerals and sesquioxides", 8th. International Congress of Soil Sei., Bucharest, Romania, (1964), 465. [37] Baltakmens , GregoryT. , , L.P., Profil 90f 137d eo S Cran s concentration selecten si w dNe Zealand soil theid san r bearin miln go k contamination levels, N.Z . Sei.J (19770 .2 ) 425. [38] Cremers, A., Eisen, A., De Prêter, P., Macs, A., Quantitative analysis of radiocaesiurn retention in soils, Nat. 335 (1988) 247. [39] Livens, F.R., Rimmer , Physico-chemicaD. , l control artifician so l radionuclide soiln si , Soil Use and Management 4 (1988) 63. [40] Beck, H.L., Environmental gamma radiation from deposited fission products 1960-1964, Health Phys (19662 .1 ) 313. [41] Ritchie, J.C., Clebsch, E.C.C., Rudolph, W.K., Distribution of fallout and natural gamma radionuclide littern si , humus surfacd an , e mineral soils under natural vegetatioe th n ni Great Smoky Mountains, North Carolina- Tennessee, Health Phys. 18 (1970) 479. [42] Ritchie, J.C., McHenry, J.R., Gill, A.C. distributioe ,Th Cs-13f no uppee th litte n 7i d r ran 10 centimeter f soiso l under different vegetation type northern i s n Mississippi, Health Phys. 22 (1972) 197. [43] Campbell, B.L., Loughran, R.J., Elliott, G.L., Caesium-137 as an indicator of geomorphic processes in a drainage system, Aust. Geographical Studies 2Û (1982) 49. [44] Cline, J.F., Richards, W.H., Radioactive strontiu d cesiuman n cultivatemi d an d abandoned plots, Health Phys. 21 (1972) 317. [45] Ritchie, J.C., McHenry, J.R., Vertical distribution of fallout cesium-137 in cultivated soils, Rad. Dat Reportd aan (19734 s1 ) 727. [46] Bachhuber, H., Bunzl, K., Schirnmack, W., Spatial variability of distribution coefficients of 137Cs, 65Zn, 85Sr, 57Co, 109Cd, 141Ce, 103Ru, 95m 131Tcd cultivaten Ii an , d soil, Nucl. Tech. 72 (1986) 359. [47] Loughran, R.J., Campbell, B.L., Walling, D.E., Soil erosion and sedimentation indicated by caesium 137: Jackmoor Brooke catchment Devon, England, Catena 14 (1987) 201. [48] Brunskill, G.J., Ludlam, S.D., Peng, T.H., Fayetteville Green Lake, New York, U.S.A. VIII. Mass balance of 137Cs in water, varved and non-varved sediments, Chem. Geol. 44 (1984) 101. [49] Eakins, J.D., Cambray, R.S., Chambers, K.C., Lally, A.E., "The transfe naturaf o r d an l artificial radionuclide o Brotherswatet s r fro s catchment"it m , Lake Sedimend an t Environmental History, (Haworth, E.Y., Lund, J.W.G., Eds.), University of Minnesota Press, Minneapolis, MM. (1984) 125.

121 [50] Heiton, J.C., Müller, A.B., Bayer, A., Contamination of surface-water bodies after reactor accidents by the erosion of atmoshperically deposited radionuclides, Health Phys. 48. (1985)757. [51] Ritchie, J.C., McHenry, J.R., Determinatio f fallouno t Cs-13 naturad 7an l gamma-ray emitting radionuclides in sediments, Intern. J. Appl. Radiât. Isotopes 24 (1973) 575. [52] McCallan, M.E., O'Leary, B.M., Rose, C.W., Redistributio f caesium-13no erosioy 7b n and depositio Australian a n no n soil, Aust Soi. .J l Sei ! (1980.lj ) 119. [53] Dahlman, R.C., Francis, C.W., Tamura, T., "Radiocesium cycling in vegetation and soil", Mineral Cycling in Southeastern Ecosystems, (Howell, F.G., Gentry, J.B., Smith, M.H., Eds.), USAEC Symposium Series, CONF-740513 1975) 462. [54] Brown, R.B., Cutshall, N.H., Kling, G.F., Agricultural erosion indicatey b dC s 137 redistribution Level. :I distributiod san f no Cs activit soilsn yi , Soil 5 Sei4 . J . Soc. Am . 137 (1981)1184. [55] Brown, R.B., Kling, G.F., Cutshall, N.H., Agricultural erosion indicate y 137b d Cs redistribution: II. Estimates of erosion rates, Soil Sei. Soc. Am. J. 45 (1981) 1191. [56] Campbell, B.L., Elliott, G.L., Loughran, R.J. Nuclear fallout as an aid to measuring soil erosion . Soi,J l Conserv Soutw .Ne h Wale (19852 s4 . )86 [57] Menzel, R.G., Transport of strontium-90 in runoff, Sei. 131 (1960) 499. [58] Graham, E.R., Factors affecting Sr-8 1-13d 5an 1 remova runofy b l f water. Wated an r Sewage Works 110 (1963) 407. [59] Rogowski, A.S., Tamura , Movemen,T. f to Crunoffy sb , erosio infiltratiod nan e th n no 137 alluvial Captina silt loam, Health Phys (19651 .1 ) 1333. [60] Rogowski, A.S., Tamura , EnvironmentaT. , l mobilit cesium-137f yo , Rad. Bot (19700 .1 ) 35. [61] Rogowski, A.S., Tamura, T., Erosional behavior of cesium-137, Health Phys. i£ (1970) 467. [62] Hilton , LivensJ. , , F.R., Spezzano , LeonardP. , , D.R.P., Retentio radioactivf no e caesium by different soils in the catchment of a small lake, Sei. Total Environ. 129 (1993) 253. [63] Dörr, H., Munnich, K.O., Lead and cesium transport in European forest soils, Water, Air, Soil Pollut. 5J7 (1991) 809. [64] Ritchie, J.C., Spraberry, J.A., McHenry, J.R., Estimating soil erosion froe th m redistribution of fallout Cs-137, Soil Sei. Soc. Am. Proc. M (1974) 137. [65] Wilkin, D.C., Hebel, S.J., Erosion, redepositio deliverd nan f sedimenyo midwestero t n streams, Water Resour. Res. IS (1982) 1278. [66] Campbell, B.L., Elliott, G.L., Loughran, R.J., Measurement of soil erosion from fallout 137Cs, Search 17 (1986) 148. [67] Loughran, R.J., Campbell, B.L., Elliott, G.L., "Determination of erosion and accretion rates using caesium-137", Fluvial Geomorphology of Australia, (Warner, R.F., Ed.), Academic Press, Australia (1988) 87. [68] Ritchie, J.C., McHenry, J.R., Fallout Cs-137 too A :conservatio n i l n research . SoiJ , l Water Conserv (19750 3 . ) 283.

122 [69] Vanden Berghe, L, Gulinck, H., Fallout Cs as a tracer for soil mobility in the landscape 137 framework of Belgian loamy region, Pédologie 12 (1987) 5. [70] Kachanoski, R.G., Comparison of measured soil 137-cesium losses and erosion rates, Can. J. Soil Sei. 67 (1987) 199. [71] Zhang X.B., Higgitt, D.L., Walling, D.E., A preliminary assessment of the potential for using caesium o estimatt 7 -13 e rate f soio s l erosioe Loesth n i sn Platea f Chinao u , Hydrological (1990Sei5 3 . .J ) 243. [72] Kachanoski, R.G., de long, E., Predicting the temporal relationship between cesium-137 and erosion rate, J. Environ. Qual. 11 (1984) 301. t j] McHenry, J.R., Bubenzer, G.D., Field erosion estimated from Cs activity measurements, Trans . SocAm . Agric. Engr (1985& 2 . ) 480. [74] Fredericks, D.J., Perrens, S J., Estimating erosion using caesium-137: II. Estimating rates of soil loss, IAHS PublJ 174 (1988) 233. [75] Quine, T.A., Walling, D.E., Rate soif so l erosio arabln no e field Britainn i s : quantitative data from caesium-137 measurements, ManagSoie lUs (19917 . ) 169. [76] Campbell, B.L., Airey, P.L., Calf, G.E., "Us isotopif eo c technique hydrologican si d an l erosion-sedimentation studies in tropical and temperate zones of the Asian-Pacific region", International Geomorphology (Gardiner , Ed.)V. , , Par . Joh1 t n Wile Sons& y , London (1987) 751. [77] Eyman, L.D., Kevern, N.R., Cesium-137 and stable cesium in a hypereutrophic lake, Health Phys. 28 (1975) 549. [78] Francis, C.W., Brinkley, F.S., Preferential adsorption of Cs to micaceous minerals in 137 contaminated freshwater sediments, Nat (19760 .26 ) 511. [79] Edgington, D.N., Val Klump, J., Robbins, J.A., Kusner, Y.S., Pampura, V.D., Sandimrnirov, I.V., Sedimentation rates, residence time, and radionuclide inventories in Lake Baikal from 137Cs and 210Pb in sediment cores, Nat. 350 (1991) 601. [80] Stiller, M., "Sedimentation patterns in Lake Kinneret (Tiberias)", Isotopes hi Lake Studies, IAEA Advisory Group meeting, AugSept2 - 9 .. 2 1977 (1977) 273. [81] Ritchie, J.C., McHenry, J.R., Gill, A.C., Dating recent reservoir sediments, Limnol. Oceanogr (1973& .1 ) 255. [82] Walling, D.E., Bradley, S.B., Wilkinson, C.J., A caesium-137 budget approach to the investigatio sedimenf no t delivery fro msmala l agricultural drainage basi devonn i , ,UK IAHS Publ.# 159 (1986) 423. [83] Robbins, J.A., Edgington, D.N., Determination of recent sedimentation rates in Lake Michigan using Pb-210 and Cs-137, Geochim. Cosmochim. Acta 12 (1975) 285. [84] Robbins, J.A., McCall, P.L., Fisher, J.B., Krezoski, J.R., Effec f deoosio t t feedern o s migration of 137Cs in lake sediment, Earth Plant. Sei. Lett. 42 (1975) 277. [85] Robbins, J.A., Krezoski, J.R., Mozley, S.C., Radioactivit sedimentn yi e Greath f to s Lakes: Post-depositional redistribution by deposit-feeding organisms, Earth Plant. Sei. Lett é (1977l , ) 325. [86] Hâkanson , KällströmL. , equation A , f statA. , n o biologicallr efo y active lake sediment and its implications for interpretations of sediment data, Sedimentologv 21 (1978) 205.

123 [87] Krezoski J.R., Mozley, S.C., Robbins, J.A., Influenc f benthio e c macroinvertebraten so mixin profundaf go l sediment southeastern si n Lake Huron, Limnol. Oceanogr (19781 .2 ) 1011. [88] Krezoski, J.R., Robbins, J.A., Vertical distributio f feedino n particle-selectivd an g e transporf o t Clakn i s e sedimen lumbriculiy b t d Oliqochaetes . GeophyJ , . ResÛ 2 . 137 (1985)11999. [89] Fisher, J.B., Lick, W.J., McCall, P.L., Robbins, J.A., Vertical mixin f lakgo e sediments by tubificid Oligochaetes, J. Geophy. Res. £5. (1980) 3998. [90] Kacieszczenko, J., Banasik, Z., An effect of bioturbation on the results of the 137Cs dating technique used for lacustrine sediments, Ekologia Polska 29 (1981) 615. [91] DeMaster, D.J., McKee, B.A., Nittrouer, C.A., Brewster, D.C., Biscaye, P.E., Rates of sediment reworkin Hebble th t ga e Site base measurementn do Th-234f so , - Cs-13Pb d 7an 210, Marine Geol (1987. 66 . ) 133. [92] Robbins, J.A., A model for particle-selective transport of tracers in sediment with conveyors belt deposit feeders . GeophyJ , . Res (19861 9_ . ) 8542. [93] Anderson, R.F., Schiff, S.L., Hesslein, R.L., Determining sediment accumulation and mixing rates using Pb, Cs and other tracers: Problems due to postdepositional 2IO 137 mobility or coring artifacts, Can. J. Fish. Aquat. Sei. 44 (1987) 231. [94] Sharma , GardnerP. , , L.R., Moore, W.S., Bollinger, M.S., Sedimentatio bioturbatiod nan n isalna t mars reveales ha y db Pb studiese , 'B d Csan , Limnol. Oceanogr (19872 .1 ) 210 137 313. [95] Krishnaswamy, L.K., Lal , Martin,D. , J.M., Maybeck , GeochronologM. , f lako y e sediments, Earth Plant. Sei. Lett. 11 (1971) 407. [96] Pennington Cambray, ,W. , R.S., Eakins, J.D., Harkness, D.D., Radionuclide datine th f go recent sedimen Blelhai th m Tarn, Freshwater Biol (1976.& ) 317. [97] Pennington Cambray, W. , , R.S., Fisher, E.M., Observation lakf so e sediment using fallout 137Cs as a tracer, Nat. 242 (1973) 324. [98] Aston, S.R., Duursma, E.K., Concentration effects of 137Cs, 65Zn, 60Co, and 106Ru sorptio mariny nb e sediments with geochemical implications, Resa Neth Se (1973. . 6 J . ) 225. [99] Lomenick, T.F., Tamura Naturall, T. , y occurring fixatio f cesium-13no sedimentn 7o f so lacustrine origin, Soil Sei. ProcSoc. (19652 Am .. 2 ) 383. [100] Evans, D.W., Alberts, J.J., Clark, R.A. III, Reversible ion-exchange fixatio f cesiumno - 137 leadin mobilizatioo gt n from reservoir sediments, Geochim. Cosmochim. Act7 a4 (1983) 1041. [101]Davis, R.B., Hess, C.T., Norton, S.A., Hanson, D.W., Hoagland, K.D., Anderson, D.S., d CPsan b datin sedimenf go t from soft-wate Englanrw lakeNe n si d (U.S.A.d )an 137 210 Scandinavia, a failure of Cs dating, Chem. Geol. 44 (1984) 151. I37 [102] Torgersen , LongmoreT. , , M.E., Cs diffusio e highlth n i yn organic sedimenf o t 137 Hidden Lake, Fraser Island, Queensland, Australian J. Marine Freshwater Res. 35 (1984) 537.

124 BIBLIOGRAPH PUBLICATIONF YO F 137SO CESIU M STUDIES RELATEO DT EROSION AND SEDIMENT DEPOSITION*

J.C. RITCHIE USD HydrologS AAR y Laboratory, Beltsville, Maryland

C.A. RITCHIE Laurel, Maryland

United State f Americso a

1. INTRODUCTION

Soil erosios subsequenit d nan t redeposition acros landscape sth majoa s ei r concern around worlde th quarteA . r centur researcf yo shows hha n that measurement spatiae th f so l patterns of radioactive fallout137 Cesium can be used to measure soil erosion and sediment deposition on the landscape. The 137Cs technique is the only technique that can be used to make actual measurement f soio s l losredepositiod an s n quickl efficientlyd yan understandiny B . e gth backgroun usinr dfo !37e gth C s techniqu studo et y erosio sedimend nan t depositioe th n no landscape, scientists can obtain unique information about the landscape that can help them plan techniques to conserve the quality of the landscape. Research should continue on the development of the technique so that it can be used more extensively to understand the changing landscape.

Jul6 1 y n 194O 5t 12:3a 0 Greenwich Civil Tune, nuclear weapons tests were begun that have released 137 othed Csan r radioactive nuclides intenvironmente oth . 0 5 Ove e th r years since this first test, much research has been done to understand the movement and fate e environmentf 137o th Cn i s . Man f theso y e studie e criticaar s r understandinfo l e gth application of 137Cs to the study of soil erosion and the subsequent redeposition of the eroded

particle landscapee th n o s . This bibliography presents significant background publications thausefue ar t studieo t l f erosioso sedimend nan t deposition bibliographusine CTh gs. 137 y also includes citations of reported studies of the use of 137Cs to measure either erosion or sediment deposition. Whil bibliographe eth extensives yi , ther certainle ear y publications that we have misse-.!. However, we feel that this bibliography does demonstrate the widespread use and acceptance Of 137Cs for measuring erosion and sediment deposition. We hope it will also be useful to those using or preparing to use 137Cs and will help promote the use of 137Cs in erosion and sediment deposition research and measurements.

* Document last update Januarn do y 6,1995

125 2 . BIBLIOGRAPHY

Aarkog Dal'gaardt- G , ,A. Hallstadius. ,L . Hansen,H . Holm E d .an , 1983. Radiocesium from Sellafield effluent n Greenlani s d water. Nat. 304:49-51. Aarkog, A., G. Dal'gaardt, E.N. Karavaeva, N.V. Kulikov, K. Mittenar, I.V. Milchanov, S.P. Nil'sen, V.N. Pozolotina, G.G. Polikarpov. 1992. Long-lived radionuclide concentration in the soitreed lan nuclean si r acciden tsouthere areth n ai n Urals. Ekologiya 4:50-55. (Russian) Abril, J.M. and M. Garcia-Leon. 1992. Modelos mathemäticos en radiogeocronologia. Anales de Flsica A 87:82-91. (Spanish) Abril, J.M. and M. Garcia-Léon. 1994. The integrated atmospheric flux effect in a radiogeochronological model. J. Environ. Radioact. 24:65-79. Abril, J.M. , M. Garcia-Léon., R. Gare la-Ténor io, C.I. Sanchez, "and F. El-Daoushy. 1992. Dating of marine sediments by an incomplete mixing model Environ. .J . Radioact. 15:135-151. Ackermann Bergmann. H , Schlieichert. U , F. d ,an . 1983. Monitorinf go heavy metals in coastal and estuarine sediments - A question of grain-size: <20 /jm versus <60 pm. Environ. Tech. Lett. 4:317-328. Agre, A.L. and V.I. Korogodin. 1960. The distribution of radioactive contamination in a stagnant reservoir. Medical Radiology 5:161-175. Aharoni, C. , N.S. Pasricha, and D.L. Sparks. 1992. Adsorption and desorption kinetics of cesium in an organic matter-rich soil saturated with different cations. Soil Sei. 156:233-239. Alberts, J.J d R.N.an . Muller. 1979 e distributio.Th f o n ^Pu, and 157Cs in various particle size classes of Lake Michigan sediments Environ. .J . Qual. 8:20-22. Alberts, J. J. , L.J. Tilly, and T.J. Virgerstad. 1979. Seasonal cyclin cesium-13f o g reservoira n 7i . Sei. 203:649-651. Alberts, J.J M.Ad .an . Wahlgren. 1984. Concentratio ^'-^Puf no , 137Cs, and wSr in the waters of the Laurent ian Great Lakes. Comparison of 1973 and 1976 values. Environ. Sei. Tech. 15:94-98. Alberts, J.J., M.A. Wahlgren, K.A. Orlandini C.Ad an ,. Durbahn. 1989e distributioTh . 2Wf -o n2* )Pu, ^Pu, ^'A 137d mCan s among chemically-defined components of sediments, settling particles planktot andne Lakf no e Michigan Environ. .J . Radioact. 9:89- 103. Aleksan'yan, O.M. 1978 vertica. e studA th f yo l distributio wSrf no , and '37 Cbotton si mAzovf o sediment a , se USSRa f so . Ekologiya 5:95-97. (Russian)

Aleksan'yan, O.M. and Y.Y Katsnel'son. 1979. Radioactive pollution of bottom sediments and its prevention. Soviet J. Ecol . 10:243-245. Alexander, C.R., R.G. Smith, F.D. Calder, S.J. Schropp, and H.L. Windom. 1993. The historical record of metal enrichment in two Florida estuaries. Estuar. 16:627-637. Alhonen . P 1979, e sedimentarTh . ye culturath recor f o dl eutrophication and pollution of lakes in Finland. Arch. Hydrobiologia 86:13-26.

126 Aliyev, O.A., M.A. Abdullayev, and A.T. Tagiyev. 1977. Distribution of Sr90 and Cs"7 in plowed soils of the dry (subtropical) steppe zone of the lesser Caucasus in the Azerbaijan SSR. Pochvovedeniye 7:34-35. Alldredge, A.W. and F.W. Whicker. 1972. A method for measuring soil erosio d depositioan n n with beta particle attenuation. J . -Range Manage. 25:393-398. Allison, R.J. 1992. Slope slopd san e processes: review. Prog. Phys, Geol. 15:423-427. Anderson, E.G. 1958. Radioactivity of people and milk: 1957. Sei. 128:882-886. Anderson, N.J. 1989 .whole-basiA n diatom accumulationa ratr fo e small eutrophic lakn i Northere ns it Irelan d an d palaeoecological implications Ecol. .J . 77:926-946. Anderson, N.J. 1990. Variability of diatom concentrations and accumulation rates in sediment of a small lake basin. Limnol. Oceanogr. 35:497-508. Anderson, N.J d B.V.an . Odgaard. 1994. Recent paleoliminologf o y three shallow Danish Lakes. Hydrobiologia 275/276:411-422. Anderson, R.F., S.L. Schiff R.Hd an ,. Hesslein. 1987. Determining sediment accumulatio d mixinan n g rates using 2l°Pb, I37d Can s other tracers: problems due to postdepositional mobility or coring artifacts. Can. J. Fish. Aquat. Sei. 44:231-250. Andersson, I. and H. Longjo. 1988. Transfer of Cs-137 in two farm ecosystems. Swedis Agric. hJ . Res. 18:195-206. Andersson, K.G. and J. Roed. 1994. The behaviour of Chernobyl Cs-137, Cs-134 and Ru-106 in undisturbed soil - Implications for external radiation. J. Environ. Radioact. 22:183-196. Anisimov, V.S., N.I. Sanzharova, and R.M. Aleksakhin. 1992. On the form d verticaan s l distributio 137f n o soilnCi s s neae th r acciden Chernobye th t ta l nuclear power station. Eurasian Soil Sei. 24:1-10. (Translated from Pochvovedeniye 9:31-40, 1991) Anonymous. 1988. Proceeding nationae th f f so o le workshous e th n po U7Cs to measure erosion. Soil Conservation Service of New South Wales, Sydney, Australia. pp 4 ,2 Anspaugh, L.R., R.J. Catlin Goldman. M d ,an . 1988 globae Th . l impact of the Chernobyl reactor accident. Sei. 242:1513-1519. Appleby, P.G., J.A. Dearing Oldfield. F d ,an . 1985. Magnetic studies of erosio Scottisa n i n h lake catchment . Cor1 . e chronology and correlation. Limnol. Oceanogr. 30:1144-1TS3. Appleby, P.G, and F. Oldfield. 1979. Correspondence. Environ. Sei. Tech. 13:478-490. Appleby, P.G. and F. Oldfield. 1983. The assessment of 2l°Pb data- from sites with varying sediment accumulation rates. Hydrobiologia 103:29-35.

Appbley, P.G. and F. Oldfield. 1978. The calculation of lead-210 dates assumin constanga t rat supplf eo unsupportef yo d lead- sedimente th o t 0 . 21 Catena 5:1-8. Appleby, P.G., F. Oldfield, R. Thompson, and P. Huttunen. 1978. 210Pb datin annuallf go y laminated lake sediments from Finland. Nat. 280:53-55.

Appleby, P.G. Richardson. N , P.Jd ,an . Nolan. 1991. ^'Am datinf o g lake sediment. Hydrobiologia 214:35-42.

127 Appleby, P.G., N. Richardson, P.J. Nolan, and F. Oldfield. 1990. Radiometrie dating of the United Kingdom SWAP sites. Phil. Trans. R. Soc. London B 327:233-238. Appleby, P.G J.Td .an . Smith 1993 transpore .Th radionuclidef to n si lake-catchment systems, pp. 264-275. Im Hydrological considerations in relation to nuclear power plants, Proceeding of an International Workshop, UNESCO, Paris. Armentano, T.V. and G.M. Woodwell. 1975. Sedimentation rates in a Long Island marsh determined by 210Pb dating. Linmol. Oceanogr. 20:452-455. Armstrong, N.E. and E.F. Gloya. 1969. Mathematical models for the dispersion of radionuclides in aquatic systems, pp. 329-335. In: D.J. Nelso d F.Can n . Evans (eds.), Sympositun o n radioecology, USAEC Doc. CONF-670503 AtomiS ,U c Energy Agency, Washington. ,DC Ashley, G.M. 1977. Sedimentolog tidaa f yo l river, Pitt River, B.C. Ph.D. Thesis, Univ. of British Columbia, Vancouver, BC.

Ashley, G.M. and L.E. Moritz. 1979, Determination of lacustrine sedimentation rate radioactivy sb e fallout (l37Cs), Pitt Lake, British Columbia. Can. J. Earth Sei. 16:965-970. Ashwood, T.L. and C.R. Olsen. 1988. Pearl Harbor bombing attack: a contamination legacy revealed in the sedimentary record. Marine Pollut. Bull. 19:68-71. Assinder, D.J. Kelly. ,M S.Rd ,an . Aston. 1985. Tidal variationn si dissolved and particulate phase radionuclide activities in the Esk estuary and their distribution coefficients and particulate activity fraction. J. Environ. Radioact. 2:1-22. Assimakopoulos, P.A., K.G. loannides, D.T. Karamanis, A.A. Pakou, K.C. Stamoulis, A.S. Mantzios . NikolaouE d an , . 1993. Radiocaesium transfe o sheep't r s a resulmil s a f ksoio t l ingestion. Sei. Total Environ. 136:13-24. Assimakopoulos, P.A., K.G. .loannides, D.T. Karamanis, A.A. Pakou, K.C. Stamoulis, A, Vayonakis, and E. Veitsos. 1993. Time dependenc transfee th f eo r facto Cs-13f ro 7 from surface soil to plants. Sei. Total Environ. 138:309-315. Aston, S.R. and E.K. Duursma. 1973. Concentration effects of I37Cs, "Zn, *°Cod 106an Ru, sorptio y marinb n e sediments with geochemical implications. Neth. J. Sea Res. 6:225-240. Aston, S.R d J.Ean . . Rae. 1982 e depositioTh . f Windscalo n e radiocaesiu e Wyrth en e measuremeni mEstuarth d an y f o t sedimentation rates. Marine Environ. Res. 7:83-90. Aston, S.R. and D.A. Stanners. 1979. The determination of estuarine sedimentation rate y b ^Cs/'^Cs d othean s r artificial radionuclide profiles. Estuar. Coast. Marine Sei. 9:529-541. Aston, S.R. and D.A. Stanners. 1982. Gamma emitting fission products in surface sediment Ravenglase th f so s estuary. Mar. Pollut. Bull. 13:135-138. Aston, S.R d D.Aan . . Stanners. 1982. Local variabilite th n i y distributio f Windscalo n e fission product n estuarini s e sediments. Estuar. Coast. Shelf Sei. 14:167-174. Auerbach, S.I., J.S. Olson d H.Dan , . Waller. 1964. Landscape investigations using cesium-137. Nat. 201:761-764. Autenreith, R.L., J.S. Bonnet. SchriebelL d an , . 1991. Aquatic sediment. Res Wate. .J r 63:709-725.

128 Authur, W.J. 1982. Radionuclide concentration in vegetation at a radioactive waste-disposal are southern ai n Idaho Environ. .J . Qual. 11:394-399. Avnimelech, Y., J.R. McHenry, and J.D. Ross. 1984. Decomposition of organic matter in lake sediment. Environ. Sei. Tech. 18:5-11. Bachhuber BunzlSchiramack. . K W d , ,,an H. . 1986. Spatial variability of distribution coefficient 137f o sCs , eZn, ""Sr, "Co, 109Cd, u'Ce, 103Ru, 95mTc, and I3II in cultivated soil. Nucl. Tech. 72:359-371. Bachhuber BunzlSchimraack. . K W d , ,an H. . 1987. Spatial variability of fallout 137Cs in the soil of a cultivated field. Environ. Monit. Assessment 8:93-101. Bachhuber . BunzlK , . SchimmacW ,H. . , GansI d .an k 1982e Th .

migrationC sof and *°Sr in multilayered soils: results from batch, column falloud IJ7 ,an t investigations. Nucl. Tech. 59:291- 301. Baeza. DelrioM , . Paniagua. MiroJ ,A. C , d an , . 1993. Surfacd an e depth fallout distributio Cs-13f o n d Sr-9 an 7n soil i 0 f o s Caceres (Spain) - Dose commitments due to external irradiation Radiât. .J . Nucl. Lett. 175:297-316. Baltakmens, T. and L.P. Gregory. 1977. Profile of "Sr and "7Cs concentration selecten si Zealanw dNe d soil theid san r bearing on milk contamination levels. N.Z. J. Sei. 20:425-431. Barber, D.A. 1964. Influence of soil organic matter on the entry of caesium-137 into plants. Nat. 204:1326-1327. Barbeau, C, , R. Bougie, and J.E. Coté. 1981. Variations spatiales et temporelles du césium—137 et du carbone dans des sédiments du fjord du Saguenay. Can. J. Earth Sei. 18:1004-1011. (French) Barnaby, F. 1986. Chernobyl: thé conséquences in Europe. Ambio 15:332-334. Basher, L.R K.Md ,an . Matthews. 1993. Relationship between 137Cn s,i some undisturbed New Zealand soils and rainfall. Aust. J. Soil Res. 31:655-663. Battarbee, R.W. 1978. Observations on the recent history of Lough drainags it Neag d an he basin. Phil. Trans Soc. .R . LondonB 281:303-345. Battarbee, R.W. 1984. Diatom analysi acidificatiod san f lakesno . Phil. Trans. R. Soc. London B 305:451-477. Battarbee, R.W. 1986 eutrophicatioe .Th Lougf no h Erne inferred from change diaton si m assemblage 2l f °PbI37so d Cs-date-an d sediment cores. Proc. R. Irish Acad. 86B:141-168. Battarbee, Digerfeldt. R.WG d .an . 1976. Palaeoecological studief so recent developments of Lake Växjösjön. I. Introduction and chronology. Arch. Hydrobiologia. 77:330-326. Battarbee, R.W. Digerfeldt. ,G Appleby. ,P Oldfield. F d ,an . 1980. Palaeoecological studie f receno s t development f Lako s e Växjösjön. III. Reassessmen recenf to t chronolog basie th sn yo of modified 210Pb dates. Arch. Hydrobiologia. 89:440-446. Battiston, G.A., S. Degetto, R. Gerbasi, and G. Sbrignadello. 1989. Determination of sediment composition and chronology as a tool for environmental impact investigations. Marine Chem. 26:91-100.

129 Battiston, G.A. . ,DegettoS Gerbasi. R , . Sbrignadello,G . L d an , Tositti e stud d 210f th "o f P 7an .bo C n y e i s 1988us e Th . sediment pollution in a lagoon of Venice. Sei. Total Environ. 77:15-23. Baxter, M.S., R.W. Crawford, D.S. Swan J.Gd ,an . Farmer. 1981.210 Pb datin a Loc f ho g Lomand sediment cor y conventionab e d an l particle track methods and some geochemical observations. Earth Planet. Sei. Lett. 53:434-444.

Baxter, M.S., J.G. Farmer, I.G. McKinley, D.S. Jacks. SwanW d ,an . 1981. Evidence of the unsuitability of gravity coring for collecting sediment in pollution and sedimentation rate studies. Environ. Sei. Tech. 15:843-846.

-Baxter, M.S., I.G. McKinley, A.B. MacKenzie, and W. Jack. 1979. Windscale radiocaesiu Clyde areaa th eSe n i m. Marine Pollut. Bull. 10:116-120. . PanicucciM Bazzoffi d an . .P , 1983. Erosion i versantsu e e i congequente sedimentazion piccoln i e i serbatoi artificiali.' Znst. Sperimentale Studio e Difesa Suolo, Firenze 14:127-178. (Italian) Beasley, T.M., R. Carpenter, and C.D. Jennings. 1982. Plutonium, 137d C^'Aan s m ratios, inventories d verticaan , l profilen i s Washingto Oregod an n n continental shelf sediments. Geochim. Cosmochim. Acta 46:1931-1946. Beasley, T.M C.Dd .an . Jennings. 1984. Inventorie 2Wf -so 2* 1Pu, ^'Am, 137Cs, and "Co in Columbia River sediments from Hanford to the Columbia River Estuary. Environ. Sei. Tech. 18:207-212. Beck, H.L. 1966. Environmental gamma radiation from deposited fission products 1960-1964. Health Phys. 12:313-322. Begrgström Nordlinder. S d an . ,U . 1989. Compariso predictef no d dan measured Cs-137 in a lake ecosystem, pp. 283-288. In: W. Feldt e radioecologTh (ed ) . f o natura yd artificiaan l l radionuclides, Proceedings of the 15th. Regional Congress of the International Radiation Protection Association of Radioecology of Natural and Artificial Radionuclides, Visby, Sweden. Bell, G.L. and B.J. Eadie. 1983. Variation in the distribution of suspended particles during an upwelling event in Lake Michigan in 1980. J. Great Lakes Res. 9:559-567. BlasiBelli. M , Capra. ,E M. Drigo. ,A Menegon. ,S Piasentier. ,E , an. SansonedU . 1993. Ingested sourcsoia s l a Cs-13 f eo o 7t ruminants. Sei. Total Environ. 136:243-249. . SansoneBelliU , M. ,. Piasentier ,E . Capra,E . Drigo. S ,A d an , Menegon. 1993. Cs-137 transfer coefficients from fodder to .cow milk Environ. .J . Radioact. 21:1-8. Belperio, A.P., B.W. Smith, H.A. Polach, C.A. Nittrouer, D.J. DeMaster, J.R. Prescott, J.R. Hails, and V.A. Gostin. 1984. Chronological studieQuaternare th f so y marine sedimentf so northern Spencer Gulf, South Australia. Marine Geol. 61:265-296. Benes, P., M. Cernik, and P. Lam Ramos. 1992b. Factors affecting interactio radiocesiuf no m with freshwater solids Contac. .II t time, concentratio solif no temperatured dan Radioanalyt. .J . Nucl, Che» Articles 159:201-218. CernikBenes. M Slâvik. O , d ,P. , an . 1994. Modellin migratiof go f no Cs accidently released int a smalo l river . EnvironJ . .

Radioact137 . 22:279-293.

130 Benninger, L.K. and M.M. Brinson. 1988. Chronometrie radionuclides in sediments of Cedar Island Salt Marsh, North Carolina. EOS Trans. 69:379. Benninger, L.K J.Td an . . Hells. 1993. Source f sedimenso e th o t t Neuse River estuary, North Carolina. Marine Chemistry 43:137- 156. Benson, D.W. 1960. Revie soif wo l chemistry researc Hanfordt ha - .HW 67201, Batelle Northwest Laboratory, Richland, WA. Merlini. BergM , , A. Ravera . ,Tonolli. O V d ,an . 1961. Accumulation of fission products from fall-ou n Laki t e Biota (Lago Maggiore). Final Report, Contract No. 59, Rept. CNI-109, International Atomic Energy Agency, Vienna, Austria. Bergeijk van, K.E., H. Noordijk, J. Lembrechts, and M.J. Frissel. 1992. Influenc soi, pH l f typeo soid an el organic matten o r soil-to-plant transfer of radiocesium and radiostrontium an analyze a nonparametri y b d c method . EnvironJ . . Radioact. 15:265-276. Berger, G.W. Eisma. ,D A.Jd Bennekomn an , va . . 1987. 210Pb derived sedimentation rate in the Vlieter, a recently filled-in tidal channel in the Wâdden Sea. Neth. J. Sea Res. 21:287-294. Bergersen, E.P. 1987. Aldrin, dieldrin, and mercury profiles in recent lake sedimen Rocke th yt ta Mountain Arsenal, Colorado. Arch. Environ. Contam. Toxicol. 16:61-67. Bernard, C. and M.R. Laverdière. 1990. Variabilité spatiale de l'activitie en césium-137 et ses repercussions sur l'estimation de l'érosion hydrique. Pédologie 40:299-310. (French) Bernard, C. and M.R. Laverdière. 1992. Spatial redistribution of cesium-137 and soil erosion on Orleans Island, Quebec. Can. J. Soil Sei. 72:543-554. Bernard M.R, .,C. Laverdière A.Rd ., an Pesant. 1992. Variabilite éd la relation érosio r entr pa pertes l ele n so césiue sd e d t me hydrique. Geoderma 52:265-277. (French) d M.FBertinean .. K . MendeckK , . 1978. Industrializatiow Ne f o n Haven, Conn., as recorded in reservoir sediments. Environ. Sei. Tech. 12:201-207.

Bettoli, M.G., L. Cantelli, M. Cecchini, L. Tositti, O. Tubertini, and S. Valcher. 1994. Vertical distribution of Cs-137 in the lacustrine area preliminard san y result Be-f so 7 activitn i y snow sample t Terra-Nova s y (Antarctica)Ba a . Internat. J . Environ. Analyt. Chem. 55:253-260. Bickford, M.E. and W.R. Van Schmus. 1979. Geochronology and radiogenic isotope research. Rev, Geopbys. Space Phys. 17:824-839.

Bilo, M., W. Steffens, F. Fuhr, and K.H. Pfeffer. 1993. Uptake of Cs-134/Cs-13 soin 7 i cereal y lb functioa s sa severaf no l soil parameters of 3 soil types in upper Swabia and north Rhine-Westphalia (FRG) Environ. .J . Radioact. 19:25-39.

Binford, M.W. 1984.—Dating lake sediment cores wit: PbIn h. Proceedings workshop on paleolimnological studies 210 of the histor effectd yan acidif so c precipitation 23-24y ,Ma , 1984, Rockland. ,ME Bird, G.A. and W.G. Evenden. 1994. Effect of sediment type, temperature and colloids on the transfer of radionuclides from wate sedimento rt Environ. .J . Radioact. 22:219-242.

131 Bishop, P., B. Campbell, and C. McFadden. 1991. Absence of caesium- 7 fro13 m recent sediment eastern si n Australi Indicationa- s of catchment processes. Catena 18:61-69. Blakar, I.A., D. Hongve, and O. Njastad. 1992. Chernobyl cesium in the sediments of Lake Hoysjoen, Central Norway. J. Environ. Radioact. 17:49-58. Bloemenda . OldfieldF . ThompsonR , J. d l an , . 1979. Magnetic measurements used to assess sediment influx at Llyn "Goddionduon. Nat. 280:50-53. Bloesch, J. and M. Strum. 1986. Settling flux and sinking velocities of particle phosphorus (PP) and particulate organic carbon (POC) in Lake Zug, Switzerland, pp. 481-490. In: P.G. Sly (ed.), Sediment and water interactions, Springer-Verlag, New York. Bodbacka . 1986,L . Sediment accumulatio Lakn i n e Lilla Ullfjärden and Stora Ullfjärden, Sweden. Hydrobiologia 143:337-342. Bonazzola ,. Ropolo R G.G d an .. 1986. Environmental radioactivity measurements after the Chernobyl accident. II Nuovo Saggiatore 3:135-143. (Italian) Bonazzola, G.G. Ropolo. R ,Facchinelli. A d ,an . 1993. Profiled san downward migration of 134Cs and 10

Bonnett, P.J.P P.Gd .an . Appleby. 1994. Rate removaf so sedimenf lo t associated radiocaesium from the Plynlimon Experimental Catchment, Powys, UK. Environ. Pollut. 83:327-334. Bonnett, P.J.P., P.G. Appleby Oldfield. F d ,an . 1988. Radionuclides in coasta estuarind lan e sediments from Wirra Lancashired lan . Sei. Total Environ. 70:215-236. Bonnett, P.J.P R.Sd .an . Cambry. 1991 recore .Th depositiof do f no radionuclides in the sediments of Ponsonby Tarn, Cumbria. Hydrobiologia 214:63-70. Bonnett, P.J.P., G.J.L. Leeks, and R.S. Cambry. 1989. Transport processes for Chernobyl-labelled sediments: preliminary evidence from upland mid-Wales. Land Degradatiod an n Rehabilitation 1:39-59. Bonny, A.P. 1976. Recruitment of pollen to the seston and sediment of some Lake District lakes. J. Ecol. 64:859-887. Bonny, A.P. 1978. The effect of pollen recruitment processes on pollen distribution over sediment surface of a small lake in Cumbria. J. Ecol. 66:385-416.

132 Bopp, R.F., H.J. Simpson, S.N. Chillrud, arid D.W. Robinson. 1993. Sediment-derived chronologies of persistent contaminants in Jamaica Bay, New York. Estuar. 16:608-616.

Bopp, R.F., H.J- Simpson, C.R . KostykN Olsen d an ., 1981. Polychlorinated biphenyl n sedimenti s e tidath f lo s Hudson River, New York. Environ. Sei. Tech. 15:210-216.

Borzilov, V.A., A.V. Konoplev A.Ad an , . Bulgakov. 1993. Application of the chernobyl experience in developing methodology for assessing and predicting the consequences of radioactive contamination of the hydrosphere, pp. 246-263. In: Hydrological considerations in relation to nuclear power plants, Proceeding of an International Workshop, UNESCO, Paris. Boudreau, B.P. 1986a. Mathematics of tracer mixing in sediments: I. spatially-dependent, diffusive mixing. J Sei. Am .. 286:161- 198. Boudreau, B.P. 1986b. Mathematics of tracer mixing in sediments: II. nonlocal mixing and biological conveyor-belt phenomena. Am. J. Sei. 286:199-238. Bowen, V.T., V.E. Noshkin, and H.L. Volchok. 1970. Can land run-off be a major vector of fallout to the ocean. HASL-217, pp. 1-119 to 1-125. Health and Safety Laboratory, New York.

Brakensiek, D.L., H.B. Osborn, and W.J. Rawls. 1979. Field manual for researc n i agriculturah l hydrology. USDA Agriculture Handboo . 224 No DepartmenkS U , f Agricultureo t , Washington, DC. Bray D.I. and H.X. Xie. 1993. A regression method for estimating suspended sediment yield from ungauged watershe n Atlantii d c Canada. Can. J. Civ. Engr. 20:82-87.

Brewster, G.R. and V. Pillay. 1991. Using Cs-137 to assess soil erosion in the Cobeguid Bay area of Nova Scotia. Can. J. Soil Sei. 71:261-262.

Brisbin, I.L. Jr., R.J. Beyers, R.W. Dapson, R.A. Geiger, J.B. Gentry, J.W. Gibbons, M.H. Smith, and S.K. Woods. 1974. Pattern f radiocesiuo s e sedimentth n mi a strea f o s m channel contaminated by production reactor effluent. Health Phys. 27:19-27.

. AnderssonE Broberg d an . A , . 1991. Distributio circulatiod nan • nof Cs-13 n laki 7 e ecosystems . 151-175 . Moberpp ,L ; In g. (ed.), The Chernobyl fallout in Sweden, Swedish Radiation Protection Institute, Stockholm, Sweden. Broom, M.J., P.D. Grimwood, and E.G. Bellinger. 1973. Caesium-137: its accumulation in littoral community. Marine Pollut. Bull. 6:24-26. Brown 1987a. ,L . IOBe: recent application eartn i s h science. Phil. Trans Soc. .R . Londo n323:75-86A . Brown 1987b. ,L . '°Btracea es a erosiof ro sedimend nan t transport. Chem. Geol. 65:189-196. Brown, L., M.J. Pavich, R.E. Hickman, J. Klein, and R. Middleton. 1988. Erosio eastere th f no n United States observed with 10Be. Earth Surf. Processes Landforms 13:441-457. Brown, L.R. and E.C. Wolf. 1984. Soil erosion: quiet crisis in the world economy, Worldwatc . Worlpp hd1 5 PapeWatch , 60 r , Washington, DC.

133 Brown, R.B. 1980. Agricultural erosio sedimend Westere nan th n i tn Willamette Valle s indicatea ye redistributioth y b d f o n cesium-137. Ph.D. Thesis, Oregon State Univ., Corvallis. ,OR (DAI no. 41:1191-b) Brown, R.B., N.H. Cutshall, and G.F. Kling. 1981. Agricultural erosion indicate y 137b dCs redistribution . levelI :d an s distribution of 137Cs activity in soils. Soil Sei. Soc. Am. J. 45:1184-1190. Brown, R.B., G.F. Kling d N.Han , . Cutshall. 1981. Agricultural erosion indicate l37y b Cds redistribution . estimateII : f o s erosion rates. Soil Sei. 45:1191-1197. SocJ . .Am . Brown, R.B G.Fd .an . Kling, 1980. Erosio sedimend nan indicates ta d by redistribution of cesium-137, Chapter 7. Spec. Report Oregon Agricultural Experiment Station, Nov. 1980 (602) pp. 90-108. Brugam, R.D. 1978. Pollen indicator land-usf so e chang Southern ei n Connecticut. Quat. Res. 9:349-362. . GeorgiiS . BrunnEskensU , d H. ,an ., 1993, Cesium-13d an 7 cesium-134 in roe deer from North and Middle Hesse (Germany) subsequen e reactoth o t rt acciden n Chernobyli t . Bull. Environ. Contain. Toxicology 51:633-639.

Brunskill, G.J., S.D. Ludlam, and T.H. Peng. 1984. Fayetteville Green Lake w YorkNe , , U.S.A. VIII. Mass balanc l37f n o Cei s water, varve non-varved an d d sediments. Chem. Geol. 44:101- 117. Brunskill, G.J. Povoledo. ,p , B.W. Graham M.Pd ,an . Stainton. 1971.

Annual supply *oof, **U,Th*RaPb,°P,o anThd to

230 22 210 2l n2 lak9 (Experimentae23 l Lakea s Area, northwestern Ontario) from terrestria atmospherid lan c sources. Can Fish. .J . Aquat. Sei. 44:215-230. Brush, G.S. 1984. Patterns of recent sediment accumulation in Chesapeake Bay (Virginia-Maryland, U.S.A.) tributaries. Chem. Geol. 44:227-242. Brush, G.S., E.A. Martin, R.S. DeFries, and C.A. Rice. 1982. Compariso 2lpollef d °Pno ban n method determininr sfo g ratef so estuarine sediment accumulation. Quat. Res. 18:196-217. Brydsten, L. and M. Jasson. 1989. Studies of estuarine sediment dynamics using l37Cs froTjernobye mth l acciden tracera s ta . Estuar. Coast. Shelf Sei. 28:249-259. Bubenzer, G.D. 1986. Quantifying erosion losses using cesium-13.7. 198e Papeth 6f Summero rSoc. MeetingAm e . th Agricf so . Engr. (ASAE Microfiche 86-2042).

Buesseler, K.O., H.D. Livingston . HonjoS , , B.J. Hay, S.J. Manganini, E. Degens, V. Ittekkol, E. Izdar, and T. Konuk. 1987. Chernobyl radionuclides in a Black Sea sediment trap. Nat. 329:825-828. Buesseler, K.O d E.Ran . . Sholkovitz. 1987 e geochemistrTh . f o y fallout plutonium in the North Atlantic: I. a pore water study in shelf, slope and deep-sea sediments. Geochim. Cosmochim. Acta 51:2605-2622. Bulygin, S.Y., G.A. Mozheiko, and D.O. Timchenko. 1992. Rate of chernozem erosion in the Donetsk steppe. Prochvovedeiye 8:121- 128. (Russian)

134 BunzlForster. H , ,K. Kracke . ,W Schimmack. W d ,an . 1994. Residence time fallouf so t Pu-239+240, Pu-238, Am-24 Cs-13d e 1an th n 7i upper horizons of an undisturbed grassland soil. J. Environ. Radioact. 22:11-27. Bunzl, K. and W. Kracke. 1984. Distribution of 2IOPb, 2l°Po, stable lead and 137Cs in soil, plants and moorland sheep of a heath. Sei. Total Environ. 39:143-159. Bunzl, K. and W. Kracke. 1988. Cumulative deposition of '37Cs, ^Pu, 239+2«>pu and »i^ from global fallout in soils from forest, grasslan d arablan d e lann Bavarii d a (FRG) . EnvironJ . . Radioact. 8:1-14. Schimmack. W Bunzld an . ,K . 1991. Kinetic sorptiof so l37f no Cs , "Sr, 57Co, «Zn and ""cd by the organic horizons of a forest soil. Radiochim Acta 54:97-102.

Bunzl, K. , W. Schimmack, K. Kreutzer, and R. Schierl, 1989a. The migratio fallouf no t 134Cs, 10l37d *RCusan from Chernoby 137d Clan s from weapons testin a fores n i gt soil . pflanzenernahrZ . . Bodenk 152:39-44. Bunzl— K., W. Schimmack, K. Kreutzer, and R. Schierl. 1989b. Interception and retention of Chernobyl-derived l34Cs, 137Cs and spruca lo6 n Ri u e stand. Sei. Total Environ. 78:77-87. Bunzl, K. and W. Schultz. 1985. Distribution coefficients of I37Cs and "Sr by mixtures of clay and humic material. J. Radioanal. Nucl. Chem. Art. 90:23-37. Buravlev, Y.P., M.N. Lebedinskiy, S.K. Drich, and V.K. Churaak. 1992. Migration of Cs-137 and Ce-144 in soils of the evacuated zone around the Chernobyl Nuclear Power Plant. Soviet Soil Sei. 23:121-125. Burch, G.J., C.J. Barnes, I.D. Moore, R.D. Barling, D.H. Mackensie, and J.M. Olley. 1988. Detection and prediction -of sediment sources in catchments: use of Be-7 and Cs-137, pp. 146-151. Im Proceedings, hydrology and water resources symposium, Australian Inst. Eng., Canberra, Australia. Busacca, A.J., C.A. Cook, and D.J. Mulla. 1993. Comparing landscape- scale estimatio soif no l erosio e Palousth n ni e using Cs-137 and RUSLE. J. Soil Water Conserv. 48:361-367. Bush, B., L.A. Shane, M. Wahlen, and M.P. Brown. 1987. Sedimentation S congener PC e uppe 4 oth 7 f r n i sHudso n River. Chemosphere 16:733-744. Cahill, R.A d J.Dan . . Steele. 1986. a trace' 37s C sa f recen o r t sedimentary processes in Lake Michigan. Hydrobiologia 143:29-35. Cahill, R.A. and M.T. Unger. 1993. Evaluation of the extent of contaminated sediment Wese th t n GranBrance si th df h o Calume t River, Indiana-Illinois, USA. Water Sei. Tech. 28:53-58. Caitcheon, G. 1990. Sedimentation in Lake Albert - the history of sediment sources and catchment sediment yields. Aust. J. Soil Water Conserv. 3:42-46. Caitcheon, G.G. 1993a. Applying environmental magnetism to sediment tracing. IAHS Publ. Ho.215:285-292. Caitcheon, G.G. 1993b. Sediment source tracing using environmental magnetism w approacne a : h with examples from Australia. Hydrol. Processes 7:349-358.

135 Calcagno, T.H d G.Man . . Ashley. 1984. Sediment processen a n i s impoundment, Union Lake Jerseyw ,Ne . Environ. Geol. Water Sei. 6:237-246. Callender, E. and J.A. Robbins. 1993. Transport and accumulation of radionuclide d stablan s e element a Missour n i s i River reservoir. Water Resour. Res. 29:1787-1804.

Cambray, R.S., P.A. Cawse, J.A. Garland, J.A.B. Gibson Johnson. ,P , G.N.J. Lewis, D. Newton, L. Salmon, and B.O. Wade. 1987. Observations on radioactivity from the Chernobyl accident. Nucl. Energy 26:77-101. Cambray, R.S d J.Dan . . Eakins. 1980. Studie f environmentao s l radioactivity in Cumbria, Part 1. Concentrations of plutonium and 137Cs in environmental samples from West Cumbria and a possible maritime effect. AERE-R-9807. U.K. Atomic Energy Authority Report, Harwell. ,UK

Cambray, R.S d J.D.an . Eakins. 1982 , ^'Ar 137d n soiCPu .i an san i l West Cumbri maritima d aan e effect, Nat, 300:46-48. Cambray, R.S., K. Playford, and G.N.J. Lewis. 1983. Radioactive fallout in air and rain: results to the end of 1982. AERE-R- 10859. U.K. Atomic Energy Authority Report, Harwell, UK. Cambray, R.S. . PlayfordK , G.N.Jd an , . Lewis. 1985. Radioactive rain1984f d o an fallou d :r .en ai result e AERE-Rn th ti o st - 11915. U.K. Atomic Energy Authority Report, Harwell, UK. Cambray, R.S. Playford. ,K , G.N.J. Lewis R.Cd ,an . Carpenter. 1990. Radioactiv f raind o e an d :fallour en resultai e n th i t o t s 1988. AERE-R-13575. U.K. Atomic Energy Authority Report, Harwell. ,UK Campbell, B.L. 1982. Application of environmental caesium-137 for •the determinatio f sedimentatioo n n rate n reservoiri s d an s lake d relatean s d catchment studie developinn i s g countries. AAEC Research Establishment, Lucas Heights Research Lab.B ,PM Sutherland 3322, N.S.W., Australia. Campbell, B.L. 1983. Applicatio environmentaf o n l caesium-13r fo 7 the determination of sedimentation rates in reservoirs and lake d relatean s d catchment studie developinn si g countries. Radioisotope n Sedimeni s t Studies, Tech. Doc. 298:7-30, International Atomic Energy Agency, Vienna, Austria. Campbell, B.L., P.L. Airey G.Ed an , . Calf. isotopif 1987o e Us . c techniques in hydrological and erosion-sedimentation studies in tropica temperatd lan e Asian-Pacifi e zoneth f so c region, pp. 751-766. Im V. Gardiner (ed.), International geomorphology, Part 1. Wiley, London. Campbell, B.L., G.L. Elliott, and R.J. Loughran. 1980a. Nuclear fallout aidhydrologiste sth . Environ. Newsletter 5:2-3. Campbell, B.L., G.L. Elliott R.Jd an ,. Loughran. 1980b. Sediment dynamic smala n si l Hunter Valley catchment ,1-17. Volpp , ..6 In: Hunter environment, Univ. Newcastle, N.S.W., Australia. Campbell, B.L., G.L. Elliott R.Jd an , . Loughran. 1985. Nuclear measurino t d fallouai n a g s soita l erosion Soi. .J l Conserv. New South Wales 42:86-89. Campbell, B.L., G.L. Elliott R.Jd ,an . Loughran. 1986. Measurement

of soil erosion from fallouCs.t Search 17:148-149. 137 Campbell, B.L., R.J. Loughran G.Ld ,an . Elliott. 1982. Caesium-137 as an indicator of geomorphic processes in a drainage system. Aust. Geographical Studies 20:49-64.

136 Campbell, B.L., R.J. Loughran, and G,L. Elliott. 1988. A method for determining sediment budgets using caesium-137. IAHS Publ. No. 174:171-179. Campbell, B.L., R.J. Loughran, G.L. Elliott D.Jd ,an . Shelly. 1986. Mapping drainage basin sediment sources using caesium-137. IAHS Publ 159:437-446. .No . Campbell, . RossB.L.M d ."an 1980. Determinatio f sedimentatioo n n rat Stephenn ei s Creek reservoir using environmental caesium- 137. Papers of the Newcastle (16th) Conf., Inst. Aust. Geographers, pp. 43-51. Cao, Y.Z., D.R. Coote, N.C. NolinWang. C d ., an 1993. Using I37Co st investigate net soil erosion at two soil benchmark sites in Quebec. Can Soi. .J l Sei. 73:515-526. Cao, Y.Z., D.R. Coote, H.W. Rees . Wang C ,T.Ld an , . Chow. 1994. Effects "of intensive potato production on soil quality and yield at a benchmark site in New Brunswick. Soil Tillage Res. 29:23-34. ' Capra, D-, U. Facchini, V. Gianelle, G. Ravasini, O. Ravena, A. Pizzala . BacciP d .an , 1987 e ChernobyTh . l accidente th : radioactive contamination in the area of Lake Como and in other Northern Italy sites. Nuovo Ciaento 10:285-313. . LarsenG d an . , 1984Bo Carlsen . P . , Radionuclide-humiL. , c acid interactions studie y dialysisb d . 167-178pp , : G.GJn . . Barney, J.D. Navratil, and W.W. Schultz (eds.), Geochemical behavior of disposed radioactive waste, American Chemical Soc., Seattle, Wa. Carlsson, S. 1976. Cesium-137 in a dysoligotrophic lake, a radioecological field study. LUNDO-MERI-NFRA 76-1005. pp 0 ,18 Radiation Physic Department, Univ. Lund, Lund, Sweden. Carlsson . 1978,S movemene th mode.A r d losa fo ll37an tf so n C i s small watershed. Health Phys. 34:33-37. Carpenter T.M, ,R. . Beasley Zahnle. ,D B.L.Kd ,an . Somayajulu. 1987. Cycling of fallout (Pu, ^'Am, 137Cs) and natural (U, Th, 2IOPb) radionuclide n Washingtoi s n continental slope sediments. Geochim. Cosmochim. Acta 51:1897-1921. d M.W.Lan . .P Carr . A Blackley, . 1986, Implicationf o s sedimentological and hydrological processes on the distribution of radionuclides: an example of a salt marsh near Ravenglass, Cumbria, Estuar. Coast. Shelf Sei. 22:529-543. Carrard . (Comp,G .198O) . Nuclear metho givn ca de early warninf go erosion. AAEC Nucl. News 7:1-2. Carringan R.Jd , an P.A .. Pickering.Jr . 1967. Radioactive materials in bottom sediments of the Clinch River. ORNL-3721, Part A and B, Oak Ridge National Laboratory, Oak Ridge, TN.

Carter, M.W d A.Aan . . Moghissi. 1977. Three decade f nucleao s r testing. Health Phys. 33:55-71. Cawse, P. 1983. The accumulation of l37Cs and z^+^pu in soils of Great Britain transfed ,an vegetationo rt 47-61. ,pp m .P.JI . Coughtrey (ed.), Ecological aspects of radionuclide release. Blackwell, Oxford. Cawse, P.A. and A.D. Horrill. 1986. A survey of caesium-137 and plutoniu n Britisi m h soil n 1977i s . AERE R-10155. United Kingdom Atomic Energy Authority Report, Harwell. ,UK

137 Cerling, T.E., S.J. Morrison R.Wd .,an Sobocinski. 1990. Sediment- water interaction in a small stream: adsorption of 137Cs by bed load sediments. Water Resour. Res. 26:1165-1176. Cerling, T.E. and R.R. Turner. 1982. Formation of freshwater Fe-Mn coating n graveo s d behavioan l f ""Coo r ,a d 137"Srn Can i s, small watershed. Geochim. Cosmochim. Acta 46:1333-1343. . B SchreiberCerrai . C , Triulzi E. d , an , . 1967. Vertical distributio f Sro n90 , Ce144, Pm d Eu 147coastan an lj,i 5 l marine sediments. Energia Nucleare 14:586-592. Triulzi. C d an Cerrai . B 1969, ,.E. Vertical distributio Csf no 137 , Sb'25, and Co60 in coastal marine sediments. Energia Nucleare 16:36-40. Chakrapani . SubramanianV , d G.Jan . . 1993. Rate f erosioo s d an n sedimentation in the Mahanadi River Basin. India J. Hydrol. 149:39-48. Chamard R.H, ,P. . Velasco Belli. ,M Disilvestro. ,G Ingrao. ,G d ,an U. Sansone. 1993 Caesium-13 strontium-9d 7an 0 distribution ni a soil profile. Sei. Total Environ. 136:251-258. Chamberlain, A.C. 1970. Interceptio d retentioan n f radioactivno e aerosols by vegetation. Atmos. Environ. 4:57-78. Chant, L.A. and R.J. Cornett. 1991. Smearing of gravity core profiles in soft sediment: note. Limnol. Oceanogr. 36:1492- 1498. Chanton, J.P., C.S. Martens d G.Wan , . Kipphut. 1983. Lead-210 sediment geochronology in a changing coastal environment. Geochim. Cosmochim. Acta 47:1791-1804. Charles, D.F., D.R. Whitehead, D.R. Engstrom, B.D. Fry, R.A. Kites, S.A. Norton, J.S. Owen, L.A. Roll, S.C. Schindler, J.P. Smol, A.J. Uutala, J.R. Whited R.Jan , . Wise. 1987. Paleolimnological evidence for recent acidification of Big Moose Lake, Adirondack Mountain N.Y. (USA). Biogeochemistry 3:267-296.

Charles, M.J d R.Aan . . Kites. 1987. Sedimen s archivea t f o s environmental pollution trends. Adv. in Chem. Series 216:365-389.

Chebotina, d V.FM.Yan . . Bochenin I37d n bottoCi an s . r m1981*S . sediments of a fresh water lake. Gidrobiol. ZH 17:82-82. (Russian) Chershire, . StrandC M.V d an .. 1991, Translocatio d planan n t availability of radiocaesium in an organic soil. Plant and Soil 134:287-296. Chelmicki, W. and J. Swiechwicz. 1992. Application of Cs-137 and soil trapping method r studyinfo s g slope processee th n i s Carpathian foothills. Pirineos 139:3-14. Chenouard Lalou. C d .an . 1969,L . Gamma-ray spectrometr tooa s lya fo rapia r d investigatio detritif no c cores . Sedimentar.J y Petrology 39:1477-1483. Cheshire, . ShandC M.V d .an . 1991. Translocatio d planan n t availabilit f radiocaesiuo y n organia n i m c soil. Pland an t Soil 134:287-296. Chittenden D.M. II 1983. Factors affecting the soluble-suspended distribution of strontium-90 and- cesium-137 in Dardanelle Reservoir, Arkansas. Environ. Sei. Tech. 17:26-31.

138 Chmura, G.L. and E.G. Kosters. 1994. Storm deposition and Cs-137 accumulation in 'fine-grained marsh sediments of the Mississippi Delta Plain. Estuar. Coastal Shelf Sei. 39:33-44. Choppin, G.R. 1988. Humics and radionuclide migration. Radiochimica Acta 44/45:23-28. Christensen, E.R. 1982. A model for radionuclides in sediment influence mixiny db compactiond gan Geophys. .J . Res. 87:566- 572. Christensen, E.R P.Kd .an . Bhunia. 1986. Modelling radiotracern si sediments: comparison with observation Lakn si e Michigad nan Huron. J. Geophys. Res. 91:8559-8571. Christensen, E.R. and N. Chien. 1981. Fluxes of arsenic, lead, zinc, and cadmium to Green Bay and Lake Michigan sediments. Environ. Sei. Tech. 15:553-558. Christensen, E.R. and R.J. Klein. 1991. Unmixing of "7Cs, Pb, Zn, and Cd records in lake sediment. Environ. Sei. Tech. 25:1627- 1637. Christensen, E.R. and C.K. Lo. 1986. Polychlorinated biphenyls in dated sediments of Milwaukee Harbour, Wisconsin, USA. Environ. Pollut. (Series B) 12:217-232. Church, M. 1980. Records of recent geomorphological events, pp. 13- 29. In: R.A. Cullingford, D.A. Davidson, and J. Lewin (eds.), Timescale geomorphologyn si , Wiley, London. Churchill, J.H., C.T. HesC.Wd san . Smith. 1979. Measuremend an t computer modellin radionuclidf go e uptak mariny eb e sediments near a nuclear power reactor. Health Phys. 38:327-340.

Clague, J. J. , P.T. Bobrowsky, and T.S. Hamilton. 1994. A sand sheet deposited by the 1964 Alaska Tsunami at Port-Alberni, British-Columbia. Estuar. Coastal Shelf Sei. 38:413-421. Clark, E.H. II 1985. The off-site cost of soil erosion. J. Soil Water Conserv. 40:19-22. Clark, M.J. and F.B. Smith. 1988. Wet and dry deposition of Chernobyl releases. Mat. 332:245-249. Stahr. ClemensK d .an . 1994,G . Presen pasd tan t soil erosion rates in catchments of the Kraichgau Area (SW-Germany). Catena 22:153-168. Clifton, R.J d E.Ian . . Hamilton. 1982 e .applicatioTh f o n radioisotopes in the study of estuarine sedimentary processes. Estuar. Coast. Shelf Sei. 14:433-466. Cline, J.F d W.Han . . Richards. 1972. Radioactive strontiud an m cesiu n c-ultivatei m d abandonean d d plots. Health Phys. 23:317-324. Glint, G.M. and J. Dighton. 1992. Uptake and accumulation of radiocaesium by mycorrhizal and non-mycorrhizal heather plants. New Phytologist 121:555-561. Clymo, R.S. 1983. Peats 159-224. ,pp tn .I A.J . Core (ed.), Mires: swamps moord , an bogs .n Ecosystemfe , e worldth . f 4A ,o s Elsevier Yorkw ,Ne . Coard, M.A., S.M. Cousen, A.H. Cuttler, H.J. Dean, J.A. Dearing, T.I. Eglinton, A.M. Greaves, K.P. Lacey, P.E. O'Sullivan, D.A. Pickering, M.M. Rhead, J.K. Rodwell, and H. Simola. 1983. Paleolimnological studies of annually-laminated sediments in Loe Pool, Cornwall, U.K. Hydrobiologia 103:185-191.

139 Cockran, J.K. 1985. Particle mixing rate n sedimenti se th f o s 2l 239+2 l37 eastern equatorial Pacific: evidence from °Pu, *>pu and Cs distribution at MANOP sites. Geochim. Cosmochim. Acta 49:1195- 1210. Cockran, J.K. and J.K. Osmond. 1974. Gamma spectrometry of deep-sea cores and sediment accumulation rates. Deep Sea Res. 21:721- 737. Colacicco . OsbornT . AltK , .d ,D. an , 1989 . Economic damage from soil erosion. J. Soil Water Conserv. 44:35-39. Coleman, N.T., D. Craig, and R.J. Lewis. 1963. Ion exchange reactions of cesium. Soil Sei. Soc. Am, Proc. 27:287-289. Coleman, N.T., R.J. Lewis, and D. Craig. 1963. Sorption of cesium by soil and its displacement by salt solutions. Soil Sei. Soc. Am. Proc. 27:290-294. Colgan, P.A., P. McCann, E.J. McGee, and I.R. McAulay. 1993. Short and long-term losses of cesium-137 from peatland soils. Irish J. Agric. Food Res. 32:37-46.

Comans, R.N.J. e PrêterD . Haller. M ,P .d an 1991, . Sorptiof o n cesiu illiten mo : non-equilibrium behavio reversibilityd ran . Geochim. Cosmochim. Acta 55:433-440. Comans, R.N.J. and D. Hockley. 1992. Kinetics of cesium sorption on illite. Geocbim. Cosmochim. Acta 56:1157-1164. — Comans, R.N.J., J.J. Middleburg, J. Zonderhuis, R.J.W. Woittiez, G.J. OeLange, A.K. Das, and C.H. Van der Weijden. 1989. Mobilizatio radif no o caesiu porn mi e wate lakf ro e sediments. Nat. 367-369. Cook, C. 1990. The evaluation of soil movement rates in a closed watershed using Cs-13 tracera s a 7 . Unpublishe S ThesisM d , Washington State Univ., Pullman, Washington, USA. Cooper ,d J.R C.Man . . McHenry. 1987. Sediment depositios it d an n effects on a Mississippi River oxbow lake. Environ. Geol. Water Sei. 13:33-37. Cooper, C.M., F.R. Schiebe J.Cd .,an Ritchie. 1991inexpensivn A . e sampler for obtaining bulk sediment cores. Environ. Geol. Water Sei. 18{2) : 115-117 . Cooper, J.R., J.W. Gilliam, R.B. Daniels, and W.P. Robarge. 1987. Riparian area filters sa agriculturar sfo l sediment. Soil Sei. 51:416-420. J . SocAm . . Cooper, J.R., J.W. Gilliam T.Cd .,an Jacobs. 1986. Riparian areas sa a contro nonpoinf lo t pollution 166-190. ,pp D.L: ..Jn Correll (ed.), Watershed research perspectives, Smithsonian Institution Press, Washington, DC. Cooper, L.W., C.R. Olsen, O.K. Solomon, I.L. Larsen, R.B. Cook, and J.M. Grebmeir. 1991. Stable isotope oxygef so naturad nan d lan fallout radionuclides usetracinr dfo g runoff during snowmelt in an Arctic watershed. Water Resour. Res. 27:2171-2179. Coppinger, K.D., W.A. Reiners, I.e. Burke R.Kd ,.an Olson. t 1991Ne . erosio a sagebrus n o n h steppe landscap s determinea e y b d cesium-137 distribution. Soil Sei. Soc. Am. J. 55:254-258. Cornett, R.J. and L. Chant. 1984. ^-^PU residence times in freshwaters and accumulation in shield lake sediments. Can. J. Fish. Aquat. Sei. 45:407-415.

140 ChantCornettLink. . L D , d .,J. an 1984. ,R . Sedimentatio 2IOf n Po i b laurentian shield lake sediment. Water Pollut. Res . Can.J . 19:97-109. Cornett, R.J., L.A. Chant, B.A. Risto, and E. Bonvin. 1994. Identifying resuspended particles using isotope ratios. Hydrobiologia 284:69-77. Coughtrey, P.J., J.A. Kirton, and N.G. Mitchell. 1989. Transfer of radioactive caesium from soi o vegetatiot l d comparisoan n n with potassiu uplann mi d grasslands. Environ. Pollut. 62:281- 315.

Coughtrey, P.J. and M.C. Thorne. 1983. Radionuclide distribution and transport in terrestrial and aquatic ecosystems: a critical review. A.A. Balkema, Rotterdam. Cox, M.E. and B.L. Frankhauser. 1984. Distribution of fallout 137cesium in Hawaii. Health Phys. 46:65-71. Craft, C.B. and J. Richardson. 1993. Peat accretion and N, P, and organi C accumulatioc n nutrient-enrichei n d unenrichean d d peatland. Ecol. Applications 3:446-458. Craft, C.B., E.D. Seneca, and S.W. Broome. 1993. Vertical accretion in microtidal regularl d irregularlan y y flooded estuarine marshes. Estuar. Coast. Shelf Sei. 37:371-386. Cranwell, P.A. 1973. Branched-chain and cyclopropanoid acids in a recent sediment. Cheat. Geol. 11:307-313. Cranwell, P.A. 1976. Decomposition of aquatic biota and sediment formation: lipid component blue-greea tw f so n algal species and detritus resulting from microbial attack. Freshwater Biol. 6:481-488. Cranwell, P.A. 1977. Organic chemistry of Cam Loch (Sutherland) sediments. Chem. Geol. 20:205-221. Cremers, A., A. Eisen, P. De Prêter, and A. Maes. 1988. Quantitative analysis of radiocaesium retention in soils. Nat. 335:247-249. Cremers Eisen. A , Valcke. ,E ,A. Wauters. ,J , F.J. Sandallsd an , S.L. Gaudern. 1990. The sensitivity of upland soils to radiocesium contamination . 238-248 . Desment,pp G : .Jn . P , Nassimbeni, and M. Belli (eds. ), Transfer of radionuclides in natura d semi-naturaan l l environments, ProceedingC CE a f so workshop, Udine, Italy. Crete, M., M.A. Lefebvre, L. Zikovsky, and P. Walsh. 1992. Cadmium, lead, mercury and cesium-137 in fruticose lichens of Northern Quebec. Sei. Total Environ. 121:217-230. Crickmore, M.J., G.S. Tazioli, P.G. Appleby Oldfield. F d ,an . 1990. The use of nuclear techniques in sediment transport and sedimentation problems. IHP-III Project 5.2 SC-90/WS-49, 170 pp. UNESCO, Paris, France. Croraroy, H.L., W.A. Goldsmith, C.R. Phillips, and W.P. Bonner. 1967. Uptake of cesiura-137 from contaminated soil by selected grass crops. Radiât. Health Data Report 8:421-424. Crusius R.Fd an .. , J Anderson. 1990. 137Cs mobility inferred from 2IOPb and 239'240Pu analyse f laminateo s d lake sediments TransS .EO . 71:72. Crusius, J. and R.F. Anderson. 1991. Core compression and surficial sediment loss of lake sediments of high porosity caused by gravity coring. Limnol. Oceanogr. 36:1021-1031.

141 Cunha, I.I.L., C.s. Munita, R.P. . TeixeiraPaivaA d an , . 1993. Levels of cesium-137 in seawater and fish from the Brazilian Coast. Sei. Total Environ. 140:431-435.

Gushing, C.E. and D.G. Watson. 1974. Aquatic studies of Gable Mountain pond. BNWL-1884, 24 pp. Battelle Pacific Northwest Laboratories, Richland, WA. Cutshall, N.H., I.L. Larsen, and M.M. Nichols. 1981. Man-made radionuclides confirm rapid burial of kepone in James River sediments. Sei. 213:440-442. Czuczwa, J.M d R.Aan . . Kites. 1984. Environmental fatf o e combustion-generated polychlorinated dioxin d furansan s . Environ. Sei. Tech. 18:444-450. Dahlgaard, H. 1994. Sources of Cs-137, Sr-90 and Tc-99 in the East Greenland current. J. Environ. Radioact. 25:37-55. Dahlman, R.C S.Id .an . Auerbach. 1968. Preliminary estimatiof o n erosion and radiocesium redistribution in a fescue meadow. ORNL-TM-2343 k RidgOa , e National Laboratory k RidgeOa , , Tennessee. Dahlman, R.C., C.W. Francis. TamuraT d an ,. 1975. Radiocesium cycling in vegetation and soil, pp. 462-481. la t F.G. Howell, J.B. "Gentry d M.Han , . Smith (eds.), Mineral cyclinn i g southeastern ecosystems, USAEC Symposium Series, CONF-740513, US Atomic Energy Commission, Washington. ,DC Davidson, C.I., J.R. Harrington, M.J. Stephenson, M.C. Monaghan, J. Pudykiewicz, and W.R. Schell. 1987. Radioactive cesium from e Chernobyth l accidene Greenlanth n e i sheett ic d . Sei. 237:633-634. Davies ,. ShawG K.S d .an .1993 . Fixatio f Cs-13o n y soid b 7 an l estuaryk sedimenEs e th ,n tCumbriai Sei. ,UK . Total Environ. 132:71-92. Davis, F.W. 1985. Historical change n submergei s d macrophyte communities of upper Chesapeake Bay. Ecol. 66:981-983. Davis, J.J. 1963. s relationshiit Cesiu d an m o potassiut p n i m ecology, pp. 539-556. Im V. Schultz and A.W. Klement Jr. (eds.), Radioecology, Reinhold, New York. Davis, J.J. and R.F. Foster. 1958. Bioaccumulation of radioisotopes through aquatic food chains. Ecol. 39:137-535. Davis, M.B M.Sd .an . Ford. 1982. Sediment focusin Mirron i g r Lake, New Hampshire. Limnol. Oceanogr. 27:137-150. Davis, R.B., C.T. Hess, S.A. Norton, D.W. Hanson, K.D. Hoaglandd ,an D.S. Anderson. 1984. I37Cs and 210Pb dating of sediment from soft-water Englan w lakeNe n si d (U.S.A. d Scandinavia)an a , failur l37f eo C s dating. Chem. Geol. 44:151-185. Davis, R.B S.Ad .an . Norton. 1978. Paleolimnolog Englanw Ne x dsi f yo lakes, pp. 217-308. Im R.W. Hardy (ed.), The impact of urbanizatio Englanw Ne n no d lakes, selected technical papers, Vol. Ill, New England Council Water Center Dir., Boston, MA.

Davis, R.B., S.A. Norton, D.F. Brakke, F. Berge, and C.T. Hess. 1980. Atmospheric depositio Norwan i n y durin e pas0 th g30 t years as recorded in SNSF lake sediments. Part IV. Synthesis and comparison with New England, pp. 274-275. Im D. Drablos and A. Tollan (eds.), Proceedings international conference on ecological~impac acif to d precipitation, Sandefjord, Norway.

142 Davis, R.B., S.A. Norton, C.T. Hessd D.Fan , . Brakke. 1983. Paleolimnological reconstruction of the effect of atmospheric depositio f acid heavo n an d y e chemistrmetalth n o sd an y biolog w Englan f Ne lakeo y d Norway n i san d . Hydrobiologia 103:113-123. Davison Hilton. J , . Hamilton-Taylor. ,W ,J Kelly. ,M Livens. ,F . ,E Rigg, T.R. Carrick D.Ld ,an . Singleton. 1993transpore Th . f to Chernobyl derived caesium through two freshwater lakes in Cumbria, U.K Environ. .J . Radioact. 19:125-153. Davison, W., P. Spezzano, and J. Hilton. 1993. Remobilization of , caesium from freshwater sediments. J. Environ. Radioact. 19:109-124. Dawson, R. and E.K. Duursma. 1974. Distribution of radioisotopes between phytoplankton, sediment and sea water in a dialysis compartment system. Neth. J. Sea Res. 8:339-353. Day, D.G. and B.L. Campbell. 1986. Environmental caesium-137 as an indicato acceleratef ro d erosio sedimentatiod nan Birchamn ni s Creek, NSW. Centr r Resourcfo e d Environmentaan e l Studies, ANU, Canberra: Working Paper 1986/42. Day, L.R. and H.H. Zurape. 1986. Radioactivity in silt from the River Lea, England. Environ. Pollut. (Series B) 12:75-84. Dearing, J.A. 1983. Changing pattern sedimenf so t accumulatioa n i n small lak Scanian ei , Southern Sweden. Hydrobiologia 103:59- 64. Dearing, J.A. 1991. Lake sediment records of erosional processes. Hydrobiologia 214:99-106. Dearing, «J.A. 1992. Sediment yields and sources in a Welsh upland catchment during the past 800 years. Earth Surf. Proc. Landforas 17:1-22. Dearing, J.A., J.K. Einer, and C.M. Happey-Wood. 1981. Recent sediment flux and erosional processes in a Welsh upland lake- catchment base magnetin do c susceptibility measurements. Quat. Res. 16:356-372. Deevey, E.S 1988. .Jr . Estimatio downwarf no d leakage from Florida lakes. Limnol. Oceanogr. 33:1308-1320. de Jong C.B.M, . E , . Begg R.Gd an , . Kachanoski. 1983. Estimatef so soil erosion and deposition from some Saskatchewan soils. Can. J. Soil Sei. 63:607-617. de Jong, E. and R.G. Kachanoski. 1988. The importance of erosion in the carbon balanc prairif eo e soils. Can Soi. J . l Sei. 68:HI- 119.

d e. Villar H Jong d , J.Ran E. ,, . Bettany. 1982. Preliminary f 137investigationo o estimatCt s e us e e th erosio n o s n i n Saskatchewan. Can. J. Soil Sei. 62:673-683. de Jong, E. , C. Wang, and H.W. Rees. 1986. Soil distribution on three cultivate Brunswicw dNe k hillslopes calculated from 137Cs measurement, solum data and the USLE. Can. J. Soil Sei. 66:721-730. DeLaune, R.D. 1986. The use of 6 I3C signature of C-3 and C-4 plants in determining past depositional environments in rapidly' accreting marshee Mississippth f o s i River deltaic plain, Louisiana, U.S.A. Chen. Geol. 59:315-320. DeLaune, R.D., R.H. Baumann, and J.G. Gosselink. 1983. Relationship among vertical accretion, coastal submergence erosiod ,an n ni Louisiana Gulf Coast marsh Sedimentar. .J y Petrology 53:147- 157.

143 DeLaune, R.D., G.L. Jones and C.J. Smith. 1986. Radionuclide concentration Louisiann si a soil sedimentsd san . Health Phys. 51:239-244. DeLaune, R.D-, C.W. Lindau, R.S. Knox, and C.J. Smith. 1990. Fate of nitroge d phosphoruan n s enterin a Gulg f Coast fresh water lake cas:a e study. Water Resour. Bull. 26:621-631. DeLaune, R.D. and W.H. Patrick Jr. 1990. Nitrogen cycling in Louisiana Gulf Coast brackish marshes. Hydrobiologia 199:73- 79. DeLaune, R.D., W.H. Patrick Jr. d R.Jan , . Buresh. 1978. Sedimentation rates determine 137y b dC s datin a rapidl n i g y accreting salt marsh. Nat. 275:532-533. DeLaune, R.D., W.H. Patrick Jr., and S.R. Pezeshki. 1987. Foreseeable flooding and death of coastal wetland forest. Environ. Conserv. 14:129-133. DeLaune, R.D, W.H. Patrick C.Jd ,an . Smith. 1992. Marsh aggradation and sediment distribution along rapidly submerging Louisiana Gulf Coast. Environ. Geol. Water Sei. 20:57-64. DeLaune, R.D., C.N. Reddy W.Hd ,an . Patric . 1981kJr . Accumulation of plant nutrients and heavy metals through sedimentation processe d accretioan s Louisiana n i n a salt marsh. Estuar. 4:328-334. DeLaune, R.D., C.J. Smith W.Hd ,an . Patric 1986. kJr . Sedimentation patterns in a Gulf Coastal backbarrier marsh: response to increasing submergence. Earth Surf. Proc. Landforms 11:485-490. DeLaune, R.D., C.J. Smith, W.H. Patrick Jr., and H.H. Roberts. 1987. Rejuvenated marsd bay-bottoan h m accretio n o rapidln y subsiding Coastal Plain of the U.S. Gulf coast: a second-order effecemergine th f to g Atchafalaya delta. Estuar. Coast. Shelf Sei. 25:381-389.

DeLaune, R.D., C.J. Smith M.Nd ,an . Sarafyan. 1986. Nitrogen cycling in a freshwater marsh of Panicum hemitomon on the deltaic Mississippe plaith f no i River Ecol. .J . 74:249-256. Delle Ferretti. SiteO , ,A. Marchionni. ,V . PapucciC d an , . 1984.

Measurement Csof, ^'-^pu Panud in some coastal sediment 238

of Tyrrhenian I37 sea . Cooun. Eur. Communities, (Rep) EUR(CECED9), pp. 233-243. DeMaster, D.J., B.A. McKee, C.A. Nittrouer, D.C. Brewster P.Ed ,an . Biscaye. 1985. Rates of sediment reworking at the Hebble Site' based on measurements of Th-234, Cs-137 and Pb-210. Marine Geol. 66:133-148. De Prêter, P.M. 1990. Radiocesium retentio e aquaticth n i n , terrestrial and urban environment: a quantitative and unifying analysis. Doctoraatsproefschrif . 1990Nr t . Katholieke Universiteit te Leuven, Leuven, Belgium. De Roo, A.P.J trace a erosioI37n f a s Co sa .n e ri 1991 us n e stud.Th y in South Limburg (The Netherlands) and the influence of Chernobyl fallout. Hydrol. Processes 5:215-227. Derose, R.C., N.A. T.rustrum d P.Man , . Blaschke. 1993. Post- deforestation soil loss from steepland hillslope Taronkin si , New Zealand. Earth Surf. Proc. Landforms 18:131-144. Desloges, J.R. 1987. Paleohydrolog Belle th af yo Cool a river basin: an assessmen environmentaf o t l reconstruction. Ph.D. Thesis. Univ. British Columbia, Canada.

144 Desmet, G.M., L.R. Van Loon, and B.J. Howard. 1991. Chemical speciatio bioavailabilitd nan elementf yo environmene th n si t and their relevanc o radioecologyt e . Sei. Total Environ. 100:124. Dickman, M.D. and H.G. Thode. 1985. The rate of lake acidification in four lakes nort Lakf ho e Superio relationshis it d ran o pt downcore sulphur isotope ratios. Wate r SoiAi rl Pollut. 26:233-253. Dickman , H.G,M. . Thode . AndersonRao. R S , d ,an . 1988. Downcore sulphur isotope ratio and diatom inferred pH in an artificially acidified Canadian Shield lake. Environ. Pollut. 49:265-288. Dickson, J.H., D.A. Stewart Thompson. ,R Turner. ,G , M.S. Baxter, N.D. Drndarsky, and J. Rose. 1978. Palynology, paleomagnetism, and radiometric dating of Flandrian marine and freshwater . sediment Locf so h Lomond. Nat. 274:548-553. Digerfeldt, G., R. Battarbee, and L. Bengtsson. 1975. Report of annually laminated sediments in Lake Järlasjon, Nacka, Stockholm. Geologiska Foreningen Stockholsi m Forhand Lingar 97:29-40. Dighton, J., G.M. Glint and J. Poskitt. 1991. Uptake and accumulation of '37Cs by upland grassland soil fungi: A potential immobilizations pooC f lo . Mycol. Res. 95:1052-1056.

Dodd, J.D. and G.L. Van Amburg. 1970. Transfer to and distribution of '"cesium in the soil of two grassland habitats. Can. J. Sei. 50:121-129. Domanov, M.M. and A.E. Gorbunov. 1992. The prognosis of the field of cesium-13 uppee th rn 7i Blace layer th kf so Sea . Okeanologiya 32:253-256. Dominik, J. 1989. Application des radio-isotopes naturels at anthropogènes pour l'étud processes ede s sédiment aires dane sl Léman. Cashier Fac. Sei. Universit e Genèvd é e 19:83-95.' (French) Dominik . BurrusD , J.Pd J. ,an , . Vernet. 1987. Transpore th f o t environmental radionuclides in an alpine watershed. Earth Planet. Sei. Lett. 84:165-180. Dominik, J., U. Förstner, A. Hangini, and H. Reineck. 1978. 710Pb and 137Cs chronology of heavy metal pollution in a sediment core from the German Bight (North Sea) Senckenbergiana Marit 10:213-227. Dominik, J., J.L. Loizeau, and D. Span. 1992. Radioisotopic evidence of perturbation f recteo s n sedimentary record n lakesi s a : wor f cautioo d n from climate studies. Clim. Dynamics 6:145- 152. Dominik . Mangini A . Müller G , d J. ,an ,. 1981. Determinatiof o n recent deposition rate Lakn si e Constance with radioisotopic methods. Sedimentology 28:653-677. Span. DominikD d . an 1992 . ,J fate .Chernobyf Th eo l cesium-13n 7i Lake Lugano. Aquat. Sei. 54:238-254. d K,ODörran .. MünnichH , . 1987. Spatial distributio f soio n l l37Cs and lî4Cs in West Germany after Chernobyl. Naturwissenschaften 74:249-251. K.Od Dörran . . Münnich,H . 1989. Downward movemen soif to l organic matter and its influence on trace element transport (Pb-210, Cs-137) in soil. Radiocarbon 31:655-663.

145 Dörr, H. and K.O. Münnich. 1991. Lead and cesium transport in European forest soils. Water Air Soil Pollut. 57:809-818. Dregne, H.E. 1990. Erosion and soil productivity in Africa. J. Soil Water Conserv. 45:431-436. Dregne, H.E. 1992. Erosio soid nan l productivit Asian i y . Soi.J l Water Conserv. 47:8-13. Drndarski, N and M. Krizman. 1994. Radioisotopes in periphyton and sediments froe Kolubarth m atributariest i Rive d an r . Water Res. 28:1471-1474. Durham, R.WS.Rd .an . Joshi. 1980a. Recent sedimentation rates, 210Pb fluxes, and particle settling velocities in Lake Huron, Laurentian Great Lakes. Cheat. Geol. 31:53-66.

Durham, R.W. and S.R. Joshi. 1980b. The 2l°Pb and I37cs profiles in sediment cores from Lake Matagam d Quevillonan i , northwest Quebec, Canada. Can .Eart. J h Sei. 17:1746-1750. Durham, R.W S.Rd .an . Joshi. 1980c. Radioactive datin f sedimeno g t cores from four contiguous lake Saskatchewann si , Canada. Sei. Total Environ. 15:65-71. Durham, R.W S.Rd .an . Joshi. 1981. Sedimentation rate western i s n

Nipigon Bay, Lake Superior using th°Peb method. Sei. Total Environ. 22:51-59. 2l Durham, R.W. and S.R. Joshi. 1984a. Dose equivalent commitments from fallout radionuclide opee th n n waterGreae si th tf so Lakes. 1973-1981. Environ. Monit. Assessment 4:405-417. Durham, R.W. and S.R. Joshi. 1984b. Lead-210 dating of sediments from some northern Ontario lakes 75-85. ,pp m W.C.I . Mahaney (ed.), Quaternary dating methods, Elsevier, Amsterdam. Durham, R.W., S.R. Joshi R.Jd ,an . Allan. 1980. Radioactive dating of sediment cores from four contiguous lake Saskatchewann si , Canada. Sei. Total Environ. 15:65-71. Durham, R.W. and B.C. Oliver. 1983. History of Lake Ontario contamination from the Niagara River sediment radiodating and chlorinated hydrocarbons analysis. J. Great Lakes Res. 9:160- 168. Duursma, E.K C.Jd .an . Bosch. 1970. Theoretical, experimentad an l field studies concerning diffusio f radioisotopeo n n i s sediment suspended san d particle seae th . f so Par method: tB s and experiments. Resa NethSe . . .J 4:395-469 . Duursma, E.K. and D. Eisma. 1973. Theoretical experimental and field studies concernin moleculae gth r diffusio radioisotopef no n si sediment d suspendesan d solid particle e seath . n si Par : C t Application fielo st d studies .Resa NetSe . . hJ 6:265-284 . Duursma Hoede. ,C E.Kd .an 1967. Theoretical experimenta field lan d studies concernin moleculae gth r diffusio radioisotopef no n si sediment d suspendean s d solid particle e seath . n i sPar : tA theories and mathematical calculations. Neth. J. Sea Res. 3 .-423-457. Eadie, B.J. and J.A. Robbins. 1987. The role of particulate matter movemene inth f contaminantto Greae th tn si Lakes . 319,pp - R.A364: In . . Hite S.Jd san . Eisenreich (eds.), Sourced san fates of aquatic pollutants, American Chemical Society, Washington. ,DC

146 Eakins, J.D d R.San . . Cambray. 1985. Studie f environmentao s l radioactivit Cumbrian yi chronolog,e Parth : t6 dischargf yo e of caesium-137, plutonium d americium-24an , 1 from BNFL Sellafield, as recorded in lake sediments. AERE-R-11182. united Kingdom Atomic Energy Authority Report, Harwell, UK.

Eakins, J.D., R.S. Cambray, K.C. Chambers A.Ed ,an . Lally. 1984e .Th transfe f o naturar d artificiaan l l radionuclideo t s Brotherswater s frocatchmentit m . 125-144pp , m I E.Y. . Hawort d J.W.Gan h . Lund (eds.), Lake sedimend an t environmental history, Univ. Minnesota Press, Minneapolis. ,MN Eakins, J.D. and R.T. Morrison. 1978. A new procedure for the determinatio f lead-21o n n lakd marini 0 an e e sediments. J . Appl. Radiât. Isot. 29:531-536. Eckblad, J.W., N.L. Peterson, K. Ostlie, and A. Temte. 1977. The' morphometry, benthos and sedimentation rates of a floodplain in Pool 9 of the upper Mississippi River. Am. Midland Naturalist 97:433-443. Edberg, N. 1980. Determination of recent sedimentation rates in lakey sCsb . Vatten 36:35-44. l37 Edgington, D.N D.Md -an . Nelson. 1986 persistence .Th pollutantf eo s in large lakes lessone :th s -from stud radioactivityf yo . ,pp 250-266. Im T.H. Sibley and C. Myttenaere (eds.), Application of distribution coefficients to radioecological assessment models, Elsevier, London. Edgington, D.N., J.C. Ritchie J.Ad ,an . Robbins. 1975. Commentn so the paper: "Us riverf eo predico st t accumulatio sedimentn ni s of radionuclides discharged from nuclear power plants. P y "b Plato. Health Phys. 29:429-431. Edgington, D.N. and J.A. Robbins. 1974a. Determination of recent sedimentation rates in Lake Michigan using Pb-210 and Cs-137, pp. 39—62. In: Radiological and environmental research division annual report, ecology, January-December 1973, Argonne National Laboratory, Argonne. ,IL Edgington, D.N J.Ad .an . Robbins. 1974b applicatioe .Th naturaf no l and fallout radionuclides to the studies of Lake Michigan, pp. 443-458 : ProceedinIn . g conferenc n nucleao e r methodn i s environmental research ERDS ,U A Conference 740701 EnergS ,U y Research and Development Authority, Washington, DC. Edgington, D.N J.Ad .an . Robbins. 1976a behavioe .Th plutoniuf ro m and other long-lived radionuclide n Laki s e Michiga. II n Pattern depositiof so sedimentsn ni 245-260. ,pp Impact: .In s of nuclear releases into the aquatic environment, International Atomic Energy Agency, Vienna, Austria. Edgington, D.N. and J.A. Robbins. 1976b. Patterns of deposition of natura d fallouan l t radionuclide Lakn si e Michiga theid nan r relation to limnological processes, pp. 705-729. Im J.O. Nriagu (ed.), Environmental biochemistry, volum : meta2 e l transfe d ecologicaan r l mass balances n ArboAn , r Science Publishers Arborn ,An . ,MI Edgington, D.N. and J.A. Robbins. 1976c. Records of lead deposition in Lake Michigan sediments since 1800. Environ. Sei. Tech. 10:266-274.

Edgington, D.N J.Ad an .. Robbins. 1976d. Pattern depositiof so f no radionuclides in sediments, pp. 1-12. In: Symposium on nonbiological transpor transformatiod tan pollutantf o n n o s land and water: processes and critical data required for predictive description, Gaithersburg. ,MD

147 Edgington, D.N J.Ad .an . Bobbins. 1977. Radionuclide geochronology and pollution history in lake sediment. Trans. Am. Nucl. Sei. 27:117. Edgington, D.N. and J.A. Robbins. 1979. Reply to Appleby and Oldfield (1979). Environ. Sei. Tech. 13:480-482. Edgington, D.N J.Ad an . . Robbins. 1988. Time scale f sedimeno s t focussing in Lake Michigan as revealed by measurement of fallout Cs-137. Im D. Imboden (ed.). Functional and structural properties of large lakes, Societas Internationalis Limnologiue Symposium, Konstunz, Germany. Edgington, D.N J.Ad an . . Robbins. 1990. Time scale f sedimeno s t focussing in Lake Michigan as revealed by measurements of fallout Cs-137, pp. 210-223. In: M. Tilzer (ed.), Large Lakes: ecological structure and function. Science Technology, Madison, WI. Edgington, D.M., J.A. Robbins d J.oan , . Karttunen. 1974e Th . distribution of Pb-210 and stable lead in Lake Michigan sediments . 63-76 pp ,: Radiologica In . d environmentaan l l research division annual report, Ecology, January-December 1973, Argonne National Laboratory, Argonne, IL. Edgington, D.N., J. Val Klump, J.A. Robbins, Y.S. Kusner, V.D. Pampura, and I.V. Sandimmirov 1991. Sedimentation rates, residence time, and radionuclide inventories in Lake Baikal from 2IOl37 d sedimenn PCi ban s t cores. Mat. 350:601-604. Edwards . 1980K , . Runof d soi an fe wheal th los n tw i sNe bel f o t South Hales, pp. 94—98. In: IAHS proceedings of the agricultural engineering conference. Effler, S.W. 1987. The impact of a chlor-alkali plant on Onondaga Lake and adjoining systems. Water Air Soil Pollut. 33:85-115. Effler S.W. and C.F. Carter. 1987. Spatial variability in selected physical characteristic d processean s n Crosi s s Lakew Ne , York. Water Resour. Bull. 23:243-249. Effler, S.W., M.C. Rand, and T.A. Taraayo. 1979. The effect of heavy metals and other pollutants on the sediments of Onondago Lake. Wate Soir rAi l Pollut. 12:117-134. Ehlers Nagorny. K , , J. Schmidt . ,P Stieve . ,Zietlow. B K d ,an . 1993. Storm surge deposits in North Sea salt marshes dated by Cs-134 and Cs-137 determination Coast. .J . Res. 9:698-701. Elliott, G.L., B.L. Campbell R.Jd .,an Loughran. 1984. Correlation of erosion and erodibility assessments using Caesium-137. J. Soil Conserv. (Mew South Hales) 40:24-29.

Elliott, G.L., B.L. Campbell, and R.J. Loughran. 1990. Correlation of erosion measuremen soid tan l caesium-137 content Appl. .J . Radiât. Isot. 41:713-717. Elliott, G.L. and B.E. Cole-Clark. 1993. Estimates of erosion on potato lands on Krasnozems at Dorrigo, N.S.W. using the caesium-137 technique. Aust. J. Soil Res. 31:209-223. Elliott, G.L., R.D. Lang, and B.L. Campbell. 1983. The association of tree species, landform, soil erosiod an s n Narrabeeo n n sandstone wes f Puttyo t w SoutNe , h Wales. Aust . EcolJ . . 8:321-331. . KanamoriS d Ellisan . .J , 1977. Water pollution studie Lakn so e Illawarra III. Distribution of heavy metals in sediments. Aust Marin. .J e Freshwater Res. 28:485-496.

148 Ely, L.L., R.H. Webb, and Y. Enzel, 1992. Accuracy of post-bomb l37Cs datinn i an C dU g fluvial deposits. Quat. Res. 38:196-204. Engstrom, D.R., E.B. Swain d J.Can , . Kingston. 1985A . palaeolimnological record of human disturbance from Harvey's Lake, Vermont: geochemistry, pigmen diatomsd tan . Freshwater Biol. 15:261-288. Entry, J.A., P.T. Rygiewicz W.Hd ,an . Birmingham. 1993. Accumulation of cesium-13 strontivun-9d 7an Ponderosn 0i a pin Montered ean y pine seedlings Environ. .J . Qual. 22:742-746. Erten, H.N., H.R Guntenn .vo Rössler. ,E Strum. M d ,.an 1985. Dating the sediments of Lake Zurich (Switzerland) with 2l°Pb and 137Cs. Schweiz Hydrol. .Z . 47:5-11. Erten, N.N., S. Aksoyoglu, and H. Gokturk. 1988. Sorption/desorption of caesiu clan soid o m an yl fraction from various regionf so Turkey. Sei. Total Environ. 69:269-296. Erten, N.N. . AksoyogluS , . HahpogluS ,. GokturkH d an , . 1988. Sorption of caesium and strontium on montmorillonite and kaolinite. Radiochimica Acta 44/45:147-151. Essington, E.H. and E.M. Romney. 1985. Mobilization of 137Cs during rainfall simulation studie Nevade th t asa Test- 35 Site . ,pp L.J: In .. Lan38 e (ed Proceeding) . rainfale th f so l simulator, workshop, Society for Range Management, Denver, CO. Evans, D.W., J.J. Alberts, and R.A. Clark III. 1983. Reversible ion- exchange fixation of cesium-137 leading to mobilization from reservoir sediments. Geochia. Cosmochim. Acta 47:1041-1049. Evans, E.J. and A.I. Dekker. 1966a. Plant uptake of Cs-137 from nine Canadian soils. Can Soi. .J l Sei. 46:167-176. Evans, E.J A.Id .an . Dekker. 1966b. Fixatio releasd an n Cs-13f eo 7 in soils and soil separates. Can. J. Soil Sei. 46:217-222. Evans, H.E., D.C. Lasenby, and P.J. Dillon. 1986. The effect of core compressio e measurementh n o n f zino t c concentratiod an n anthropogenic burden n i laks e sediments. Hydrobiologia 132:185-192.

Evans, R.D F.Hd .an . Rigler. 1983 .tesA lead-21f to 0e datinth r fo g measurement of whole lake soft sediment accumulation. Can. J. Fish. Aquat, Sei. 40:506-515. Eyman, L.D. and N.R. Kevern. 1975. Cesium-137 and stable cesium in a hypereutrophic lake. Health Phys. 28:549-555. Farmer, J.G. 1977 determinatioe .Th sedimentatiof no n rate Lakn si e Ontario using 210Pb dating methods. Can Eart. .J h Sei. 15:431- 437. Farmer, J.G. 1978. Lead concentration profile n lead-21i s 0 dated Lake Ontario sediment cores. Sei. Total Environ. 10:117-127. Farmer, J.G. 1983. Metal pollution in marine sediment cores from the west coas Scotlandf to . Marine Environ. Res. 8:1-28. Farmer, J.G., D.S. Swan, and M.S. Baxter. 1980. Records and sources of metal pollutant datea n si d Loch Lomond sediment core. Sei. Total Environ. 16:131-147. Favarger, P. and J. Vernet. 1979. L'isotope l37Cs utilisé comme dateur de la pollution des sédiments lacustres. Arch. Sei. 32:25-41. (French)

149 Feely, H.W., H.L. Volchok, E.P. Hardy, Jr. L.Ed ,an . Toonkel. 1978. Worldwide depositio r throug"S f o nh 1976 Cbem. Am . . Soc. .J 12:808-809. Feijtel, T.C., R.D. DeLaune, and W.H. Patrick Jr. 1985. Carbon flow in coastal Louisiana. Marine Ecol. Progress Series 24:255-260. Feijtel, T.C., R.D. DeLaune d W.Han , . Patric . 1988aJr k . Biogeochemical control on metal distribution and accumulation in Louisiana sediments Environ. .J . Qual. 17:88-94. Feijtel, T.C., R.D. DeLaune W.Hd an , . Patric . 1988bkJr . Seasonal pore water dynamic marshen si Baratarif so a Basin, Louisiana. Soil Sei. 52:59-67. SocJ . .Am .

Fisher, J.B., W.J. Lick, P.L. McCall d J.Aan , . Robbins. 1980. Vertical mixin lakf go e sediment tubificiy sb d Oligochaetes. J. Geophys. Res. 85:3998-4006 Fleishman, D.G., V.A. Nikiforov, A.A. Saulus, and V.T. Komov. 1994. Cs-137 in fish of some lakes and rivers of the Bryansk Region and North-West Russi n 1990-1992i a . EnvironJ . . Radioact. 24:145-158. Flowers R.W, . J . R , Battarbee . NatkanskiJ , . RippeyB , d P.Gan , . Appleby. 1988. The recent acidification of large Scottish Loch located partly within a national nature reserve and site of special scientific interest. J. Appl. Ecol. 25:715-724. Flowers, R.J., A.C. Stevenson, J.A. Dearing, I.D.L. Foster, A. Airey . RippeyB , , J.P.F. Wilson d P.Gan , . Appleby. 1989. Catchment disturbance inferred from paleolimnological studies of three contrasted sub-humid environments in Morocco. J. Paleolimnology 1:293-322.

Flynn, W.W. 1970. A rapid solvent extraction method of the determination of caesium-137 in environmental materials. Analytics Chimica Acta 50:365-373. Förstner, U. 1987. Sediment-associated contaminants - an overview of scientific bases for devetoping remedial options. Hydrobiologia 149:221-246. Forsyth, T.J. 1994. The use of cesium-137 measurements of soil erosion and farmers' perceptions to indicate land degradation amongst shifting cultivator northern i s n Thailand. Mountain Research and Development 14:229-244. Foster, G.R. 1991. Advances in wind and water erosion prediction. J. Soil Water Conserv. 46:27-29. Foster, G.R T.Ed .an . Hakonson. 1984. Predicted erosio sedimend nan t delivery of fallout plutonium. J. Environ. Qual. 13:595-602. Foster, I.D.L., J„A. Dearing, and P.G. Appleby. 1986. Historical trend n catchmeni s t sediment yields a cas: e studn i y reconstruction from lake-sediment records in Warwickshire, UK. Hydrological Sei. J. 31:427-443. Foster, I.D.L., J.A. Dearing, A. Simpson, A.D. Carter, and P.G. Appleby. 1985. Lake catchment based studies of erosion and denudation in the Merevale Catchment, Warwickshire, U.K. Earth Surf. Processes Landforms 10:45-68. Foster, I.D.L., R. Grew, and J. Dearing. 1990. Magnitude and frequency of sediment transport in agricultural catchments: a paired lake-catchment stud Midlann yi d England 153-171. ,pp . Boardman. J m I , I.D.L. Foster J.Ad ,an . Dearing (eds.), Soil erosion of agricultural land, Wiley, London.

150 FraleyChavez. G , O.Dd ,L. ,an . Markham. 1993. Seasonal variations in depositio d retentioan n cerium-14f no d cesium-131an n i 4 cool desert vegetation. J. Environ. Radioact. 21:203-212. France, R.L. . SvobodaJ , d H.Wan , . Taylor. 1993. Latitudinal distribution of cesium-137 fallout in 1990 on Saxifraga- Oppositifolia from Elles Mere Island Canada. Can . BotJ . . 71:708-711. Francis, C.W. and F.S. Brinkley. 1976. Preferential adsorption of 137Cs to micaceous minerals in contaminated freshwater sediments. Nat. 260:511-513. FraleyChavez. G , O.Dd ,L. ,an . Markham. 1993. Seasonal variations in deposition and retention of cerium-141 and cesium-134 in cool desert vegetation. J. Environ. Radioact. 21:203-212. Franklin, R.E., P.L. Gersper Holowaychuk. N d ,an . 1967. Analysif so gamma-ray spectra from soil plantsd san effect. :II treef so s e distributioth n o f fallouto n . Soil Sei. Soc . ProcAm . . 31:43-45. Fredericks, D.J. . NorrisV , S.Jd an , . Perrens. 1988. Estimating erosion using caesium-137: I. measuring caesium-137 activity in soil. IAHS Publ. No. 174:225-231.

Fredericks, D.J. and S.J. Perrens. 1988. Estimating erosion using caesium-137: II. Estimating rates of soil loss. IAHS Publ. No. 174:233-240. Fredriksson Eriksson. B , ,L. , B.G. Rasmuson Eduarson. ,K Gähne. ,B , . K anLowd . 1958. Studie f o soil-plant-animas l interrelationships with respect to fission products, peaceful uses of atomic energy, pp. 449-470. In: Proceedings 2nd international conference, United Nations, Geneva, Switzerland. Frere, M.H H.Jd .an . Robert 1963. sJr lose .strontiumf Th so 50 from small cultivated watersheds. Soil Sei. Soc. Am. Proc. 27:82- 83. Frid, A.S V.Sd .an . Grakovskiy. 1988. Diffusio l37f n soilsCo ni s . Pochvovedeniy 78-86: e2 . Frissel, Pennders. M.JR d .an . 1983 .accumulatioe Modelth r sfo d nan migratio *Srf no , l37Cs, a» +2 uppee *'A«pd th an umrn i layef ro soils, pp. 63-72. la: P.J. Coughtrey, J.N.B. Bell, and T.M. Roberts (eds.). Ecological aspects of radionuclide release. Blackwell, Oxford. Frissel, M.J., J.F. Soutjesdijk, A.C. Hoolwijk, . and H.W. Koster. 1987. The Cs-137 contamination of soils in the Netherlands and its consequences for the contamination of crop products. Neth. J. Agr. Sei. 35:339-346. Fröhlich . FrankeT , . GellermannK. R , . HerbertD d an , . 1987. Silicon-3 differenn i 2 t aquifer type d implicationan s r fo s ground water dating. Proc. Isotope Techniques in Water Resources Development, pp. 149-163. International Atomic Energy Agency, Vienna, Austria. Fröhlich, K. and D.E. Walling. 1992. The use of radionuclides in investigations of erosion and sediment delivery in the Polish Flysh Carpathians. IAHS Publ. No. 209:61-76. Fujikawa, Y., M. Fukui, D.J. Drew, and T.T Vandergraaf. 1993. Large analysis of the migration of instantaneously injected cesium in artificial Bonneu fractured c tLa Granitef so , Manitoba, Canada. J. Contain. Hydrol. 14:207-232.

151 Gaggino, G.F., G. Parise, G. Premazzi, and A. Provini. 1984. Trends n evolutioi f nutrienno tracd an t e element sedimentn i s s from 13 Italian subalpine lakes ove e las years0 th r 3 t . Proceedings third international symposium on the interaction between sediment waterd an s , Geneva, Switzerland . 135-138pp , .

Galloway, J.N. and G.E. Likens. 1979. Atmospheric enhancement and metal deposition in Adirondack lake sediment. Limnol. Oceanogr. 24:427-433. Garcia-Olivares, A. and A. Aguero. 1993. A model for the behavior of 137 watershen Ci s d scenarios . J Contant. . Hydrol. 13:183-211.

Garcla-Tenorio, R, C.I. Sanches-Angulo, M. Garcia-Léon, J.M. Abril and F. El-Daoushy. 1992. The use of l37Cs in marine and lacustrine sediment dating. Nuclear Geophy. 6:395-403.

Garland, J.A., W.A. McKay, P.J. Burton, and R.S. Cambray. 1990. Studies of environmental radioactivity on the coast of Northern Ireland. Nucl. Energy 29:205-233.

Garland, J.A., W.A. McKay, R.S. Cambray, and P.J. Burton. 1989. .Man- made radionuclides in the environment of Dumfries and Galloway. Nucl. Energy 28:369-392. Garnham, G.W., G.A. Codd G.Md an . , Gadd. 1993. Uptak f cobaleo d an t cesiu microalgal-clay mb cyanobacterial-clad an y y mixtures. Microbiol. Ecol. 25:71-82. Garrett, A.R. Jr, S.L. Cummings, and J.E. Régnier. 1971. Accumulation of 137Cs and "Sr by Florida forages in a uniform environment. Health Phys. 21:67-70. Garten, C.T. Jr, J.B. Gentry, J.E. Finder III, R.R. Scharitz, and M.H. Smith. 1975. Radiocaesium dynamic a contaminate n i s d floodplain ecosyste southeastere th n mi n united States. pp , 331-347. In: Impact of nuclear releases into aquatic environments, International Atomic Energy Agency, Vienna, Geng, G.Q D.Rd .an . Coote. 1991 residuae Th . l effect f soio s l loss e chemicaoth n physicad an l l qualit f threyo e soils. Geoderma 48:415-429.

Gerdol, R., S. Degetto, D. Mazzotta, and G. Vecchiata. 1994. The vertical distributio f Cs-13no 7 derived from Chernobyl fall- e uppermosth n i t tou Sphagnum peatlando layetw e th f o rn i s southern Alps. Water, Air, Soil Pollut. 75:93-106. Gersper, P.L. 1970. Effect of American beech trees on the gamma radioactivity of soils. Soil Sei. Soc. Am. Proc. 34ï318-323.

Gerzabek, M.H. and S.M. Ullah. 1988. Über die Verteilung van 137Cs in den Korngrö Benfraktionen zweier kontaminierter Bödene Di . Bodenkultur 39:293-297. (German) Ghuman, G.S., B.C. Motes, S.J. Fernandez, K.W. Guardipee, G.W. Mcmanus, C.M. Wilcox F.Jd an ., Weesner. 1993. Distributiof no antimony-125, cesium-137 iodine-12d an ,e soi th ln i 9plan t system aroun nucleaa d r fuel reprocessing plant . J Environ. . Radioact. 21:161-176. Giani, L., H. Gebhardt, W. Gusy, and H. Helmers. 1987. Verhalten einiger radioaktiver nuklide (freigesetzt durch den reaktorunfal n i Tschernobyll n i typische) n Böden Norddeutschlands . Z Pflanzenernahr. . Bodenk. 30:103-107. (German) Gibley. BradleyS , D.Ed J. , an , . Walling. 1987 depositioe Th . f no caesiu grasslann o 7 msita 13 t n Sedi a W England followine gth Chernobyl accident. Grass Forage Sei. 42:439-442.

152 Gilbert, R. and J.R. Desloges. 1987. Sediments of ice-dammed, self-draining Ape Lake, British Columbia. Can. J. Earth Sei. 14:

Gill, A.C., J.R. McHenry J.Cd an ,. Ritchie. 1976. Efficiencf o y nitrogen, carbon, and phosphorus retention by small agricultural reservoirs. J. Environ. Qual. 5:310-315. Godoy, J.M., J.R.D. Guimaraes d Z.Lan , . Carvalho. 1993. Cs-137 pre-concentration from water samples using a Prussian Blue impregnated ion—exchanger Environ. .J . Radioact. 20:213-219. Goldberg, E.D. 1963. Geochronology with lead-210 radioactive dating. STI/PUB/68 121-131. ,pp , International Atomic Energy Agency, Vienna, Austria. Goldberg, Koide. E.DM d .an . 1962. Geochronological studie deef so p a sedimente se ionium/thoriuth y b s m method. Geochem. Cosmochim. Acta 26:417-450. Golos, V.N., L.F. Litvin d A.Nan ,. Silant'yev. f 1990o e Us . radioisotope methods to estimate the intensity of soil erosion, pp. 190-201. Im Study of dangerous natural phenomena: method d resultsan s .A collectio f scientifio n c papers. MGU, Moscow. Goreau, T.J. 1977. Qualitative effect f sedimeno s t mixinn o g stratigraphy and biochemistry: a signal theory approach. Nat. 265:525-526. d J.EGorhaman .. E Sanger, . 1976. Fossilized pigments a s stratigraphie indicator culturaf so l eutrophicatio Shagawn ni a Lake northeastern, Minnesota. Geol. Soc. Am. Bull. 87:1638-1642. Gottgens, J.F. and T.L. Crisman. 1993. Quantitative impacts of lake- level stabilizatio materian o n l transfer between wated an r sedimen Newmann i t s Lake, Florida. Can .Fish. J . Aquat. Sei. 50:1610-1616. Graham, E.R. 1963. Factors affecting Sr-85 and 1-131 removal by runoff water. Wate Sewagd ran e Works 110:407-410. Graham, E.R D.Dd .an . Killion. 1962. Soil colloid factoa s a sn i r the uptake of cobalt, caesium and strontium in plants. Soil Sei. Soc. Am. Proc. 26:545-547. Graustein, W.C K.Kd .an . Turekian.d 1986an r .ai 2ll37 d °Pn Can i bs soil measur e rate th d verticae an s l profil f aerosoo e l scavenging Geophys. .J . Res. 91:14355-14366. Grebmeier, J.M., L.W. Cooper LarsonL ,I. Sous. ,C C.Rd ,an . Olsen. 1993. Cesium-137 inventories in Alaskan tundra, lake and marine sediment: An indicator of recent organic matter transport. Report No, IAEA-SM-329/21/0 (Conf .-930412-1), 22pp. Green, N., B.T. Wilkins, and D.J. Hammond. 1994. The transfer of Cs-137 and Sr-90 along the soil-pasture-cows' milk pathway in an are lanf ao d reclaimed froseae mth Environ . J . Radioact. 23:151-170. Gregorich, E.G D.Wd .an . Anderson. 1985. Effect cultivatiof so d nan erosion on four toposeguences in the Canadian prairies. Geoderma 36:343-354.

Griffith . M 1978, . Specific blue-green algal carotenoidn i s sediments of Esthwaite Water. Limnol. Oceanogr. 23:777-784. Grimes, J.A S.Rd .an . Rushforth. 1983. Diatom surfacf so e sediments of Utah Lake, Utah, U.S.A. Hydrobiologia 99:161-174.

153 Grovers, G., T.A. Quine and D.E. Walling. 1993. The effect of water erosio n hillslopo n e profile development a compariso: f o n field observation d modean s l results . 285-300. pp ,S : In . Wicherek (ed.), Framland erosion in -temperate plains environment and hills, Elsever, London. Grzybowska, D.- and G.J. Soszka. 1978.w Sr and 137Cs contamination leve Zarnowien li c lake. Bulleti L'Académie nd e Polonaiss ede Sciences Seri Sciences ede s Biologique 26:751-757I I . sCl . Gschwend, P.M R.Ad an . . Hites. 1981. Fluxe polycyclif so c aromatic hydrocarbons to marine and lacustrine sediments in the northeastern united States. Geochim. Cosmochim. Acta 45:2359- 2367. Guinasso ,D.Rd N.Lan .r .J Schink . 1975. Quantitative estimatef so 'biological mixing rates in abyssal sediments. J. Geophys. Res. 80:3032-3043. Gulinck, H., I. Vanden Berghe, and E. Abts. 1988. Dynamics, interactions and connectivity of linear elements in rural landscape centraf so l Belgium. Planning opportunities- 89 , ,pp 91. In: K.F. Schreiber (ed.), Connectivity in landscape ecology, Proceeding Internationad 2n e th f so l Seminae th f ro International Association for Landscape Ecology, Munster, Germany. Gutierrez, M. and H.R. Fuentes. 1991. Competitive adsorption of cesium, cobalt and strontium in conditioned clayey soil suspensions. J. Environ. Radioact. 13:271-282.

Haghiri . 1970,F . Fat strontium-9f eo soiln 0i , plants waterd ,an . Ohio Report 55:74-77. Hairr 1974. ,L investigation .A factorf no s influencing radiocesium cycling in estuarine sediments in the Hudson River. Ph.D. Thesis Yorw ,Ne k Univ. Yorkw ,Ne . Hâkanson, L. 1980. An ecological risk index for aquatic pollution control .sedimentologicaA l approach. Water Res. 14:975-1001. Hâkanson, L. and T. Andersson. 1992. Remedial measures against radioactive caesiu n Swedisi m h lake fish after Chernobyl. Aquat. Sei. 54:141-164. , KällströmHâkansonA d an . L ., 1978 n .equatioA f stato nr fo e biologically active lake sediment and its implications for interpretation sedimenf so t data. Sedimentology 25:205-226. Hakenson, T.E. and F.W. Wicker. 1975. Cesium kinetics in a montane lake ecosystem. Health Phys. 28:699-706. Hakkinen, U. and E. Lakanen. 1968. Strontium 90 and caesium 137 in some Finnish soil profiles. Ann. Agric. Fenn. 7:123-126.

Halldin, S. , A. Rodhe, and B. Bjurman. 1990. Urban storm water transport and wash-off of caesium-137 after the Chernobyl accident. Wate Soir rAi l Pollut. 49:139-158. Hamilton, E.I. and K.R. Clarke. 1984. The recent sedimentation history of the Esk estuary Cumbria, U.K.: the application of radiochronology. Sei. Total Environ. 35:325-386. Hansen, H.J.M. and A. Aarkrog. 1990. A different surface geology in Denmark e Faroth , e island d Greenlanan s d influencee th s radiological contamination of drinking water. Water Res. 24:1137-1141. . WarburtoJ Harbord an . .J , 1993. Relative rate f glaciao s d an l nonglacial erosio Alpinn ni e environments. Arctic A.R. 25:1-7.

154 Hardy, E.P. 1975. Regional uniformity of cumulative radionuclides fallout. HASL-288. Health and Safety Laboratory, New York. Hardy, E.P., H.D. Livingston, J.C. Burke, and H.L. Volchok. 1978. Time pattern of off—site plutonium contamination from Rocky Flats Plant by lake sediment analyses. EML-342, pp. 1-123 to 1-146. Environmental Monitoring Laboratory, New York. Hardy, E.P., M.W. Meyer, J.S. Alien d L.Tan , . Alexander. 1968. Strontium-90 on the earth's surface. Nat. 219:584-587. Harper, R.J. and R.J, Gilkes. 1994. Evaluation of the Cs-137 techniques for estimating wind erosion losses for some sandy Western Australian soils, Aust Soi. .J l Res. 32:1369-1387. Haselwandter, V.K. 1977. Radioaktives Cäsium (Cs 137) in fruchtkörpern verschiedener Basidiomycetes. Zeitschr. F. Pilzkunde 43:323-326. (German) Haselwandter, V.K. 1978. Accumulation of radioactive nuclide l37Cs in fruitbodies of Basidimycetes. Health Phys. 34:713-715. Hasholt, B. and D.E. Walling. 1992. Use of caesium-137 to investigate sediment source sedimend san t deliver smala n yi l glacierized mountain drainage basi Eastern ni n Greenland. IAHS Publ 209:87-100. .No . Hatton, R.S., R.D. DeLaune d W.Han , . Patric . 1983Jr k . Sedimentation, accretion, and subsidence in marshes of Barataria Basin, Louisiana. Limnol. Oceanogr. 28:494-502. Hawks, P.H., J.C. Ritchie, and J.R. McHenry. 1974. Measuring recent valley sedimentation rates using fallout cesium-137. Geol. Soc. Am. Abstracts with Program 6:363. Haworth, E.Y. 1976. The changes in the composition of diatoms assemblage ssurface founth n di e sediment Blelhaf so m Tarn ni the English Lake District during 1973. Ann. Bot. 40:1195-1205. Haworth, E.Y. 1980. Comparison of continuous phytoplankton records wite diatoth h m stratigraph recenn i y t sediment Blelhaf so m Tarn. Limnol. Oceanogr. 25:1093-1103.

Haworth, E.Y. 1984. Stratigraphie change algan si l remains (diatoms and chrysophytes recenn )i t sediment Blelhaf so m Tarn, English Lake District 165-190. ,pp E.Y: .Jn . Hawort J.W.Gd an h . Lund (eds.}, Lake sedimen d environmentaan t l history, Univ. Minnesota Press, Minneapolis, MN. Health and Safety Laboratory Fallout Program. 1972. HASL-258, A-40- 41, A-93-94, Health and Safety Laboratory, New York. Heathwaite, A.L. 1993. Catchment controe recenth n o tl sediment histor Slaptof yo n Ley, South-west England . 241-259,pp ' m .I D.S.G. Thoma R.Jd san . Allison (eds.}. Landscape sensitivity, John Wiley and Sons, Chichester, UK. Hebel, S.J d D.C.an . Wilkin. 1982. Agricultural land management strategie r sedimenfo s t reduction. Landscape Architecture 1982:91-95. Heijnis, H., G.W. Berger, and D. Eisma. 1987. Accumulation rates of estuarine sediment e Dollarth n i sd Area: compariso 2IOf no Pb and pollen influx methods. Res a NethSe .. .21:295-301J . Heit, M. and K. Miller. 1987. Cesium-137 sediment depth profiles and inventories in Adirondack lake sediments. Biochemistry 3:243-265.

155 Heit, M-, K.M. Miller, P. Krey, D. Bogen, and H. Freely. 1984. Other radionuclides: plutonium with some comments about l37Cs chronologies in freshwater sediments. Workshop on paleolimnological studies of the history and effects of acidic precipitation, Rockland 34-77. pp . .,ME Heit, M., Y.L. Tan, C.S. Klusek, and J.C. Burke. 1981. Anthropogenic trace element d polycyclian s c aromatic hydrocarbonn i s sediment cores from two lakes in the Adirondack acid lake region. Water Air Soil Pollut. 15:441-464. Heit, M., Y.L Tan, C.S. Klusek, H.L. Volchok, and J.C. Burke. 1980. The origin and deposition history of trace elements and polynuclear aromatic hydrocarbon remoto tw n si e e laketh n si Adirondack acid rain region. EML-381 . 1-7pp , o 1-127t 5 . Environmental Measurements Laboratory Yorkw ,Ne . Heit , Y.L,M. . Tan, K.M. Miller . QuanciJ , Marinetti. C , . S d ,an Silvestri. 1986. The sediment chronology and polycyclic aromatic hydrocarbon concentration fluxed san Cayugn si a Lake, N.Y., EML-451. Environmental Measurement Laboratory Yorkw ,Ne , 53pp. Heiton, J.C., A.B. Muller, and A. Bayer. 1985, Contamination of surface-water bodies after reactor accident erosioe th y sb f no atmospherically deposited radionuclides. Health Phys. 48:757- 771. Hermanson, M.H. 1993. Historical accumulation of atmospherically derived pollutant trace Arctimetale th measures n a csi n i d dated sediment cores. Wat. Sei. Tech. 28:33-41.

Hermanson, M.H. 1991. Chronolog sourced yan anthropogenif so c trace- metal n sedimeni s t cores from small shallow Arctic lakes. Environ. Sei. Tech. 25:2059-2064. Hermanson, M.H. 1990. 137210d CPan sb chronolog f sedimento y s from small, shallow Arctic lakes. Geochim. Cosmochim. Acta 54:1443- . 1451. Hermanson, M.H. and E.R. Christen. 1991, Recent sedimentation in Lake Michigan. J. Great Lakes Res. 17:33-50. Hermanson, M.H., E.R. Christen, D.J. Buser, and L.M. Chen. 1991. Polychlornated bipheny daten i l d sediments cores from Green Bay and Lake Michigan. J. Great Lakes Res. 17:94-108. Hesslein, R. H. 1987. Whole-lake metal radiotracer movement in fertilized lake basins. Can. J. Fish. Aquat. Sei. 44:74-82. Hesslein, R.H., W.S. Broecker, and D.W. Schindler. 1980. Fates of metal radiotracers added to a whole lake: sediment-water interactions. Can. J. Fish. Aquat. Sei. 37:378-386. Hetherington, J.A D.Fd .an . Jefferies. 1974 e distributioTh . f o n some fission product radionuclides in sea and estuarine sediments. Neth. J. Sea Res. 8:319-338. Hien, P.Z., N.T. Binh, T.Y Bac.T V N.Td ,an . Ngo. 1994. Variations of caesium isotope concentration falloud an r Dalatt ai ta n si , South Vietnam, 1986-91 Environ. .J . Radioact. 22:55-62. Higgit, D.L. 1991. Soil erosion and soil problems. Prog. Phys. Geol. 15:91-100. Higgitt, D.L. . Froehlichw , D.Ed an , . Walling. 1992. Applications and limitation f Chernobyo s l radiocaesium measurementa n i s Carpathian erosion investigation, Poland. Land Degradation and Rehabilitation 3:15-26.

156 Higgitt, D.L., J.S. Rowan, and D.E. Walling. 1993. Catchment-scale deposition and redistribution of Chernobyl radiocaesium in upland Britain. Environ. Internat. 19:155-166. Hilton . 1985J , .A conceptiona l framewor r predictinfo k e th g occurrence of sediment focusing and sediment redistribution in small lakes. Limnol. Oceanogr. 30:1131-1143. Hilton, J., R.s. Cambray, and N. Green. 1992. Chemical fractionation of radioactive caesium in airborne particles containing bomb fallout, Chernobyl fallou atmospherid tan c materials froe mth Stellafield site Environ. .J . Radioact. 15:103-111. Hilton, J., L. Davison, J. Hamiltontaylor, M. Kelly, F.R. Livens, E. Rigg, and D.L. Singleton. 1994. Similarities in the behaviour of Chernobyl derived Ru-103, Ru-106 and Cs-137 in two freshwater lakes. Aquat. Sei. 56:133-144. Hilton, J., J.P. Lishraan, and P.V. Alien. 1986. The dominant processes of sediment distribution and focusing in a small, eutrophic, monoraictic lake. Limnol. Oceanogr. 31:125-133.

Hilton , F.RJ. , . Livens . SpezzanoP , d D.R.Pan , . Leonard. 1993. Retention of radioactive caesium by different soils in the catchmen smala f to l lake. Sei. Total Environ. 129:253-266. Hilton, J. and P. Spezzano. 1994. An investigation of possible processes of radiocaesium release from organic upland soils to water bodies. Water Res. 28:975-983. Hirschberg, D.J. and J.R. Schubel. 1979. Recent geochemical history of flood deposits in the northern Chesapeake Bay. Estuar. Coast. Marine Sei. 9:771-784. Hohenemser Deicher. M , ,C. Ernst. ,A Hofsäss. ,H Linder. ,G . E d ,an Recknagel. 1986. Chernobyl: an early report. Environ. 28:6-43. Hongve , I.A,D. . Blaka J.Ed ran . Brittain. 1994. Radiocesiue th n i m sediment 0vrf so e Heimdalsvatn Norweiga,a n subalpine lake. Abstracts of the ASLO & PSA 1994 Joint Annual Meeting, Miami, FL. p-a35. Horrill, . ClintG A.D d .an . 1994. Caesium cyclin n heathei g r moorlands ecosystems, pp. 395-416. Jn: S.M. Ross (éd.), Toxics in Plant-Soil Systems, John Wiley, Chichester. ,UK Horrill ,Howard. A.DM d .an . 1991. Chernobyl fallou thren ti e areas of upland pastur wesn i e t Cumbria . RadiolJ . . Prot. 11:249- 257. Hotzl, H., G. Rosner, and R. Winkler. 1992. Sources of present Chernobyl-derived caesium concentrations in surface air and deposition samples. Sei. Total Environ. 119:231-242. Howard, B.J., N.A. Beresford F.Rd ,an . Livens. 1990 overvie.n A f wo caesium in the semi-natural ecosystem of an upland sheep farm, In: G. Desmet, P. Nossimbeni, and M. Belli (eds.), Transfer of radionuclides in natural and seminatural ecosystems, Elsevier, Amsterdam. Hubbard, J.E. and W.D. Striffler. 1973. Cesium 137 in a mountain channel. Water Resour. Res. 9:1440-1442. Hunt, G.J d P.J.an . Kershaw. 1990. Remobilizatio f artificiao n l radionuclides from the sediment of the Irish Sea. J. Radiol. Prot. 10:147-151. Hutchinson, S.M. 1994. Distribution of l37Cs in saltmarsh sediment in the Dee Estuary, NW England. Marine Pollut. Bull. 28:262-265.

157 Hutchinson, S.M. and D. Prandle. 1994. Siltation in salt marsh of e EstuarDe e yth derived from l37Cs analysi f shalloso w cores. Estuar. Coast. Shelf Sei. 38:471-478. Hutchinson-Benson, E., J. Svoboda, and H.W. Taylor. 1985. The latitudinal inventory of l37Cs in vegetation and topsoil in Northern Canada, 1980. Can Bot. J . 63:784-791. Inbar . 1982,M . Measuremen fluviaf to l sediment transport compared with lacustrine sedimentation ratese Rive th e flo th :f ro w Jordan into Lake Kinneret. Hydrological Sei 4:439-449. .J .

Inbar, M. 1992. Rates of fluvial erosion in basins with a Mediterranean climate. Catena 19:393-409. Irlweck, K. 1985. Depth distribution of '"cesium, "'strontium and lea sedimentn i d Lakf so e Mondsee, Austria Radiât. .J . Nucl.

-Chem2lo . Lett. 93:115-124. Irlweck d D.Lan . . DanielopolK , . 1985. Caesium-13 d lead-21an 7 0 dating of recent sediment from Mondsee (Austria). Hydrobiologia 128:175-185. Irlweck, K., B. Khademi, E. Henrich, and R. Kronraff. 1993. Pu-239(240), Pu-238, Sr-90, Ru-10 Cs-13d 3an 7 concentrations n surfacn Austrii o dispersioi t r e ai du ea f Chernobyo n l releases over Europe. J. Environ. Radioact. 20:133-148. Jaakkola, T., K. Tolonen, P. Huttunen, and S. Leskinen. 1983. The use of l37Cs and 239-2*>pu for dating lake sediments. Hydrobiologia 103:15-19. Jasinski J.Ad an .. RobbinsT , . 1988, Radiotracer Polisn i s h lake sediments. EOS Trans. 69:1119. Jaworowski . 1966Z , . Tempora d geographicaan l l distributiof o n radium D (lead 210). Nat. 212:886-889. Jefferies, D.F d A.K.an . Steele. 1989. Observe d predictean d d concentration f caesium-13so e seawate e th Iris th n i 7f h o r Sea. J. Environ. Radioact. 10:173-189. Jefferies, D.F., A.K. Steele, and A. Preston. 1973. Distribution of caesium-13 n Britisi 7 h coastal water. Mar. Pollut. Bull. 4:118-122. Jefferies, D.F., A.K. Steele, and A. Preston. 1982. Further studies on the distribution of l37Cs in British coastal water I. Irish Sea Deep-Sea Res. 29:713-738. Jenne, E.A. and J.S. Wahlberg. 1968. Role of certain stream-sediment components in radioion sorption. U.S. Geological Survey, Paper 433-FWashington, pp 6 ,1 . ,DC Johanson, K.J., R. Bergstrom, O. Eriksson, and A. Erixon. 1994. Activity concentrations of Cs-137 in moose and their forage plants in Mid-Sweden. J. Environ. Radioact. 22:251-267. Johnson, T.C. 1984. Sedimentation in large lakes. Ann. Rev. Earth Planet. Sei. 12:179-204. Johnston, C.A. 1992. Sediment and nutrient retention by freshwater wetlan effect- d surfacf so e water quality Environ. R . Cr . . Con. 21:491-565. Johnston, C.A., G.D. Bubenzer, G.B. Lee, F.W. Madison, and J.R. McHenry. 1984. Nutrient trapping by sediment deposited in a seasonally flooded lakeside wetland Environ. .J . Qual. 13:283- 290.

158 Johnston, S.E. 1981 .A compariso datinf no g method n laminatei s d lake sediments in Maine. M.S. Thesis, Univ. Maine, Orno, ME.

Johnston, S.E., S.A. Norton, C.T. Hess, R.B. Davis, and R.S. Anderson. 1982. Chronolog atmospherif yo c depositio acif no d and metals in New England based on the record in lake sediment, pp. 177-187. In: L.H. Keith (ed.)» Energy and environmental chemistry. Vol. 2. Acid rain, Ann Arbor Science Publishers, Ann Arbor, MI. Jones, D.G., J.M. Miller P.Dd ,an . Roberts. 1984 distributioe .Th n surfacCn si f o e intertidal sediments froSolwae mth y Firth.

137 Marine Pollut. Bull. 15:187-194. R.Gd Jonesan .. CastleF , . 1987. Radioactivity monitorine th f o g water cycle following the Chernobyl accident.

Kozhevnikova, T.L., N.N. Mishenkov, L.N. Martyushova, and D.A. Krivolutskii. 1993. Accumulatio Sr-9f no Cs-13 d 0an fruiy 7b t bodies of mushrooms. Russian J. Ecol. 24:391-394. Kramer, K.J.M- Misdrop. ,R Berger. ,Duyts. C R d .,an 1991. Maximum pollutant concentration at the wrong depth - a misleading pollutant history in a sediment core. Mar. Chem. 36:183-198.

159 Krey, P.W., E.P. Hardy, and M. Heit. 1980. Nevada test site fallout in the area of Enterprise, Utah. EML-372, 30 pp. Environmental Monitoring Laboratory, New York. Krey, P.W., M. Heit, and K. Miller. 1990. Radioactive fallout reconstruction from contemporary measurement of reservoir sediments. Health Phys. 59:541-554. Krezoski, J.R., S.C. Mozley, and J.A. Robbins. 1978. Influence of benthic macroinvertebrate mixinn so profundaf go l sedimentn si southeastern Lake Huron. Limnol. Oceanogr. 23:1011-1016. Krezoski, J.R d J.Aan . . Robbins. 1985. Vertical distributiof o n feedin d particle-selectivan g e transpor f 137o n tlakCi s e sedimen y lumbriculib t d Oliqochaetes . GeophysJ . . Res. 90:11999-12006. Krezoski, J.R., J.A. Robbins, and D.S. White. 1984. Dual radiotracer measuremen f o zoobenthos-mediatet d solut d particlan e e transpor n i freshwatet r sediments . J Geophys. . Res. 89:7937-7947. Krishnaswami, S., L.K., Benninger, R.C. Aller, and K.L. Von Damm. 1980. Atmospherically-derived radionuclide s tracera s f o s sediment mixin accumulatiod gan near-shorn ni e marin lakd ean e sediments: evidence from 7Be, 210239>2d Pan *b> Pu. Earth Planet. Sei. Lett. 47:307-318. Krishnaswami Lal. D d .an 1978. ,S . Radionuclide limnochronology. ,pp 153-177. In'. . LermaA n (ed.), Lakes chemistry, geologyd ,an physics, Springer-Verlag Yorkw ,Ne . Krishnaswamy, L.K. . LalD , , J.M. Martin. MaybeckM d an , . 1971. Geochronology of lake sediments. Earth Planet. Sei. Lett. 11:407-414. Krivolutskii, O.A., V.L. Usachev, I.A. Ryabtsev O.Vd ,an . Tarasov. 1989. Global sediment radionuclide migration in trophic chains of arid zone biogeocenoeses. Zh. Obshch Biol. 50:595-605. (Russian) Krom, M.D. ,Kaufman. A Hornung. H d ,an . 1994. Industrial mercurn i y combination with natural Pb-210 as time-dependent tracers of sedimentatio d mercuran n y removal from Haifa Bay, Israel. Estuar. Coastal Shelf Sei. 38:625-642. Ku, W.C. 1973. Aquatic sediments . WateJ . r Poll. Control Fed. 45:1301-1310. E.Fd Kudoan .. ,A Gloya. 1971. Transpor I Interactio I lî7f o tC- s n wit sedimentsd hbe . Water Res. 5:71-79.

Kodaira, K. , M. Kato, and M. Ishikawa. 1973. Radiochemical analysis 2IOf o Pbwels ,a distributios la 2lf °Pbno , ""Sr I37d soin Can ,si l profiles. Radioisotopes, Tokyo 22:331-336. d J.Ran Koh .. M , McHenry. 1987. Determining sediment rates using cesium-137 fallout at Larto Lake. J. Korean Soc. Soil Sei. Fertility 15:207-212. Koide K.W, ,M. . Bruland E.Dd ,an . Goldberg. 1973. Th-238/Th-23d 2an Pb-210 geochronologie marinn si lakd ean e sediments. Geochim. Cosmochia. Acta 37:1171-1187. Koide, M., A. Soutar, and E.D. Goldberg. 1972. Marine geochronology with 210Pb. Earth Planet. Sei. Lett. 14:442-446.

Komarneni . 1978S , . Cesium sorptio d desorptioan n n behaviof o r kaolinites. Soil Sei. Soc. Am. J, 42:531-532.

160 Konitzer, K. 1992. Sedimentroerelsers betydekse foer foerdelning och tillgaenglighe v n Cs-13a mellansvense t I 7 k skogssjoe (Redistribution of Cs-137 in sediment caused by sediment movements), Limnilogiska Institutionen Repor NEI-SE-139. tNo , 24pp. Uppsala, Sweden. Konoplev, A.V., L.P. Kopylova, Ts.I. Bobovnikova, A.A. Bulgakov, and A.A. Siverina. 1992. 90Sr and 137Cs distribution in the bottom sediment-water reservoir system in the Chernobyl close-in zone. Soviet Meteorology and Hydrology 1:27-33. Konshin, O.V. 1992. Transfe l37f ro Cs from soi graso lt analysis- s of possible sources of uncertainty. Health Phys. 63:307-315. Konshin, O.V. 1992. Applicabilit e convection-diffusioth f o y n mechanism for modeling migration of I37Cs and *°Sr in soil. Health Phys. 63:219-300. Konshin, O.V. 1992. Mathematical model of I37Cs migration in soil: analysis of observations following the Chernobyl accident. Health Phys. 63:301-306. Konshin, O.V. 1992. Transfer of !37Cs from soil to grass - analysis of possible source uncertaintyf so . Health Phys. 63:307-315. Korhonen, R. 1990. Modelling transfer of Cs-137 fallout in a large Finnish water course. Health Phys. 59:443-454. Korobova, E.M. and V.G. Linnik. 1994. Geochemical landscape strategy in monitoring the areas contaminated by the Chernobyl radionuclides. Landscap Urbad ean n Planning 27:91-96. Korschgen, C.E., G.A. Jackson, L.F. Muessig D.Cd .an , Southworth. 1987. Sedimentation on Lake Onalaska, Navigation Pool 7, Upper Mississippi River, since impoundment. Water Resour. Res. 23:221-226. Kotwicki, V. and P. Isdale. 1991. Hydrology of Lake Eyre, Australia Ninl E o- Link. Paleo. Pollut. 84:87-98.

Kearney, M.S., J.C. Stevenson, and L.G. Ward. 1994. Spatial and temporal changes in marsh vertical accretion rates at Monie Bay: Implications for sea-level rise. J. Coastal Res. 10:1010-1020. Kedhi 1989. ,K . Radiotracer stud depositiof yo n cause y suspendedb d sediments of river Seman. J. Radioanal. Nucl. Chem. Lett. 135:395-402. Keilty, T.J., D.S. White d P.Fan , . Landrum. 1988. Sublethal responses to endrin in sediment by Stylodrilus heringianus (Lumbriculidae s measurea ) a "'cesiu y b d m marker layer technique. Aquat. Toxicology 13:251—270. Kemp, A.L.W., T.W. Anderson, R.L. ThomasMudrochova. A d ,an . 1974. Sedimentation rates and recent sediment history of Lakes Ontario, Eri Hurond ean Sedimentar. .J y Petrology 44:207-218. Kemp, A.L.W., R.L. Thomas, C.I. Deli, and J.M. Jaquel. 1976. Cultural impact on geochemistry of sediment in Lake Erie. J. Fish. Res. 33:440-462. Kirihara, S., R. Nakamura, M. Nakahara, M. Notoya, and Y. Aruga. 1993. Translocation of Sr-85, Cs-137, Co-57, and Zn-65 through Stoloniferous haptera betwee e thallth nf o Ecklonii a stolonifera Okamura (Laminariales, Phaeophyta) Nippon Suisan Gakkaishi. Bull. Japanese Soc. Scientific Fisheries 59:589-592. Kirk, . StauntonG.J.DS d an . . n predictinO 1989. e fatth f go e radioactive caesium in soil beneath grassland. J. Soil Sei. 40:71-84. 161 Kiss, J.J., E. de Jong, and L.W. Martz. 1988. The distribution of fallout cesium-137 in southern Saskatchewan, Canada. J. Environ. Qual. 17:445-452. Kiss, J.J., E. de Jong, and H.P.W. Rostand. 1986. An assessment of soil erosion in West-central Saskatchewan using cesium-137. Can. J. Soil Sei. 66:591-600. Klechkovdkii, V.M., G.G. Polikarpov, and R.M. Aleksakhi. 1973. Behavio strontium-9f ro cesium-13d 0an soiln 7i , Chaptep p . r4 78-102. In: Radioecology, Wiley, New York.

Kline, J.R., J.A. Colo S.Sd nan . Brar. 1973. Distributio 137f n Co i s soils and vegetation on the island of Puerto Rico. Health Phys. 24:469-475. Klobe, W.D. and R.G. Gast. 1970. Conditions affecting cesium fixatio d sodiuan n m entrapmen n i hydrobiotitt d an e vermiculite. Soil Soi. Soc Proc. .Am , 34:746-750. Klusek, C.S. 1987. Strontium-90 in food and bone from fallout. J. Environ. Qual. 16:195-199. Knatko, V.A., V.V. Gurkov, V.D. Asimova, E.B. Shpakovskaya, and E.A. Shimanovich. 1994. Soil milk transfe Cs-13 f arern o a f ao n 7i Byelarus afte Chernobye rth l accident Environ. .J . Radioact. 22:269-278.

Juzdan . 1988Z , . Worldwide depositio f *>So nr through 1985. USDOE Report, EML-515, Environmental Monitoring Laboratoryw Ne , York. Kachanoski, R.G. 1987. Compariso measuref no d soil 137-cesium losses and erosion rates. Can Soi. .J l Sei. 67:199-203. Kachanoski, R.G. 1993. Estimating soil loss from change n soii s l cesium-137. Can Soi. J l Sei. 73:515-526. Kachanoski, R.G. and E. de Jong. 1984. Predicting the temporal relationship between cesium-13 erosiod 7an n rate Environ. .J . Qual. 13:301-304. Kacieszczenko Banasik. Z d an . ,J 1981 .effecn A bioturbatiof to n no e result I37e th Cth s f datinso g technique user lacustrinfo d e sediments. Ekologia Polska 29:615-623. Kada, J and M. Heit. 1992. The inventories of anthropogenic lead, zincr arsenic, cadmium and radionuclides cesium-137 and excess lead-210 in lake sediment of the Adirondack region, USA. Hydrobiologia 246:231-241. Kada, J., M. Heit, and K.M. Miller. 1994. Chronology of anthropogenic trace element inpu o t fout r Utah lakes reconstructed using sediment cores. Water Air Soil Pollut. 75:353-369. Kadlec, R.H. and J.A. Robbins. 1984. Sedimentation and sediment accretion in Michigan coastal wetlands (U.S.A.). Chem. Geol. 44:119-150. Kaminski . 1991S , . Radionuklid m Tschernobyl-Falloude s au e m i t Bodensee. GWF-Wasser Abwasser 132:671-674. Kamiyama Okuda. Koyama. S M d , ,an K. . 1982. Vertical distribution s accumulatiooit f l37d Can s n rat n laki e e sediment. Jap. .J Limnol. 43:35-38. Kansanen, P.H. 1985. Assessment of pollution history from recent sedimen Lakn ti e Vavajavesi, southern Finlan . ChangeII d n si e Chironomidaeth , Chaoborida d Ceratopogonidaan e e (Diptera) fauna. Ann. Zool. Fennici 22:57-90.

162 Kansanen, P.H. and T. Jaakkola. 1985. Assessment of pollution history from recent sedimen n Laki t e Vavajavesi, southern Finlan Selectio. dI representativf no e profiles, their dating and chemostratigraphy. Ann. Zool. Fennici 22:13-55. Kansanen, P.H. and J. Seppala. 1992. Interpretation of mixed sediment profile y meana sediment-mixinb s f o s g moded an l radioactive fallout. Hydrobiologia 243:371-379. Kasimovsky, A.A. 1993. Analytical solution for the model of soil radionuclide migration with fixation-leaching reaction. Ecol. Modell. 66:217-229. Kawabata, T. 1967. Studies on the sorption and release of radionuclide rivey sb r sediments Radiât. .J . Res. 8:20-3O.

Kulander, L. and L. Strömguist. 1989. Exploring the use of top-soil i;>7Cs content as indicator of sediment transfer rates in a small Lesotho catchment Geomorph. Z . . N.F. 33:455-456. Labadz, J.C., T.P. Burt A.W.Rd ,an . Potter. 1991. Sediment yield dan delivery in the Blanket Peat Moorelands of the southern Pennies. Earth Surf. Proc. Landforms 16:255-271. Laflen, J.M. , W.J. Elliot, J.R. Simanton, C.S. Holzhey, and K.D. Kohl. 1991. WEPP Soil erodibility experimen rangelanr tfo d dan cropland soil. J. Soil Water Conserv. 46:39-449. Laflen, J.M., L.J. Lane, and G.R. Foster. 1991. WEPP A new generatio f erosioo n n prediction technology . SoiJ . l Water Conserv. 46:34-38. Lal, D. 1991. Cosmic-ray labeling of erosion surfaces, insitu nuclide production rates and erosion models. Earth Planet. Sei. Lett. 104:424-439. Lal, D., E. Barg, A.J.T. Jull, M. Pavich, J. Southon, M.W. Caffee, d R.Can . Finkel. 1993 Cosmogeni- . c nuclear methodr fo s determining soil erosion and formations rates. Im Proceeding international symposium on applications of isotope techniques n studyini g pasd currenan t t environmental changee th n i s hydrosphere and atmosphere. (In Press), International Atomic Energy Agency, Vienna, Austria. Pavich. . M BargE d , Lalan ,.D. , 1991. Developmen f cosmogenio t c nuclear methodstude th soif o yr lsfo erosio d formationan n rates. Current Sei. 61:636-640. Lal, D., V.M. Nijampurkar, and S. Rama. 1970. Silicon-32. Proceeding Hydrology 1970 . 847-868pp , , International Atomic Energy Agency, Vienna, Austria. Lambert, C.P. and D.E. Walling. 1987. Floodplain sedimentation: a preliminary investigatio f contemporaro n y deposition within the lower reaches of the River Culm, Devon, UK. Geografiska Annaler 69A: 393-404. Lance, J.C., S.C. Mclntyre, D.G. DeCoursey, P.G. Sharpe, S.S. Rousseva d B.Lan , . Campbell. 1986. Using cesium-13o t 7 estimate erosion rate rangelandn so 79-89. ,pp m Erosio.I n control: protectin futurer gou , International Erosion Control Association. Lance, J.C., S.C. Mclntyre, R.R. Lowrance, B.L. Campbell, and R.L. Miller. 1986. Cesium-137 measures erosion rate sedimend san t movement. 4th Federal Interagency Sedimentation Conference, 4-9o t . pp1 .4- Lance, J.C., S.C. Mclntyre, J.W. Naney S.Sd an , . Rousseva. 1986. Measuring sediment movement at low erosion rates using cesium- 137. Soil Sei. Soc. Am. J. 50:1303-1309.

163 Larson, R.J. 1985. Worldwide fallou Sr-9f o t 0 through 1983. USDOE Rep. EML-444, Environmental Monitoring Laboratory, New York.

Lehman, J.T. 1975. Reconstructin rate f accumulatiogth eo f lako n e sediment effece th : f sedimeno t t focusing. Quat. Res. 5:541- 550. Leland, H.V., S.N. Leoma, J.F. Elder D.Jd ,an . Wilkes. 1978. Heavy metal d relatean s d trace element Review- s . WateJ . r Poll. Control Fed. 50:1469-1514. Lemmin D.Md an .. , U Imboden. 1987. Dynamic bottof so m currenta n si small lake. Limnol. Oceanogr. 32:62-75. Lentsch, J.W. 1974. The fate of gamma-emitting radionuclides released int Hudsoe oth n River estuarevaluation a d an y f no their environmental significance. Ph.D. Thesis w YorNe ,k Univ., New York. Leonard, E.M. 1986. Varve studies at Hector Lake, Alberta, Canada, e relationshith and p between glacial activitd an y sedimentation. Quat. Res. 25:199-214. Lerman, A. 1979. Geochemical processes: water and sediment. Wiley, New York. Lerman T.Ad an .. ,A Lietzke. 1975. Uptak migratiod ean tracerf no s in lake sediment. Limnol. Oceanogr. 20:497-510. Lewin, J. 1977. Floodplain geomorphology. Prog. Phys. Geog. 1:408-437. Li, Y. H., L. Burkhardt, M. Bucholtz, P. O'Hara, and P.H. Santschi. 1984. Partitio radiotracerf no s between suspended particles watera anse d . Geochia. Cosmochim. Acta 48:2011-2020. . 1992Yu . .Y d Investigationan . P , Li f naturao s d artificiaan l l radioactive isotope seawaten si sedimentd r an Yelloe th n i sw d adjacenSean a t southeast area. Chin . OceanolJ . . Limnol. 10:325-330. Lieser . ,Steinkopff Th K.H d an . . 1989. Chemistr f radioactivo y e cesium in the hydrosphere and in the geosphere. Radiochem. Acta. 46:39-47. Linder, G. , M. Becker, R. Eckmann, P. Frenzel, J. Kleiner, D. Petermann-Seyboldt, W. Pfeiffer, U. Wahl, and E. Recknagel. 1990. Biological transfer and sedimentation of Chernobyl radionuclide Lakn si e Constance 265-287. ,pp m M.M.I . Tilzer anSerruy. C d a (eds.), Large lakes: ecological structurd ean function, Springer-Verlag, Berlin. Linder. PfeifferW , G. ,. Wahl U , . KleinerJ , , H.H. Stabel. P , Frenzel, J.A. Robbins, F. Giovanoli, A. Lenhard, and E. Recknagel. 1989. Sedimentation of long-lived radionuclides in Lake Constance . 449-452pp , J.P: In . . Vernet (ed.), Heavy metalenvironmente th n i s ConsultantsP ,CE , Edinburgh. ,UK Linsalata H.J, ,P. . Simpson, C.R. Olsen Cohen. ,N R.Md ,.an Trier. 1985. Plutonium and radiocaesium in the water column of the Hudson River estuary. Environ. Geol. Water Sei. 7:193-204.

Livens, F.R M.Sd .an . Baxter. 1988a. Particle siz radionuclidd ean e level somn i s e west Cumbrian soils. Sei. Total Environ. 70:1- 17. Livens, F.R. and M.S. Baxter. 1988b. Chemical associations of artificial radionuclide n Cumbriar s n soils . EnvironJ . . Radioact. 9:75-86.

164 Livens, F.R. . FowlerD , d A.Dan , . Horrilly dr .d 1992an t We . depositio 1-131f no , Cs-13 Cs-13d uplann a 4an t 7a d sitn i e Northern England Environ. .J . Radioact. 16:243-254. Livens, F.R., A.D. Horrill, and D.L. Singleton. 1991. Distribution of radiocaesiu n soii m l plant system f uplano s d areaf o s Europe. Health Phys. 60:539-545. Livens, F.R d P.Jan . . Loveland. 1988 e influencTh . f soio e l propertie e environmentath n o s l mobilit f caesiuo y n i m Cumbria. SoiManagee lUs . 4:69-75. Livens, F.R. and D. Rimmer. 1988. Physico-chemical controls on artificial radionuclides in soil. Soil Ose Manage, 4:63-69. Livingston . 198.4D ,e preservatioTh . f algao n l remain n receni s t lake sediment 191-202. ,pp E.Y: .In . Hawort J.W.Gd han . Lund (eds.), ~Lake sedimen d environmentaan t l history, Univ. Minnesota Press, Minneapolis, MN. Livingston, H.D, and T. Bowen. 1979. Pu and l37Cs in coastal sediments. Earth Planet. Sei. Lett. 43:29-45.

Livingstone R.Sd an . . Cambry,D . 1978. Confirmatio 'f 37no C s dating by algal stratigraph Rosthernn i y e Mere. Nat. 276:259-261. Llaurado . VidaiM , . RauretG ,M. , . RocaC , . Fons J ,d V.R an , . Vallejo. 1994. Radiocesium behaviour in Mediterranean conditions. J. Environ. Radioact. 23:81-100. Lomenick, T.F. and T. Tamura. 1965. Naturally occurring fixation of cesium-137 on sediments of lacustrine origin. Soil Sei. Soc. A«. Proc. 27:383-386. Longmore, M.E. 1982. The caesium-137 dating technique and associated application n Australiai s A review— . 310-321. pp ,W : In . Ambrose and P. Duerden (eds.). Archaeometry: an Australasian perspective, Australian National Univ. Press, Canberra, Australia. Longmore, M.E., J.G. Luly d B.Man , . O'Leary. 1986. Cesium-137 redistribution in the sediment of the Playa, Lake Tyrrell, Northwestern Victoria. II. Patterns of cesium-137 and pollen redistribution. Palaeogeography, Palaeoclimatology, Palaeoecology 54:197-218. Longmore, M.E., B.M. O'Leary, and C.W. Rose. 1983. Caesium-137 in the sediments of a partial-meromictic lake on Great Sandy Island (Fraser Island), Queensland, Australia. Hydrobiologia 103:21-27.

Longmore, M.E., B.M. O'Leary, C.W. Rose A.Ld ,an . Chandica. 1983. Mapping erosion and accumulation with the fallout isotope caesium-137. Aust. J. Soil Res. 21:373-385. Longmore, M.E. Torgersen. ,T , B.M. O'Leary J.Gd an , . Luly. 1986. Cesium-137 redistributio sedimene Playae th th n i nf ,to Lake Tyrrell, Northwestern Victoria. I. Stratigraphy and Cesium-137 e th «nobilitUppe rn i ysediments . Palaeogeography, Palaeoclimatology, Palaeoecology 54:181-195. Lönsj . 1989,H . Depth distributio radiocesiuf no agriculturaln i m ' soils in Chernobyl fallout areas of Sweden in 1987-1988, pp. 134-142 M.H: .In . Gerzabek (ed.), Proceeding e XlXtth f hso ESNA Conference, Austrian Research Center, Seibersdorf, Report No. 4489. Loughran, R.J. 1989. The measurement of soil erosion. Prog. Phys. Geog. 13:216-233.

165 Loughran, R.J. and B.L. Campbell. 1983. The .determination of sedimentation dept caesium-137y hb . Search 14:157-158. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1980. Sediment dynamic Malunn si a Creek catchmen Pokolbint ta , N.S.W. Papers of the Newcastle (16th) Conference of the Institute of Australian Geographers, pp. 245-254. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1981. Sediment erosion, storag transpord ean smala n ti l steep drainage basin at Pokolbin, NSW, Australia. IAHS Publ. No. 132:252-268. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1982. The identification and quantification of sediment source using l37Cs. IAHS Publ. Mo. 137:361-369.

Loughran, R.J., B.L. Campbell d G.Lan , . Elliott. 1983e Th . determination of sedimentation depth by cesium-137. Search 14:5-6. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1986a. A nuclear technique measures soil erosion. Nucl. Spectrum 2:2-4. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1986b. Sediment dynamic a partiall n i s y cultivated catchmen w SoutNe n hi t Wales, Australia. J. Hydrol. 83:282-297. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1986c. The use of tracer caesium-137 for studying sediment movement in drainage basins . 151-160 . pp ,FrankelE : In . , J.B. Keene d A.Ean , . Waltho (eds.), Recent sediment Eastern si n Australi Marina- e through terrestrial. Geological Society of Australia, Univ. Sidney, Sidney, Australia. Loughran, R.J., B.L. Campbell, and G.L. Elliott. 1988. Determination of erosion and accretion rates using caesium-137, pp. 87-103. In: R.F. Warner (ed.), Fluvial geomorphology of Australia, Academic Press, Sidney, Australia.

Loughran, R.J., B.L. Campbell d G.Lan , . Elliott. 1990e Th . calculatio t soine l f o nlos s using cesium-137 . 119-126,pp . In: J. Broadman, I.D.I. Foster, and J.A. Dearing (eds.). Soil erosion on agricultural land, Wiley, New York. Loughran, R.J., B.L. Campbell, G.L. Elliott Cummings. ,D D.Jd ,an . Shelly. 1989. A cesium-137 sediment hillslope model with test from south-eastern Australia Geomorph. .2 . N.F. 33:235-250. Loughran, R.J., B.L. Campbell, G.L. Elliott D.Jd ,an . Shelly. 1990. Determinatio e rat th f sheeo e f o nt erosio grazinn o n g land' using caesium-137. Appl. Geography 10:125-133. Loughran, R.J., B.L. Campbell, A.T. Pilgrim, and A.J. Conacher. 1987. Caesium-13 n soili 7 n relatio i e snin th e o t nuni t landsurface model in a serai-arid environment of Western Australia . 398-406 pp ,Conache. A : ,In r (ed.), Readingn i s Australian Geography, Proceeding f -tho s e 21st Institutf o e Australian Geographer's Conference, Univ. Western Australia, Perth, Australia. Loughran, R.J., B.L. Campbell, D.J. Shelly G.Ld ,an . Elliott. 1992. Developin a sedimeng t budgea smal r lfo t drainage basin i n Australia. Hydrol. Processes 6:145-158. Loughran, R.J., B.L. Campbell, and D.E. Walling. 1987. Soil erosion and sedimentation indicate caesiuy b d m 137: Jackmoor Brooke catchment Devon, England. Catena 14:201—212.

166 Loughran, R.J., B.L. Campbell, D.E. Walling, and G.L. Elliott. 1985. Caesium redistribution and sediment movement in two catchments in England and Australia. • First international conference on geomorphology, Manchester. ,UK Loughran, R.J., G.L. Elliott, B.L. Campbell D.Jd ,an . Shelly. 1988. Estimation of soil erosion from caesium-137 measurements in a small cultivated catchment in Australia. J. Appl. Radiât. Isot. 39:1153-1157. Loughran, R.J., D.J. McFarlane, B.L. Campbell . SheppardR d an , . distributio1993e Th . caesium-13f no rangelann i 7 d soilt sa three sites in Western Australia. Rangeland J. 15:24-38. Low, K. and K. Edvardson. 1960. Content of caesium-137 and (zirconium + niobium)-95 in Swedish soils. Nat. 187:736-738. Lowrance, R., S. Mclntyre, and C. Lance. 1988. Erosion and deposition in a field/forest system estimated using cesium-137 activity. J. Soil Water Conserv. 43:195-199. Ludlam, S.D. 1984. Fayetteville Green Lake, New York, U.S.A. VII. Varve chronolog sedimend yan t focusing. Chem. Geol. 44:85-100. Lund, J.W.G. 1984. Winifred Tutin - a personal note, pp. 1-10. In: E.Y. Hawort d J.W.Gan h . Lund (eds.), Lake sedimend an t environmental history, Univ. Minnesota Press, Minneapolis, MN. Lynch, D.R C.Bd .an . Officer. 1984. Nonlinear parameters estimation for sediment cores. Chem. Geol. 44:203-225.

Lynch, J.C., J.R. Meriwether, B.A. McKee Vera-Herrera. ,F R.Rd ,an . Twilley. 1989. Recent accretion in mangrove ecosystems based 1372ln d °Pbo Can s . Estuar. 12:284-299. Lyons, W.B., P.B. Armstrong, and H.E. Gaudette. 1983. Trace metal concentrations and fluxes in Bermuda sediments. Marine Pollut. Bull. 14:65-68. Mackenzie, A.B., M.S. Baxter, I.G. McKinley, D.S. Swan, and W. Jack. 1979 e determinatioTh . !3xf o Csn , "7Cs, "Pba ,^R 22 *Rad an , concentrations in nearshore marine sediments and seawater. J. Radioanal. Chea. 48:29-47. Maguire , I.DS. , . Pulford, G.T. Cook A.Bd an , . Mackenzie. 1992. Caesium sorption-desorption in clay-humic acid systems. J. Soil Sei. 43:689-696. Mahara . 1993,Y . Storag migratiod ean fallouf no t strontium-9d 0an cesium-137 for over 40 years in surface soil of Nagasaki. J. Environ. Quai. 22î722-730. Mahara_y Y., A. Kudo, T. Kauri, D. Santry, and S. Miyahara. 1988. Mobiln reservoii u P e r sedimen f Nagasakio t , Japan. Health Phys. 54:107-111. Mahara, Y. and H. Matsuzuru. 1989. Mobile and immobile plutonium in a ground water environment. Water Res. 23:43-50. Mahara, Y. and S. Miyahara. 1984. Residual plutonium migration in soi Nagasakif lo Geophys. .J . Res. 89:7931-7936. Makhon'ko, K.P., T.I. Bobovnikova, A.S. Avramenko, A.V. Dibtseva, and A.A. Volokitin. 1975. Vertical distribution of Sr90 and Cslî7 in bottom deposits of lakes and rivers. Ekologiya 3:90- 93. Makhon'ko, K.P., F.A. Rabotnova, and A.A. Volokitin. 1990. Analysis of soil contamination by I37Cs in USSR in 1988. Atomnaya Energiya 68:262-264.

167 Mangini Christian. U , ,A. Barth, ,M . Schmitz,W d H.H,an . Stabel. 1990. Pathway d residencan s e tiroe f radiotracero s n Laki s e Constance, pp. 245-264. Im H.H. Tilzer and C. Serruya (eds.), Large lakes: ecological structure and function, Springer- Verlag Yorkw ,Ne . Mann, D.R. and S.A. Casso. 1984. In-situ chemisorption of radiocesium from seawater. Mar. Chem. 14:307-318. Martin, D.B. 1985. Accumulation of sediment, nutrients, and cesium-13 prairin 7i e pothole cultivaten si noncultivated dan d watersheds, pp. 274-275. In: Perspectives in nonpoint source pollution, USEPA, Washington, DC. Martin, D.B. and W. Hartman. 1987. The effect of cultivation on sediment compositio d depositioan n n prairii n e pothole wetlands. Wate Soir rAi l Pollut. 34:45-53. Martin 1985. ,J Pavie .Th n Crater lake 169-188. ,pp Strumm. W : .In , (ed.), Chemical processes in lakes, Wiley, New York.

Mitchell, J.K., G.D. Bubenzer, J.R. McHenry J.Cd ,an . Ritchie. 1980. Soil loss estimation from fallout cesium-137 measurements. ,pp 393-401. In: H. DeBoodt and D. Grabriels (eds.). Assessment of erosion, Wiley, London. Mitchell, J.K., S. Mostaghimi, D.S. Freeny, and J.R. McHenry. 1983. Sediment deposition estimation from cesium-137 measurements. Water Resour. Bull. 19:549-555. Mitchell, P.I., W.R, Schell, A. McGarry, T.P. Ryan, J.A. Sanchez- Cabaza Vidai-Quadras. A d ,an . 1992. Studieverticale th f o s " distributio IMf Csno , mCs, ^Pu, *°Pu, ^'Pu, M 2IOfaa,d n Pi ban ombrogenous mires at midlatitudes. J. Radiât. Nucl. Art. 156:361-387. Moeller, R.E. . OldfieldF , d P.Gan , . Appleby. 1984. Biological mixing and its stratigraphie implications in Mirror Lake (New Hampshire, U.S.A.). Verhalt Internat. Verein. Limnol. 22:567- 572. Möesy, I.S. Sälägean Uray. I d . ,an 1989 . Urmärirea acumulärii unor radionucliz sedimenn ii sestoni ts . Zgiena, Medicina Muncii is Mediciniä Socialä 38:49-52. (Romanian) Mohamad, D.B. 1982. Application of Cs-137 techniques to problems of sediment redistribution in Sungai Lui representative basin, Selangor, Malaysia: Par . RegionaI t l Cooperative Agreement Report HAL 2623/RI/A6, 5 pp. International Atomic Energy Agency, Vienna, Austria. Momoshima, N. and E.A. Bondietti. 1994. The radial distribution of Sr-9 Cs-13d 0an treesn 7i Environ. .J . Radioact. 22:93-109. Morgan, I.J., P. Tytler, and M.V. Bell. 1993. The accumulation of 137-caesium from fresh f Atlantiwateo y y alevinb rfr cd an s salmon and brown trout, J. Fish Biol. 43:877-888. Moore, P.D. 1974. Lead accretion in alluvial deposits. Nat. 250:288-289. Morris, J.D. 1991. Applicatio cosmogenif no c '°B problemeo t e th n si earth sciences. Ann. Rev. Earth Planet. Sei. 19:313-350. Moulin, A.P., D.W. Anderson . MellingerM d an , . 1994. Spatial variabilit f wheao y t yield, soil propertie d erosioan s n i n hummocky terrain. Can Soi. .J l Sei. 74:219-228. Muller, R.N., D.G. Spurgel. KohnB d .an , 1977. Behaviod an r transport of industrially deprived plutonium in the Great Miami River, Ohio. Health Phys. 33:411-416.

168 Muller, R.N., D.G. Spurgel Kohn. B d . ,an 1978 . Erosional transport and depositio plutoniuf no cesiusmald o man tw n lmi midwestern watersheds Environ. .J . Qual. 7:171-174. Müller, V.J., R. Winkler, and C. Sossau. 1991. Untersuchungen zur l37Cs-activität von schwebstoiffen und zum partikularen 137Cs- flu Ammersem xi e (Oberbayern). Zeit. Hasser Abwasser Forschung 24:165-171. (German)

Mclntyre, S.C., J.W. Naney, and J.R. Cooper. 1991. Long-term Cs-137 and soil loss from field plots. Proc. Fifth Federal Interagency Sedimentation Conference 5-3. ,pp 35-39- . Mclntyre, S.C., J.W. Naney J.Rd ,an . McHenry. 1989. Quantification of lake sedimentation rates utilizing radioisotopes presenn ti e environmentth sitf . eOf 1-5 ,pp : assessment .In A Publ,EP . 440/5-89-001, USEPA, Washington, DC. McKinley, I.G., M.S. Baxter, D.J. Ellett, and W. Jack. 1981a. Tracer application Herbiese th f o radiocesiuf so a , se Estuar. e th n mi ' Coastal Shelf Sei. 13:69-82. McKinley, I.G., M.S. Baxter, and W. Jack. 1981b. A simple model of radiocesium transport from Windscale to the Clyde Sea area. Estuar. Coastal Shelf Sei. 13:59-67. McLean, R.I., J.K. Summers, R.S. Olsen, S.C. Domotor, I.L. Larson, and H. Wilson. 1991. Sediment accumulation rates in Conowingo Reservoi determines ra man-mady db naturad ean l radionuclides. Estuar. 14:148-156. Menzel, R.G. 1960. Transport of strontium-90 in runoff. Sei. 131:499-500. Menzel, R.G. 1965. Soil plant relationship radioactivf so e elements. Health Phys. 11:1325-1332. Menzel, R.G. 1974. Land surface erosio rainfald nan s sourcea l f so strontium-9 streamsn 0i Environ. .J . Qual. 3:219—223. Menzel, R.G. . Jung,P . Urn. RyuK K , d ., an 1987. Estimating soil erosion losses in Korea with fallout cesium-137. J. Appl. Radiât. Isot. 38:451-454. Merefield, J.R. 1981. Caesiu up-estuarn i m y transpor sedimentf to . Marine Geol. 39:M4S-M55. Merefield, J.R. 1986. Alkali e permo-triassimetalth n i s s a c geochemical indicators of surficial processes. Chem. Geol. 56:143-158. Meriwether, J.R., J.N. Beck, D.F. Keeley, M.P. Langley, R.H. Thompson, and J.C. Young. 1988. Radionuclides in Louisiana soils Environ. .J . Qual. 17:562-568. Miller, . HeitK.MM d ..an 1986 .timA e resolution methodologr fo y assessin qualite gth lakf yo e sediment cores tha datee tar y db Cs. Limnol. Oceanogr. 31:1292-1300. 137 Miller, K.M., J.L. Kuiper, and I.K, Heifer. 1990. l37Cs fallout depth distribution foresn si t versus field sites: implicationr sfo external gamma dose rates. J. Environ. Radioact. 12:23-47. Miller, J.R d R.Fan . . Reitemeier. 1963 e leachinTh . f o g radiostrontium and radiocesium through soils. Soil Sei. Soc. Am. Proc. 27:141-144. Mishra, U.C. and S. Sadasivan. 1972. Fallout radioactivity in Indian soils. Health Phys. 23:55-62.

169 McHenry, J.R., J.C. Ritchie, andG.B. Bubenzer. 1978. Redistribution of Cs-13erosionao t e 7du l processe Wisconsia n si n watershed, pp. 495-503. In: D.C. Adriano and I.L. Brisbin Jr. (eds.). Environmental chemistry and cycling processes. USDOE CONF-760429 DepartmenS ,U Energyf to , Washington. ,DC McHenry, J.R., J.C. Ritchie, and C.M. Cooper. 1980. Rate of recent sedimentatio Lakn ni e Pepin. Water Resour. Bull. 16:1049-1056. McHenry, J.R., J.C. Ritchie, C.M. Cooper. VerdonJ d an ,. 1984. Recent rate sedimentatiof so Mississippe th n i n i River. pp , 99-117 J.G: .In . Wiener, R.V. Anderson d D.R,an . McConville (eds.), Contaminant e uppeth rn i sMississipp i River, Butterworth Publishers, Boston. ,MA McHenry, J.R., J.C. Ritchie, and A.C. Gill. 1973a. Nitrogen, phosphorus, and other chemicals in sediments from reservoirs in North Mississippi. Mississippi Water Resour. Conf. Proc., pp. 1-13. McHenry, J.R., J.C. Ritchie A.Cd ,an . Gill. 1973b. Accumulatiof no fallout n soil i cesiud sediment an 7 s 13 m n selectei s d watersheds. Water Resour. Res. 9:676-686. McHenry, J.R., J.C. Ritchie, and J. May. 1975. Recent sedimentation lowee rateth rn si Mississipp i River Valley: Lake Verret-Lake Palourde, Louisiana. Mississippi Water Resour. Conf. Proc., pp. 13-23. McHenry, J.R., J.C. Ritchie . VerdonJ d an ,. 1976. Sedimentation rates in the Upper Mississippi River, pp. 1339-1349. In: River '76 symposium on inland waterways for navigation, flood contro d watean l r diversion. American Societ f Civio y l Engineers, New York. McHenry, J.R., F.R. Schiebe, J.C. Ritchie C.Md ,an . Cooper. 1984. Deposited sediment Lakn i s e Chicot 18-47. ,pp J-F : .x In Ni , and F.R. Schiebe (eds.), Limnological studies of Lake Chicot, Arkansas. Quachita Baptist College, Arkadelphia. ,AR Mclntyre, S.C. 1993. Reservoir sedimentation rates linked to long- term change agriculturan i s l land use. Water Resour. Bull. 29:487-495. Mclntyre, S.C., J.C. Lance, B.L. Campbell, and R.L. Miller. 1987. Using cesium-13 o estimatt 7 e soil erosio a clearcu n o n t hillside. J. Soil Water Conserv. 42:117-120. Mclntyre, S.C J.Wd .an . Naney. 1990. Reelfoot Lake sedimentation rate sourcesd san . Water Resour. Bull. 26:227-232. Mclntyre, S.C. and J.W. Naney. 1991. Sediment deposition in a forested inland wetland with a steep-farmed watershed. J. Soil Water Conserv. 46:64-66. Mclntyre, S.C., J.W, Naney W.Rd ,an . Berkas. 1988. Measuremenf o t recent sediment deposition in Lake Taneycomo using cesium-137. Abstract e 198f th Papero s r 8 fo sAnnua l e Meetinth f o g American Society of Limnology and Oceanography, Boulder, CO.

McDougall Hilton . JenkinsJ . A , d ,S. ,an . 1991 dynamiA . c modef lo cesium transpor n lake i td thei an s r catchment. Water Res. 25:437-445. McFarlane, D.J., R.J. Loughran d B.Lan , . Campbell. 1992. Soil erosio agriculturaf no l lan western di n Australia estimatey db caesium-137. Aust Soi. .J l Res. 30:533-546. McGee, E.J., H.J. Synnott P.Ad ,an . Colgan. 1993methow ne r A .fo d predictio radiocesiuf no m level vegetationn si : evidence from Irish upland Environ. .J . Radioact. 18:53-70.

170 McGee, E.J., H.J. Synnott, M. Keatinge, and P.A. Colgan. 1993. Persistence and prediction of radiocaesium levels in animals grazing in semi-natural environments. Sei. Total Environ. 138:91-99. McHenry, J.R. f trace1968o e Us r. technique n soii s l erosion research. Trans. Am. Soc. Agric. Engr. 11:619-625. McHenry, J.R. 1975. Reservoir sedimentation. Water Resour. Bull. 10:329-337. McHenry, J.R. and G.D. Bubenzer. 1985a. Estimating erosion from °'Cs activity measurements!. Am. Soc. Agric. Engr. Paper No. 82- 2034. McHenry, J.R. and G.D. Bubenzer. 1985b. Field erosion estimated from s activit'C D y measurements. Trans . SocAn . . Agric. Engr. 28:480-483. McHenry, J.R., C.M. Cooper J.Cd ,an . Ritchie. 1982. Sedimentation ni Wolf Lake, Lower Yazoo River Basin, Mississippi Freshwate. .J r Ecol. 1:547-558. McHenry, J.R. and S.C. Mclntyre. 1984. Recent sedimentation rates in Norto tw h America impoundments with watershed predominantln yi cropland, pp. 205-211. In: R.J. Loughran (ed.), Drainage basin erosio d sedimentationnan , Univ. Newcastle Soutw ,Ne h Wales, Australia. McHenry, J.R J.Cd .an . Ritchie. 1975. Redistributio f Cs-13no n 7i southeastern watersheds, pp. 452-461. In'. F. G. Howell, J.B. Gentry, and M. H. Smith (eds.), Mineral cycling in southeastern ecosystems, Symposium Series CONF-740513, Environmental Research and Development Administration, Washington, DC. McHenry, J.R. and J.C. Ritchie. 1977a. Estimating field erosion losses from fallout Cs-137 measurements. IAHS Publ. No. 122: 26-33. McHenry, J.R. and J.C. Ritchie. 1977b. Physical and chemical parameters affecting transpor I37f n o aritCi s d watersheds. Water Resour. Res. 13:923-925. McHenry, J.R J.Cd an .. Ritchie. 1980. Dating recent sedimentn i s impoundments. Symposiu n surfaco m e water impoundments. Am . Soc. Civil Engr. Yorkw ,1279-1289Ne . .pp .

Martz, L.W. and E. de Jong. 1985, The relationship between land surface morpholog d soiyan l erosio depositiod nan smala n ni l Saskatchewan basin, pp. 1-19. In: Proceedings of the seventh hydrotechnical conference, Canadian Society for Civil Engineering Annual Conference 1985. Martz Jonge d , . L.W.E 1987d .an . Using cesium-13 o assest 7 e th s variability of net soil erosion and its association with topography in a Canadian prairie landscape. Catena 14:439-451. Martz, L.W. and E. de Jong. 1991. Using cesium-137 and landform' classificatio develoo t nt soi ne l a p erosion budgea r fo t small Canadian prairie watershed. Catena 18:289-308. Mathewes, R.W J.Md .an . D'Auria. 1982. Historic change urban a n sni watershed determine y polleb d d geochemicaan n l analysef o s lake sediment. Can. J. Earth Sei. 19:2114-2125. Matisoff 1984. ,G . Mathematical model bioturbationf so 289-330. ,pp . In: P.L. McCal M.J.Sd an l . Tevesz (eds.), Animal sediment relations: the biotic alteration of sediment, Plenen) Press, New York.

171 Matisoff, G. and J.A. Robbins. 1987. A model for biological mixing of sediments. J. Geol. Education 35:144-149. Matschullat, V.J., H. Heinrichs, J. Schneider, and M. Strum. 1987. Schwermetallgehalt n Seesedimentei e Westharzes de n s (BRD. ) Chem. Erde 47:181-194. (German) Matsunami . MizohataA . Mamuro, T T. ,d an ,. 1979. Observationf o s depositio atmospherid nan c concentratio 2lf °Pbno , 7 Bel37d C,an s in Osaka. Annual Kept.. Radiât. Cent.. Osaka Perfect. 20:1-4. Maulé, C.P M.Jd .an . Dudas. 1989. Preliminary identificatio soif no l separates associated with fallout 13Cs. Can . SoiJ . l Sei. 69:171-175. McCabe, W.J. and W.J. Mason. 1982. A falls dam, Otago, sedimentation rates measured by caesium-137 profiles. Institute of Nuclear Studies INS-R-309, Lower Hutt Zealandw ,Ne . McCall, P.L., J.A. Robbins, and G. Matisoff. 1984. 137Cs and 210Pb transport and geochronologies in urbanized reservoirs with rapidly increasing sedimentation rates. Chem. Geol. 44:33-65. McCallan, M.E., B.M. O'Leary, and C.W. Rose. 1980. Redistribution of caesium-137 by erosion and deposition on an Australian soil. Aust. J. Soil Sei. 18:119-128. McCallan, M.E. and C.W. Rose. 1977. The construction of a geochronolog alluviar yfo l deposit Condamine th n si e Plaid nan the estimatio areae th lf n o variatio erosion ni n intensitn i y the Upper Condamine drainage basin. Technical Report 2/77, Griffith Univ., Australia. pp 6 ,1 McCartney, M., P.J. Kershaw, D.S. Woodhead, and D.C. Denoon. 1994. Artificial radionuclide e sediment th e Iris n th i s hf so Sea . Sei. Total Environ. 141:103-138.

Mundschenk, V.H. 1983 r SorptioZu . n Cäsiu n schwebstofvo m n a f sediment des Rheins am beispiel der nuklide 133Cs, l34Cs und l37Cs. Deutsche Gewasserkundliche Mitteilungen 27:62-68. (German) Murdock, R.N., M.S. Johnson, J.D. Hemingway, and S.R. Jones. 1993. Physicochemical characteristics of radionuclides associated with sediment from a contaminated fresh water stream. Environ. Tech. 14:639-648. Murray, A.S. . CaitcheonG , , J.M. . CrockfordOlleyH d an , . 1990.' Methods of determining the source of sediments reaching reservoirs: targeting soil conservation. ANCOLD Bull. 85:61- 70. Murray, A.S. Marten,. R Johnston. ,A Martin. P d ,an . 1987. Analysis of naturally occurring radionuclide t a environmentas l concentrations Radiât. .J . Nucl. Chem. 115:263-288. Murray, A.S., L.J. Olive, J.M. Olley, G.G. Caitcheon, R.J. Wasson, and P.J. Wallbrink. 1993. Tracin e sourcth g f suspendeo e d sediment in the Murrumbridgee River, Australia. IAHS Publ. No. 215:293-302. Murray, A.S., J.M. Olley d P.Jan , . Wallbrink. 1993. Natural radionuclide behavio fluvian i r l environments. Radiât. Prot. Dosim Press)n (I . . Murray, A.S. . StantonR , , J.M. . MortonR Olley d an ,. 1993. Determining the origins and history of sedimentation in an underground river system using natura d fallouan l t radionuclides Hydrol. .J . 146:341-359.

172 Murray, J.W. 1987. Mechanisms controllin distributioe gth tracf no e elements in oceans, pp. 153-183. In: R.A. Hites and S.J. Eisenreich (eds), Sources and fates of aquatic pollutants, Advances Cheat. Series 216:153-183. Myttenaere W.R, ,C. . Schell Thiry. ,Y . Sombre,L Ronneau. ,C d ,an J.V. Deschrieck. 1993. Modelling of Cs-137 cycling in forests recen- t development researcd san h needed. Sei. Total Environ. 136:77-91. . SaikiM Nagayad .an 1967. Y , . Accumulatio f radionuclideo n n i s coastal sediments of Japan (I) fallout radionuclides in some coastal sediments in 1964-1965. J. Radiât. Res. 8:37-43. Nakamura, K. and Y. Nagaya. 1975a. Accumulation of radionuclides in coastal sediments of Japan (II) Content of fission products in some coastal sediments collected in 1966-1972. J. Radiât. Res. 16:184-192. NagayaNakamura. Y d an . . 1975b,K . Dispersio d accumulationan f o n radionuclides in sediments of Urazoko Bay (I)- J- Oceanographical Soc. Japan 31:145-153. Nakamura, K. and Y. Nagaya. 1985. Accumulation of cesium-137 and plutonium-239, 240 in sediments of the coastal sea and the north Pacific, pp. 171-180. Jn: A. Hattori (ed.), Marine estaurine geochemistry, Lewis Publishers., Chelsea. ,MI

National Academ f Scienceo y . 1971. Radioactivit e marinth n i ey environment. National Academ Sciencef yo , Washington. ,DC Natural Environmental Research Council (UK). 1993. Radiocaesiun i m natural K coordinateU system a - s d study . EnvironJ . . Radioact. 18:133-lT9. Navas, A. and D.E. Walling. 1992. Using caesium-137 to assess sediment movemen slopen to semiaria n si d upland environment in Spain. IAHS Publ. Mo. 209:129-138. Navosha, Y.Y., S.G. Prokhorov, V.P. Strigutskiy, and A.E. Tomson. 1992. Interaction of humic substances with metal ions. Eurasian Soil Sei. 24:1-6. (Translated from Pochvovedeniye 1:109-113, 1992) Neil, D.T. and R.K. Mazori. 1993. Sediment yield mapping using small dam sedimentation surveys, Southern Tablelands w SoutNe , h Wales. Catena 20:13-25. Nelson, J.L. , R.W. Perkins, J.M. Neilsen, and W.L. Hausheld. 1966. .Reaction of radionuclides from Hanford reactors with Columbia River sediments . 139-161pp , m DisposaI . f radioactivo l e waste in seas, oceans, and surface waters. STI/PUB/126-139- 161, International Atomic Energy Agency, Vienna, Austria. Nifontova, M.G V.Nd .an . Alexashenko. 1992. Conten Sr-9f o td an 0 Cs-134, Cs-137 in fungi, lichens, and mosses in the vicinity e Chernobyoth f l Nuclear Power Plant. Sovie . EcolJ t . 23:152-155.

Nijampurkar, V.N. and O.K. Rao. 1990. Evidence of Chernobyl fallout oa temperatn e Himalayan glacier. Current Sei. 59:1239-1241. Nisbet, A.F. . S . Shaw,B Salbu d .an , 1993. Associatiof o n radionuclides with different molecular size fraction soin i s l solution: implications for plant uptake. J. Environ. Radioact. 18:71-84. Nisbet . Shaw,S A.Fd .an . 1994a. Summar 5-yeaa f yo r lysimeter study on the time-dependent transfer of Cs-137, Sr-90, Pu-239, Pu-240 and Am-241 to crops from three contrasting soil types. 1. Transfer to the edible portion. J. Environ. Radioact. 23:1-17.

173 Nisbet, A.F. and S. Shaw. 1994b. Summary of a 5-year lysimeter study e timth e n o dependent transfe f Cs-137o r , Sr-90, Pu-239, Pu-240 and Am-241 to crops from three contrasting soil types. 2. Distribution between different plant parts . EnvironJ . . Radioact. 23:171-187. Nishita, H., B.W. Kowalewsky, A.J, Steen, and K.H. Larson. 1956. Fixation and extractibility of fission products contaminating various soils and clays: 1. "sr, "Y, 106Ru, 137Cs, and l44Ce. Soil 81:317-326i Se . Nishita A.J, ,H. . Steen K.Hd ,an . Larson. 1958. Releas Srd f eo 9an 0 Cs from Vina Loam upon prolonged cropping. Soil Sei. 86:195- 20113.7

Nolin, M.C., Y.Z. Cao, D.R. CooteWang. C d .,an 1993. Short-range variabilit f fallouo y tn unerode a 137 n Ci s d forest soil. Can. J. Soil Sei. 73:381-385. Nordlinder, S., U. Bergström, J. Hammar, and M. Notter. 1993. Modelling turnover of Cs-137 in two subarctic salmonid ecosystems. Nordi Preshw. cJ . Res. 68:21—33. Norris, V. and S.J. Perrens. 1990. Analysis of variability of caesium-13 n soili 7 n northeri s n N.S.W. . 187-191,pp m I . Proceedings of conference on agricultural engineering,- Hawkesbury Agricultural College, Australia. Norton, S.A. 1986. A review of the chemical record in lake sediment of energy relate r pollutios effectai dit d n lakeso san n . Water Air Soil Pollut. 30:331-345. Nozaki , D.JY. , . DeMaster, D.M. Lewis d K.Kan , . Turekain. 1978. Atmospheric 210Pb fluxes determined from soil profiles. J . Geophys. Res. 83(C8):4047-4051. Nriagu, J.O. 1984. Role of inland water sediments as sinks for anthropogenic sulfur. Sei. Total Environ. 38:7-13. Nriagu, J.O., A.L.W. Kemp, H.K.T. Wong, and N. Harper. 1979. Sedimentary record of heavy metal pollution in Lake Erie. Geochim. Cosmochim. Acta 43:247-258. Nyffeler, U.P. ,P.Hd Y.Han ., .SantschiLi . 1984 kineti.A c approach to describe trace element distribution between particled san solution in natural aquatic systems. Geochim. Cosmochim. Acta 48:1513-1522. Nygren, P., P. Hari, T. Raunemaa, M. Kulmala, S. Luokkanen, M. Holmberg . NikinmaaE d an , . 1994. Behaviou f Cs-13o r 7 from Chernobyl fallou scota n ti s pine canop Southern yi n Finland. Can. ForesJ . t a RecherchRes. CanL J e - d . e Forestière 24:1210-1215. Nyhlan, J.W., G.C. White, T.G. Schonfeld and G. Trujillo. 1983. An evaluatio f soio n l samplin 137r Cfo gs using various field- sampling volumes. Health Phys. 44:541-552. Oenema, O. and R.D. DeLaune. 1988. Accretion rates in salt marshes in Eastern Scheldt, South-west Netherlands. Estaur. Coast. Shelf Sei. 26:379-394. Officer, C.B. 1982. Mixing, sedimentatio ndatine rateag r d fo g san sediment cores. Marine Geol. 46:261-278. Officer, C.B. and D.R. Lynch, 1982. Interpretation procedures for the determination of sediment parameters from time-dependent flux inputs. Earth Planet. Sei. Lett. 61:55-62.

174 O'Hara, S.L., F.A. Street-Perrott, and T.P. Burt. 1993. Accelerated soil erosion aroun a Mexicad n highland lake causey b d prehistoric agriculture. Nat. 362:48-51. d C.TOhnoan . . HessT , . 1994. Level f Cs-13o s d K-4 an 7n woo 0i d ash-amended soils. Sei. Total Environ. 152:119-123.

Okuda, S. 1982. Sedimentary environments in Lake Biwa. Estimates of recent sedimentation rates. Kankyo Gijutsu 11:401-403. (Japanese) Oldfield, F. 1977. Lakes and their drainage basins as units of sediment-based ecological studies. Prog. Phys, Geog. 1:460-504. Oldfield . F 1981, . Peatd lakan se sediments: formation, stratigraphy, description and nomenclature. In: A. Gourdie (ed.), Geomorphological techniques, George Alie Onwin,d an n " London. Oldfield, F. and P.G. Appleby. 1984. A combined radiometric and mineral magnetic approach to recent geochronology in lakes affecte catchmeny db t disturbanc sedimend ean t redistribution. Chem. Geol. 44:67-83. Oldfield P.G, ,F. . Appleby R.Wd ,an . Battarbee. 1978. Alternative 210Pb dating: results froGuinew mNe a Highland Lougd san h Erne. Nat. 271:339-342. Oldfield P.G", ,F. . Appleby, R.S. Cambray, J.D. Eakins, K.E. Barber, R.W. Battarbee, G.R. Pearson J.Md ,an . Williams. 1979.2IO Pb,

Cs, Panud profiles in ombrotrophic peat. Oikos 33:40-45.

137 2W Oldfield P.G, ,F. . Appleby Petit. D d ,.an 1980 .re-evaluatioA f no lead-210 chronology and the history of the total influx in a small South Belgium pond. Ambio 9:97-99. Oldfield P.G, ,F. . Appleby Thompson. R d ,an . 1980. Palaeoecological studie highlane f lakeso th n si Papu f do Guineaw e aNe Th . .I chronology of sedimentation. J. Ecol. 68:457-477. Oldfield, F., R.W. Battarbee, and J.A. Dearing. 1983. New approaches to recent environmental change. Geographica 149:167-181. lJ . cldfield, F. and B. Mäher. 1984. A mineral magnetic approach to erosion studies, pp. 161-168. Im R. J. Loughran (ed.), Drainage basin erosio sedimentationd nan , Univ. Newcastlew ,Ne South Wales, Australia. Oldfield Richardson. N , F. , , P.G 1993. ApplebyYu . .L Am-24d ,an 1 and Cs-137 activity in fine grained saltmarsh sediments from Neae partth r f so Iris Shorelinea hSe Environ. .J . Radioact. 19:1-24. Oldfield, F., A.T. Worsley, and P.G. Appleby. 1985. Evidence from lake sediments for recent erosion rates in the highlands of Papua New Guinea, pp. 185-196. Jn: I. Douglas and T. Spencer (eds , Environmenta) . l chang tropicad ean l geomorphology, Alien d Unwinan , London. Olley, J.M., A.S. Murray, D.H. Mackenzie . EdwardsK d an , . 1993. Identifying sediment source a gullie n i s d catchment using natura d anthropogenian l c radioactivity. Water Resour. Res. 29:1037-1043.

Olley, J.M., A.S. Murray . P Wallbrink, . CaitcheonG ,. R d an , Stanton. 1991. The use of fallout nuclides as chronometers, PP- 51-55. Jn: Workshop on quaternary dating, Australian National Univ., Canberra.

175 Olsen, C.R. 1979. Radionuclides, sedimentation and the accumulation of pollutant Hudsoe th n ni s estuary. Ph.D. Thesis w Yor,Ne k Univ. Yorkw ,Ne . Olsen, C.R., N.B. Cutshall, and I.L. Larsen- 1982. Pollutant-particle association dynamicd san coastan si l marine' environments: a review. Marine Chem. 11:501-533. Olsen, C.R., N.B. Cutshall, I.L. Larsen, B.J. Simpson, R.M. Trier, . BoppF . anR d. 1985 n estuarinA . e fine-particle budget determined from radionuclide tracers. Geo-Marine Lett. 4:157-160. Olsen, C.R., I.L. Larsen, N.B. Cutshall, J.F. Donoghue, O.P. Bricker, and B.J. Simpson. 1981. Reactor-released radionuclides in Susquehanna River sediments. Nat. 294:242- 245. Olsen, C.R., I.L. Larsen, P.D. Lowry d N.Ban , . Cutshall. 1986. Geochemistr d deposition river-estuarini an y e B 7 f o n d an e coastal water. J. Geophys. Res. 91:896-908. Olsen, C.R., I.L. Larsen, P.D. Lowry, N.B. Cutshall, J.F. Todd, G.T.F. Wong, and W.B. Casey. 1985. Atmospheric fluxes and marsh-soil d inventorie2l °Pban . GeophysJ .e B 7 f o s. Res. 90:10487-10495. Olsen, C.R., B.J. Simpson, T.B. Peng, R.F. Bopp, and R.M. Trier. 1981. Sediment mixing and accumulation rates effects on radionuclide depth profile Budson i s n estuary sediments. J . Geophys. Res. 86:11020-11028. Olsen, C.R., B.J. Simpson d R.Man ,. Trier. 1981. Plutonium, radiocesiu radiocobald man sedimentn ti e Budsoth f so n river estuary. Earth Planet. Sei. Lett. 55:377-392. Olsson, I.U. 1986. Radiometrie dating, pp. 273-312. In: B.E. Berglund (ed.) Handboo f o Holocenk e paleoecologd an y paleohydrology, Wiley, London. Osborne, P.L. and B. Moss. 1977. Paleolimnology and trends in phosphorus and iron budgets of an old man-made lake, Barton Broad Norfolk. Freshwater Biol. 7:213-233. Ostlund, P. and R.O. Ballberg. 1991. Plutonium in sediments apparent half-lives. Environ. Geol. Water 17:195-200. Ostrova, I.V., A.N. Silant'ev, L.F. Litvin, V.N. Golosov, and I.G. Shkuratova. 1990. Assessing the intensity of erosional accumulation processe contene th y scaesium-13b f to soilsn 7i . Geografiya 5:79-85. (Russian) Papaste . ManolopoulouM f anou , C. . ,CharalamnousS d an , . 1988. Cesium-13 n soii 7 l from Chernobyl fallout. Health Phys. 55:985-987.

Papastefanou Manolopoulou. M , , ,C Sawidis. T d ,an . 1992. Residence time and uptake rates of Cs-137 in lichens and mosses at temperature Latitude (40-Degrees-N). Environ. Internat. 18:397-401.

Pardue, J.B .R.D, . DeLaune, W.B. Patrick J.Bd ,an . Whitcomb. 1989. Effec f redoo t x potentia n fixatioo ln laki Cs I37 ef o n sediment. Health Phys. 47:781-789. Parise, G., G. Paleologo, G. Premazzi, P. Pulici, A. Riva, T. Ruaro, R. Bugini Capitanie D Maccagni. . A ,L d ,an . 1981. Lake Como' (Northern Italy): mineralogical, chemical and biological characteristic e sedimentsth f so . European Applied Research Rept. Environ, ana Nat. Res. Sect. 1(3):385-416.

176 Premazzi. G Parise d an . ,.G 1986 fenoraen.I compattazioni id e nella geocronologia del sediment! lacustri. Acqua-Aria 8:783-790. (Italian) Parker J.I d D.N.an . Edgington. 1976. Concentratio f diatoo n m frustule Lakn si e Michigan sediment cores. Limnol. Oceanogr. 21:887-893. PatelPatelPawar. . S S , d ,.,B. an 1978. Desorptio radioactivitf no y from nearshore sediment. Estuar. Coast. Marine Sei. 7:49-58. Patrick, W.H. Jr and R.D. DeLaune. 1990. Subsidence, accretion, and a levese l ris n sout i en Francisc Sa h y marshesBa o . Limnol. Oceanogr. 35:1389-1395. Pattenden, N. and W.A. McKay. 1994. Studies of artificial radioactivity in the coastal environment of northern Scotland: A review. J. Environ. Radioact. 24:1-51. Payne, B.R. 1985. Measuremen ratef to accumulatiof so sedimentf no s from radionuclide data, pp. 219-224. In: Methods of computing sedimentation in lakes and reservoirs. UNESCO Technological Reports in Hydrology, UNESCO, Paris. Peart, M.R D.Ed .an . Walling. 1986. Fingerprinting sediment source: example th drainaga f eo e basi Devonn ni . IAE,UK S Publ. .No 159:41-55. Peart, M.R. and D.E. Walling. 1988. Techniques for establishing suspended sediment sourceo drainagtw n i s e basin Devonn i s , UK: a comparative assessment. IAHS Publ. No. 174:269-279. Pegoyev, A.N S.Dd .an . Fridman. 1978. Vertical profile cesiumf so - 137 in soils. Pochvovedeiye 8:77-81. Pempkowiak, J. 1991. Enrichment factors of heavy metals in the southern Baltic surface sediments dated with 210l37d PCsan b. Environ. Internat. 17:421-428. Pempkowiak Skiba. D d .an 1988. ,J detenninatioe .Th accumulatiof no n rates in the recent Baltic Sea sediments on the basis of 2I0pb and Cs profiles . 824-832pp , m I Proceedings. I XV . Conferenc r37 e Baltic Oceanographers Vol. 2. Institute of Marine Research, Kiel, Russia.

Pendleton, R.C W.Cd .an . Hanson. 1958. Absorptio cesium-13f o n y 7b component n aguatia f o sc community . 419-422pp , : In . Proceedings of the international conference on the peaceful use of atomic energy 18. United Nations, Geneva, Switzerland. Peng, T.H., W.S. Broecher W.Hd ,an . Berger. 1979. Rate benthif so c mixin f deep-seo g a sediment s determinea s y radioactivb d e tracers. Quat. Res. 11:141-149. Pennington, W. 1972. The recent sediments of Windermere. Freshwater Biol. 3:363-382. Pennington . 1974W , . Sesto sedimend an n t formatio n Fivi n e Lake District lakes Ecol. .J . 62:215-251. Pennington 1978. ,W . Response somf so e British lake paso st t changes in theino lane r us dcatchments . Verb. Internat. Verein. Limnol. 20:636-641. Pennington, W. 1979. The origins of pollen "in lake sediment: an enclosed lake compared with one receiving inflow streams. New Phytol. 83:189-213. Pennington, W. 1981. Records of a lake's life time: the sediments. Hydrobiologia 79:197-219.

177 Pennington, W-, R.S. Cambray, J.D. Eakins, and D.D. Harkness. 1976. Radionuclide datine recenth f tgo sedimen Blelhan i t m Tarn. Freshwater Biol. 6:317-331. Pennington, W., R.S. Cambray, and E.M. Fisher. 1973. Observations of lake sediment using fallou ttracera 137 s Ca s . Nat. 242:324- 326.

Pennock, D.J., D.W. JongAndersone d . .E 1994d ,an . Distributiof no cesium-137 in uncultivated black chernozemic landscapes. Can. J. Soil Sei. 74:115-117. Pennock Jonge d , . D.J.E 1987d . influencan e .Th slopf eo e curvature on soil erosion and deposition in hummock terrain. Soil Sei. 144:209-217. Pennock e Jongd , . .E D.J 1990ad an . . Spatial patter f soio n l redistribution in Boroll landscapes, southern Saskatchewan, Canada. Soil Sei. 150:867-873. Pennock, D.J. and E. de Jong. 1990b. Rates of soil redistribution associated with soil zones and slope classes in southern Saskatchewan. Can Soi. .J l Sei. 70:325-334. Penttila Kairesalo. T , Uusirauva. ,S. A d ,an . 1993 occurrence .Th e and bioava il ability of radioactive Cs- 137 in small forest lake Southern si n Finland, Environ. Pollut. 82:47-55. Perkins, R.W. and C.W. Thomas. 1980. Worldwide fallout, pp. 53-82. In: W.C. Hanson (ed.), Transuranic e elementth n i s environment. DOE/TIC-22800. Department of Energy, Washington, DC.

Persson, C. , R. Henning, and L.E. de Geer. 1987. The Chernobyl accident-A meteorological analysis of how radionuclides reached and were deposited in Sweden. Ambio 16:20-31. Petersen, R.C. Jr, L. Lander, and H. Blanck. 1986. Assessment of the e Chernobyimpacth f o t l reactor accidene biotth f o an o t Swedish stream lakesd san . Ambio 15:327-331. Peterson, S.A. 1982. Lake restoration by sediment removal. Water Resour. Bull. 18:423-435. Peterson, W., H.D. Knauth, and R. Pepelnick. 1990. Vertical distributio Chernobyf no l isotope theid san r correlation with heavy metals and organic carbon in sediment cores of the Elbe estuary. Sei. Total Environ. 97/98:531-547. PetitThomas. M Lamberts. L , d ,D. ,an . 1987. Origi heavf no y metal fluxeMeuse th eo st rive Southern ri n Belgium using 210Pb-dated water-meadow sediments Environ. .J . Radioact. 5:303-316. Phillips, F.M., G.I. Smith, H.W. Bentley, D. Elmore, and H.E. Gove. 1983. Chlorine-36 datin f salino g e sediments: preliminary results from Searles Lake, California. Sei. 222:925-927. Pickering, R.J. 1969. Distributio f radionuclideo n n bottoi s m sediment of the Clinch River Eastern Tennessee. USGS Professional Paper Washington, 433-Hpp 5 ,2 . ,DC Pickering, R.J., P.H. Carrigan Jr. F.Ld an , . Parker. 1965e .Th Clinch River Study - an investigation of the fate of the radionuclides release surface th o dt e streams. USGS, Circular 497, 12 pp, Washington, DC, Pickering, R.J., P.H. Carrigan Jr. . ,TamuraT , H.H. Abee, J.W. Beverage, and R.W. Andrews, Jr. 1966. Radioactivity in the bottom sediments of the Clinch and Tennessee Rivers, pp. 57- Disposa: In . f radioactiv86 o l e wast n seasi e , oceand an s surface waters, International Atomic Energy Agency, Vienna, Austria. 178 Pierson, D.H., R.S. Cambray, P.A. Cawse, J.D. Eakins d N.Jan , . Patterden. 1982. Environmental radioactivit Cumbrian yi . Nat. 300:27-31. Pierson, D.H.,, R.N. Crookes and E.M.R. Fisher. 1960. Radioactive raind an fallou.r AERE-ai n i t R 3358. HMSO, London. Pierson, Salmon. D.HL d .an . 1959. Gamma radiation from deposited fallout. Nat. 184:1678-1679. Pietilainen, O.P. and P. Ekholm. 1993. Origin of eroded material in a small agricultural drainage basi southwestern i n n Finland. Aqua Fenn 22:105-110. Finder, J.E. Ill, C.T. Garten . PaineJr.D d ,.an 1980. Factors affecting radiocesium uptak y b plante s inhabitina g contaminated floodplain. Acta (Ecologica 1:3-10.

Pisarev, V.V., I.A. Koloskov, V.M. Kuznetsova d I.S,an . Tsybizov. 1972. Leaching of strontium-90 from soil by surface water. Soviet Soil Sei. 3:66-75. (Russian) Plato, P.A. 1972. Distribution of cesium-137 and naturally occurring radionuclide sedimentn i s Lakf o s e Michigan. Radiât. Health Data Reports 13:181-188. Plato, P.A. riverf 1974o e predico s.t Us t accumulatio sedimenn i n t of radionuclides discharged from nuclear power plants. Health Phys. 26:489-496. Plato, P.A. 1975. Reply "Us f rivereo predico t s t accumulation i n sedimen f radionuclideo t s discharged from nuclear power plants". Health Phys. 28:635-636. Plato, P.A G.Gd .an . Goldman. fallouf 1972o e .Os t cesium-13a s 7a trace defino rt recene eth t deltaic faciè rivera f so . Radiât. Health Data Reports 13:635-657. Plato, P.A A.Pd .an . Jacobson. 1976. Cesium-13 Lakn i 7 e Michigan sediment: areal distribution and correlation with other man- made materials. Environ. Pollut. 10:19-34. Playford, K., G.N.J. Lewis, and R.C. Carpenter. 1992. Radioactive f 1990raind o an d fallou:r .en ai resulte AEA-EEn th i t o st - Unite. 0362pp 7 ,d2 Kingdom Atomic Energy Authority, Harwell, UK. Playford AdsleyToole. . I J . d K ,,an . 1993. Radioactive falloun i t rainaid 1991f ro an d :. en result AEA-EE-O498e th o st . pp 0 ,3 United Kingdom Atomic Energy Authority, Harwell, ,UK Plimentel, D.J. Alien, A. Beers, L. Guinand, R. Linder, P. McLaughlin, B. Meer, D. Musonda, D. Perdue, S. Poisson, S. Siebert, K. Stone, R. Salazar, and A. Hawkins. 1987. World agriculture and soil erosion. Biosci. 37:277-283. Popp, C.J., J.W. Hawley, D.W. . DehnM Love d .an ,f 1988o e Us . radiometric (Cs-137, Pb-210), geomorphic d stratigraphian , e technique dato st e recent oxbo wPuerco sedimentRi e oth n si drainage Grants Uranium Region, New Mexico. Environ. Geol. Water Sei. 11:253-269. Porter, C.R., C.R. Phillips, M.W. Carter. KahnB d ., an 1967e .Th caus relativelf eo y high 137Cs concentration Tampan si , Florida milk, pp. 95-101. Im B. Aberg and J.R. Hungate (eds.), Radioecological concentration processes. Pergamon Press, New York. Pourchet, M., J.F. Pinglot, and M.A. Melieres. 1989. Cesium-137 and lead-210 in Alpine sediments: measurements and modeling of mixing processes Geophys. .J . Res. 94:12761-12770.

179 Fourchât , J.FM. , . Pinglot . Reynaud L ,. Holdsworth G d an , . 1988. Identification of Chernobyl fallout as a new reference level in Northern Hemisphere glaciers Glaciolog. .J y 34:183-187. Powers F.S, ,F. . Stay W.Dd ,an , Sanville. 1975. Aquatic sediments. J. Water Pollut. Control Fed. 47:1611-1617.

Prandle, D. 1984. A modelling study of the mixing of 137Cs in the seas of the European continental shelf. Phil. Trans. R. Soc. Londo n310:407-436A . Premazzi . G 1978, . Metod i d valutaziono e __della rati d e sedimentazione. Attl Convegde i o sulla "Eutrofizzazionn i e Italia", Roma 4 Ottobr3- , e 1978. AC/2/5 . 181-195pp 5 . (Italian) Premazzi, G. 1979. The Cs-137 technique to evaluate recent sedimentation rates, pp. 181-196. In'. R. Marchetti (ed.), Convegno Sulla Eutrofizzazion n Italiaei . AC/2/45-70, Roma, Italy. . MarengoG Premazzi d an . . G ,1982 . Sedimentation a rate n i s Swiss-Italian lake measured with sediment traps. Hydrobiologia 92:603-610. Premazzi, G., A. Provini, G.F. Gaggino, and G. Parise. 1986. Geochemical trends in sediments from 13 Italian subalpine lakes 157-165. ,pp P.G: .Jn . Sly, (ed.), Sedimen wated tan r interactions, Springer-Verlag, New York. Premazzi, G. and O. Ravera. 1977.-Chemical characteristics of Lake Lugano sediments, pp. 121-124. Im H.L. Golterman (ed.), Interaction between sediment and fresh water, W.Junk B.V. Publishers, Wageningen, The Netherlands. . Lubello PretiC . Becchi I , . d L , an ,. 1993. Joint monitorinf o g hydrosedimentological events and transport of caesium-137 in a small basin. Water Sei. Tech. 28:707-711. Prokhorov, V.M. 1975. Forecasting Cs137 migratio n i soilsn . Pochvovedeniye 11:60-67. Provinid G.Fan .. A , Gaggino. 1984. Metal contaminatiod an n historical record Lakn si e Orta sediments (Northern Italy), . 318-321pp Proceeding: .In internationad s3r l symposiun o m e interactionth s between sediment d wateran s , Geneva, Switzerland. Provini, A. and G.F. Gaggino. 1985. Sediment as a record of copper pollution in Lake Orta. Verb. Internat. Verein. Limnol. 22:2390-2393. Provini G.Fd an . . Gaggino,A . 1986n .2 Deptd an h, profileCr , Cu f so in Lake Orta sediments (Northern Italy), pp.167-174. Jn: P.G. Sly (ed.), Sediment and water interactions, Springer-Verlag, New York. Provini, A., G. Premazzi, and G.F. Gaggino. 1987. Valutazione del rischio potenzial a metalld e i pesant i laghne i i mediante l'analis i sedimentide i . Ingegneria Ambientale 16:68-76. (Italian) Provin. PremazziG , A- i . GalassiS , d G.Fan , . Gaggino. 1987. Distribution of nutrients, PAHs, and radionuclides in sediment cores from Lake of Varese (N. Italy) . Proceedings of 4th international symposium in interaction between sediment and water, Melbourne Australia.

Quine, T.A. 1989. Use of a simple model to estimate rates of soil erosion from caesium-137 data Wate. ,J r Resour. 8:54-81.

180 Quine, T.A. ,. NavasA , D.E. . WallinMachinJ d an g. 1994. Soil erosio distributiod nan cultivaten no d land neas BarenarLa s centrae ith n l Ebro River basin, Spain. Land Degradatiod nan Rehabilitation 5:41-55. Quine, T.A. and D.E. Walling. 1991. Rates of soil erosion on arable field n Britaini s : quantitative data from caesium-137 measurements. Soil Use Manage. 7:169-176. Quine, T.A D.Ed .an Walling. caesium-13f 1992ao e .Us 7 measurements to investigate the relationships between erosion rates and topography . 31-48pp ,R.J: In . . Alliso d D.S.Gan n . Thomas (eds.), Environmental sensitivity, Wiley, Chichester, UK. Quine, T.A. and D.E. Walling. 1992b. Patterns and rates of contemporary soil erosion derived using caesium-137, pp. 185- 196. In'. M. Bell and J; Boardman (eds.), Past and present soil erosion: archeologica geographicad an l l perspectives, Oxbow Books, Oxford, England. Quine, T.A. and D.E. Walling. 1993. Use of caesium-137 measurements to investigate relationships between erosion rated an s topography, pp. 31-48. In: D.S.G. Thomas and R.J. Allison (eds.) Environmental sensitivity, J. Wiley and Sons, Chichester, UK. Quine, T.A., D.E. Walling d O.Tan , , Mandiringana. 1993.n A investigatio e edaphicth f o n, topographic d land-usan , e controls on soil erosion on agricultural land in the Borrowdale and Chinamora areas, Zimbabwe, based on caesium-137 measurements. IAHS Publ 217:185-196. .No . Quine, T.A., D.E. Wallin 2hang. X d .gan 1993role Th tillagf .eo n ei soil redistribution within terraced fields of the Loess Plateau, China n investigatio:A n using caesium-137 . 149,pp - 155. In: K. Banasik and A. Zbikowski (eds.), Runoff and sediment yield modelling. Warsaw Agricultural University Press, Warsaw, Poland. Quine, T.A., D.E. Walling, X. Zhang, and Y. Wang. 1992. Investigation of soil erosion on terraced fields near Yanting, Sichuan Province, China, using caesium-137. IAHS Publ. No. 209:155-168. Rafferty , D.EB. , . Dawson d P.Aan , . Colgan. 1994a. Seasonal variations in the transfer of Cs-137 and K- 40 to pasture s ingestioit gras d an sy grazinb n g animals. Sei. Total Environ. 145:125-134. Rafferty, B., D.E. Dawson, and P.A. Colgan. l?94b. Assessment of the rol f soieo l adhesio transfee th n i nf Cs-13 ro d K-4o 7an t 0 pasture grass. Sei. Total Environ. 145:135-141, Rafferty , D.EB. , . Dawson d P.Aan , . Colgan. 1994c. Soid an l radiocaesium contamination of winter fodders. Sei. Total Environ. 153:69-76.

Rapin, F. 1981. Chronologie et evolution de la contamination par les meteux lourds des sediment de la Baie des Anges (Méditerranée, France). Environ. Tech. Lett. 2:253-262. (French) Ratnikov, A.N., R.M. Aleksakhin, T.L. Zhigareva, N.I. Sanzharova, and G.I. Popova. 1993. Effectivenes meliorativf so e measures in decreasing levels of Cs-137 in harvests after the accident at the Chernobyl Nuclear Power Plant - Data from Bryansk Province, Russia. Eurasian Soil Sei. 25:123-127. Ravera . 1961,O . Sediment 31-37. Accumulatio,pp : .In f fissiono n products from fall-out in lake biota (Lake Maggiore). Contract , Repor59 t CNI-109, International Atomic Energy Agency, Vienna, Austria.

181 Premazzi. G Ravera d an . .,O 1971a .methoA studo dt e histor yth f yo any persistent pollution in a lake by the concentration of l37Cs from fall-out. Publ. Biol. Directorate, Cooun. European Communities 679:1-16. Ravera, O. and G. Premazzi. 1971b. A method to study the history of any persistent pollution in a lake by the concentration of l37Cs from fall-out, pp. 703-719. Im Radioecology applied to the protection of man and his environment. EUR 4800. • Ravera, O. and M. Viola. 1977. Sedimentation rate in a basin (Agno) of Lake Lugano . 174-178pp , : H.LIn . . Golterman (ed.), Interaction between sediment and fresh water, W. Junk B.V. Publishers, Wageningen Netherlandse ,Th . . ZariniS Raverad an . . 1987O , A .centur f variationo y n somi s e Zooplankto d zoobenthoan n s organism n i Laks e Comabbio (Northern Italy) 'read' from their remains in the lake sediment. Schweiz Hydrol. .Z . 49:93-101. Rea, O.K., R.A. Bourbonniere, and P.A. Meyers. 1980. Southern Lake Michigan sediments: changes in accumulation rates, mineralogy, and organic content Grea. .J t Lakes Res. 6:321-330. Reddy, K.R., R.D. DeLaune, W.F. DeBusk M.Sd ,an . Koch. 1993. Long- term nutrient accumulation rates in the Everglades. Soil Sei. 57:1147-1155. J Soc . .Am . Rember, W.C., T.W. Erdman, M.L. Hoffmann, V.E. Chamberlain, and K.F. Sprenke. 1993. Dating of mine waste in lacustrine sediments using cesium-137. Environ. Geol. 22:242-245. Renard, K.G., G.R. Foster, G.A. Weesies d J.Pan , . Porter. 1991. RUSLE Revised universal soil loss equation . SoiJ . l Water Conserv. 46:30-33. Richter. SchroederG , T. , . KaminskiS ,. LinderG d an ,. 1993. Transpor particlef to s contaminated with cesium radionuclides int sedimene oth Lakf to e Constance. Water Sei. Tech. 28:117- 121. Ridgeway, I.M N.Bd an .. Price. 1987. Geochemical associationd an s post-depositional mobility of heavy metals in coastal sediments: Loch Etive, Scotland. Marine Chem. 21:229-248.

Rieger, E.M., B, Claus, E. Peters, M. Schirmer, and I. Schmitz- Feuerhake. 1993. Cesium isotope-activit e Weseth n ri y ecosystem three years after the disaster at Chernobyl. Neth. J. Aquat. Ecol. 27:197-203. Kiel, G.K. 1970. Radioactive cesium in estuaries. Radiât. Health Data Reports 11:659-665. Ritchie, C.A., J.C. Ritchie G.Ld ,an . Plummer. 1971. Distributiof no fallout cesium-13 Cladonin 7i a mounds. Bryologist 74:359-362. Ritchie, J.C, 1988. Organic matter conten n sedimenti t f threo s e navigation pools alone uppeth g r Mississippi River. J . Freshwater Ecol. 4:343-349. Ritchie, J.C. 1989. Carbon conten f sedimento t n agriculturai s l reservoirs. Water Resour. Bull. 25:301-308. Ritchie, J.C., E.E.C. Clebsch, and W.K. Rudolph. 1970. Distribution f fallouo naturad tan l gamma radionuclide littern si , humus, and surface mineral soils under natural vegetation in the Great Smoky Mountains, North Carolina-Tennessee. Health Phys. 18:479-491.

182 Ritchie, J.C., C.M. Cooper J.Rd .,an McHenry. 1979. Recent sediment accumulation in natural lakes in Bear Creek watershed in the Mississippi Delta. Southeastern Geol. 20:173-180. Ritchie, J.C., C.M. Cooper, and J.R. McHenry. 1986. Sediment accumulation rate laken si reservoird san Mississippe th n si i River valley . 1357-1365pp , S.Ys in . . Wang, H.W. Shend an , L.Z. Ding (eds.), River sedimentation, Vol. Ill, Univ. Mississippi, Oxford. ,MS Ritchie, J.C., C.M. Cooper, J.R. McHenry, and F.R. Schiebe. 1983. Sediment accumulation in Lake Chicot, Arkansas. Environ. Geol. 5:79-82. Ritchie, J.C., A.C. Gill, and J.R. McHenry. 1975. A comparison of nitrogen, phosphorus, and carbon in sediments and soils of cultivated and noncultivated watershed of the North Central States. J. Environ. Qual. 4:339-341. Ritchie, J.C. and P.H. Hawks. 1979. Natural gamma radioactivity in the soils of North Mississippi. J. Mississippi Acad. Sei. 24:92-103. Ritchie, J.C., P.H. Hawks, and J.R. McHenry. 1972. Thorium, uranium, and potassium in the Upper Cretaceous, Paleocene, and Eocene sediments of the Little Tallahatchie River Watershed in northern Mississippi. Southeastern Geol. 14:221-232. Ritchie, J.C., P.H. Hawks, and J.R. McHenry. 1975. Deposition rates in valleys determined using fallout Cs-137. Geol. . SocAm . Bull. 86:1128-1130. Ritchie, J.C d J.Ran .. McHenry. 1973a. Determinatio f fallouo n t Cs-137 and natural gamma-ray emitting radionuclides in sediments. Internat. J. Appl. Radiât. Isot. 24:575-578.

Ritchie, J.C d J.Ran . . McHenry. 1973b. Vertical distributiof o n fallout cesium-13 cultivaten i 7 d soils. Radiât. Health Data Reports 14:727-728. Ritchie, J.C d J.Ran . . McHenry. 1975a. Fallout Cs-137 a too: n i l conservation research Soi. .J l Water Conserv. 30:283-286. Ritchie, J.C. and J.R. McHenry. 1975b. Fallout cesium-137 in estuarine sediments. J. Mississippi Acad. Sei. 20:34-39. Ritchie, J.C. and J.R. McHenry. 1976. Fallout Cs-137 in soils and sediment somf so e Texas watershed ecosystems 299-303. ,pp : .In C.E. Cushing (ed.), Radioecology and energy resources. The Ecological Societ f Americo y a Special Publicatio, 1 . No n Dowden, Hutchinso Rossd nan , Stroudsburg. ,PA Ritchie, J.C. and J.R. McHenry. 1977a. The distribution of Cs-137 in some watersheds in the eastern United States. Health Phys. 32:101-105. Ritchie, J.C. and J.R. McHenry. 1977b, A rapid method for determining recent deposition rate freshwatef so r sediments. pp. 203-207. In: H.L. Golterman (ed.), Interaction between sediment and fresh water, W. Junk B. V. Publishers, The Hague, The Netherlands. Ritchie, J.C d J.Ran . . McHenry. 1977c. Nitrogen, carbod an n phosphorus in soil and sediments of some small watersheds in the eastern United States Mississipp. .J i Acad. Sei. 22:7-14. Ritchie, J.C. and J.R. McHenry. 1978. Fallout Cs-137 in cultivated and noncultivated North Central United States watersheds. J. Environ. Qual. 7:40-44.

183 Ritchie, J.C d J.R.an . McHenry. 1981. Distributio f o falloun t cesium-137 in small watersheds in the United States, pp. 104- : In Internationa105. l symposiu n migratioo e m th n i n terrestrial environment f long-liveo s d radionuclides froe mth nuclear fuel cycle. International Atomic Energy Agency, Vienna, Austria.

Ritchie, J.C. and J.R. McHenry. 1982. Redistribution of fallout cesium-13 n i smal7 l watershed e Uniteth n i ds States. pp , 809-810. In: Environmental migration of long-lived radionuclides, Proceeding Series STI/PUB/597, International Atomic Energy Agency, Vienna, Austria.

Ritchie, J.C. and J.R. McHenry. 1984. Cesium-137 and sediment deposition, pp. 183-188. In: R.J. Loughran (ed.), Drainage basin erosio sedimentationd an n , Univ. Newcastle, Newcastle, Australia.

Ritchie, J.C. and J.R. McHenry. 1985. A comparison of three methods for measuring recent rate f sedimeno s t accumulation. Water Resour. Bull. 21:99-103.

Ritchie, J.C d J.R.an . McHenry. 1989. Applicatio f radioactivo n e fallout cesium-137 for measuring soil erosion and sediment accumulation rates and patterns: a review and bibliography. Hydrology Laboratory Technical Report No. 15, 67 pp, US Departmen f o Agriculturet , Agriculture Research Service, Beltsville. MD , Ritchie, J.C. and J.R. McHenry. 1990. Application of radioactive fallout cesium-137 for measuring soil erosion and sediment accumulation rate patternsd an s a review: . J Environ. . Qual. 19:215-233. Ritchie, J.C., J.R. McHenry, and G.B. Bubenzer. 1982. Distribution of fallout Cs-13 n Brunnei 7 r Creek watershe n Wisconsini d . Trans. Wisconsin Acad. Sei., Arts, Lett. 70:161-167.

Ritchie, J.C., J.R. McHenry, and A.C. Gill. 1970. Distribution of cesium-137 in the upper 4 inches of soil in relation to vegetation type. ASB Bulletin 17:60. Ritchie, J.C., J.R. McHenry, and A.C. Gill. 1972a. Dating recent reservoir sediment using radioactive fallout. ASB Bulletin 19:95. Ritchie, J.C., J.R. McHenry, and A.C. Gill. 1972b. The distribution of Cs-137 in litter and the upper 10 centimeters of soil under different vegetation types in northern Mississippi. Health Phys. 22:197-198. Ritchie, J.C., J.R. McHenry, and A.C. Gill. 1972c. Dose rates over reservoir o fallout e du s t Cs-137. Health Phys. 23:406-407.

Ritchie, J.C., J.R. McHenry A.Cd an , . Gill. 1973. Dating recent reservoir sediments. Limnol. Oceanogr. 18:255—264.

Ritchie, J.C., J.R. McHenry, and A.C. Gill. 1974. Fallout Cs-137 in the soils and sediments of three small watersheds. Ecol. 55:887-890. Ritchie, J.C., J.R. McHenry, A.C. Gill, and P.H. Hawks. 1970a. The use of fallout cesium-137 as a tracer of sediment movement and deposition. Mississippi Water Resour. Conf. Proc . 149-163pp . .

Ritchie, J.C., J.R. McHenry, A.C. Gill, and P.H. Hawks. 1970b. Distribution of fallout cesium-137 in sediment profiles. Health Phys. 19:334.

Ritchie, J.C., J.R. McHenry, A.C. Gilld P.Han , . Hawks. 1972. Fallout Cs-137 in reservoir sediments. Health Phys. 22:97-98.

184 Ritchie, J.C., J.R. McHenry, A.C. Gill d P.Han , . Hawks. 1973. Distributio f Cs-13a o smaln n i 7l watershe n northeri d n Mississippi 129-133. ,pp D.J: .In . Nelson (ed.). Proceedings of the third national symposium on radioecology. USAEC CONF- 710501-pl AtomiS ,U c Energy Commission, Washington. ,DC Ritchie, J.C d G.Lan . . Plummer. 1969. Natural gamma radiation i n northeas east-centrad an t l Georgia. Bull. Georgia Acad. Sei. 27:173-194.

Ritchie, J.C., J.A. Spraberry, and J.R. McHenry. 1973. Estimating soil erosion from the redistribution of Cs-137 fallout. Agronomy Abstracts 1973 Annual Meeting 129. ,p . Ritchie, J.C., J.A. Spraberry J.Rd an , . McHenry. 1974. Estimating soil erosion froredistributioe mth f fallouno t Cs-137. Soil Sei. Soc. Am. Proc. 38:137-139. . MarchandiseRobbeP , D. ,. Thomas A d an ,. 1983. Déterminatioe d n l'origine des pollutions métalliques par datation des carottes de sédiments. Bull. Laiso b PontLa n s Chaussées 127:81-92. (French) Robbins, J.A. 1978. Geochemistr d geophysicaan y l applicatiof o n radioactive lead, pp. 285-393. In: J.O. Nriagu (éd.) The Biochemistry of lead in the environment. Elsevier, Amsterdam. Robbins, J.A. 1980. Sediment f southero s n Lake Huron: elemental composition and accumulation rate. USEPA, Ecological Research -Series, EPA-600/3-80-080, August 1980, 309 pp. (Plus Appendix, 198 pp.) Robbins, J.A. 1982. Stratigraphie and dynamic effects of sediment reworkin Greay gb t Lake zoobenthos. Hydrobiologia 92:611-622. Robbins, J.A. 1985a. Great Lakes regional fallout source functions. KOAA Technical Memorandum ERL GLERL-56, Ann Arbor, MI. Robbins, J.A. 1985b e coupleTh . d lake mode r estimatinfo l e th g long-term response Greath tf o eLake o time-dependent s t loadings of particle-associated contaminants. NOAA Technical Memorandum ERL GLERL-57, Ann Arbor, MI. Robbins, J.A. 1986a. Sediment in Saginaw Bay, Lake Huron: elemental composition and accumulation rates. Great Lakes and Marine Waters Center ,e GreaSpeciath tf o Lake l2 Repor10 s . No t Research Division, Univ. Michigan Arborn ,An . ,MI Robbins, J.A. 1986b. A model for particle—selective transport of tracer n sedimeni s t with conveyors belt deposit feeders. .J Geophys. Res. 91:8542-8558. Robbins, J.A., E. Callendar, and N.R. Morehead. 1988. Records of fallout Cs—13 Lakn 7i e Oahe Reservoir South Dakota TransS .EO . 69:68. Robbins, J.A d B.Jan . . Eadie. 1991. Seasonal cyclin f traco g e elements l37Cs, 7 Be239d -|-,an 240Lakn pi u e Michigan . GeophysJ . . Res. 96:17081-17104. Robbins, J.A. and D.N. Edgington. 1972. The use of natural and fallout radionuclide measuro st e recent sedimentation raten si Southern Lake Michigan, pp. 31-53. In: Argonne National Lab. Rep. ANL-7960, ParArgonn, t3. e National Laboratory, Argonne, IL. Robbins, J.A. and D.N. Edgington. 1973. Stable lead geochronology of fine-grained sediment southern si n Lake Michigan . 32-39,pp . In: Radiological and environmental research division annual report, ecology, January-December 1973, Argonne National Laboratory, Argonne, IL. _

185 Robbins, J.A. and D.N. Edgington. 1974. The distribution of trace element clae th y n ssili t sediment Granf so d Haven 78-85. ,pp . In: Radiological and environmental research division annual report, ecology, January-December 1973. Argonne National Laboratory, Argonne, IL. Robbins, J.A. and D.N. Edgington. 1975. Determination of recent sedimentation rate Lakn si e Michigan using Pb-21 Cs-137d 0an . Geochim. Cosmochim. Acta 39:285-304. Robbins, J.A. and D.N. Edgington. 1976. Depositional processes and determination of recent sedimentation rates in Lake Michigan, pp. 378-390. In: Proceedings second federal conference on the Great Lakes Arborn ,An . ,MI Robbins, J.A., D.N. Edgington Gustinis. ,J J.Od ,an . Karttune. 1974. Geochronolog Lakf yo e Michigan sediments: anomalie leadn si - 210 distribution, pp. 40-50. In: Radiological and environmental research division annual report, ecology, January-December 1974. Argonne National Laboratory, Argonne, IL. Robbins, J.A., D.N. Edgington, and L.W. Kemp.' 1977. Comparative lead-210, cesium-137 and pollen geochronologies of recent sediments from Lake Erie and Ontario, pp. 87-92. Im Radiological and environmental research division annual report, ecology, January-December 1976. Argonne National Laboratory, Argonne. ,IL Robbins, J.A., D.N. Edgington d L.Wan , . Kemp. 1978. Comparative

CsPb, and pollen geochronologies of sediments from Lake

137 Ontari210 Eried an o . Quat. Res. 10:256-278. Robbins, J.A., K. Husby-Coupland, and D.S. White. 1984. Precise radiotracer measurements of the rate of sediment reworking by Stylodrilus heringianus and the effects of variable dissolved oxygen concentration. J. Great Lakes Res. 10:335-347. Robbins, J.A. . KeiltyT , , D.S. White D.Nd an , . Edgington. 1989. Relationship among Tubif icid abundances, sediment composition, and accumulation rates in Lake Erie. Can. J. Fish. Aquat. Sei. 46:223-231. Robbins, J.A., J.R. Krezoski, and S.C. Mozley. 1977. Radioactivity in sedimente Greath tf o s Lakes: post-depositional redistributio deposit-feediny nb g organism. Earth Planet. Sei. Lett. 36:325-333. Robbins, J.A., G. Lindner, W. Pfeiffer, J. Kleiner, H.H. Stabel, and P. Frenzel. 1992. Eplimnetic scavenging of Chernobyl radionuclide n Laki s e Constance. Geochim. Cosmochim. Acta 56:2339-2361.

Robbins, J.A., P.L. McCall, J.B. Fisher, and J.R. Krezoski. 1979. Effect of deposit feeders on migration of '37Cs in lake sediment. Earth Planet. Sei. Lett. 42:277-287. Robbins, J.A., A. Murdock, and B.C. Oliver. 1990. Accumulation of fallout cesium-137 and chlorinated organic contaminants in recent sediments of Lake St. Clair. Can. «I. Fish. Ag_uat. Sei. 47:572-587. Robbins, J.A. and C.L. Schelske. 1988. Biogenic silica deposition in Lake Erie since 1800. EOS Trans. 69:1143.

Rogowski, A.S. and T. Tamura. 1965. Movement of l37Cs by runoff, erosio d infiltratioan n e alluviath n no l Captina silt loam. Health Phys. 11:1333-1340. Rogowski, A.S. and T. Tamura. 1970a, Environmental mobility of cesium-137. Radiât. Bot. 10:35-45.

186 Tarnura.. T Rogowski d An ". S 1970b. ,A . Erosional behavio cesiumf o r - 137. Health Phys. 18:467-477. Rose, C.W. , M.E. McCallan, B.M. O'Leary, and G. Sander. 1980. Testing a model of field-scale soil erosion and deposition on a plane land element using the fallout isotope 137Cs. Conferenc agriculturan eo l engineering, Geelong, Australia. Rose, K.A., A.L. Brenkert, G.A. Schohl, Y. Onishi, J.S. Hayworth, F. Holly, W. Perkins, L. Beard, R.B. Cook, and W. Waldrop. 1993. Multiple model analysis of sediment transport and contaminant distribution in the Clinch River Watts Bar Reservoir, Tennessee, USA. Water Sei. Tech. 28:65-78. Rowan, J.S., S.B. Bradley, and D.E. Walling. 1992. Fluvial redistributio Chernobyf o n l fallou - reservoit r evidencn i e the Severn Basin. J. Inst. Water Environ. Manage. 6:659-666. Rowan, J.S., D.L. Higgitt, and D.L. Walling. 1993. Incorporation of Chernobyl-derived radiocaesiu n i reservoim r sedimentary sequences, pp. 55-71. Jn: J. McManus and R. Duck (eds.), Geomorphology and sedimentology of lakes and reservoirs, Wiley, London. Rowan, J.S. and D.E. Walling. 1992, The transport and fluvial redistribution of Chernobyl-derived radiocaesium within the River Wye Basin, OK. Sei. Total Environ. 121:109-131. Rummery, T.A. . ,BloemendalJ . DearingJ , . OldfieldF ,. R d an , Thompson. 1979. The persistence of fire-induced magnetic oxide soiln si lakd san e sediments. Ann. Geophvs. 35:103-107. . SaxénPuhakainen. SaloR M d , ,an A. . 1984. Transpor airbornf to e d 137Can s r deposite e ^S five basinth th e f n o i slargesd t rivers in Finland. Aqua Fennica 14:21-31. . TuomainenK Salo , Voipio. A A. , d ,an . 1986. Inventorie f somo s e long-lived radionuclide e Baltith n i cs Sea. Sei. Total Environ. 54:247-260.

Salt, C.A. and R.W. Mayes. 1991. Seasonal variations in radiocaesium uptake by reseeded hill pasture grazed at different intensities by sheep. J. Appl. Ecol. 28:947-962. Salt, C.A. and R.W. Mayes. 1993. Plant uptake of radiocaesium on heather moorland graze sheepy db Appl. .J . Ecol. 30:235-246. Salt, C.A., R.W. Mayes, and O.A. Elston. 1992. Effects of season, grazing intensit d diean yt compositio e radiocaesiuth n o n m intak y sheeb e n reseedeo p d hill pasture . Appl.J . Ecol. 29:378-387. Sanders K.C, ,G. . Jones Hamilton. ,J Dörr. H d .,an 1992. Historical input of polychlorinated-biphenyls and other organochlorides datea o t d lacustrine sediment cor ruran ei l England. Environ. Sei. Tech. 26:1815-1821. Sandman, O., A. Lichu, and H. Simola. 1990. Drainage ditch erosion histor recordes a yvarvee th n ddi sedimen smala f to l lakn ei East Finland. J. Paleolianology 3:161-169. Santschi, P. 1984a. Particle flux and trace metal residence times in natural waters. Limnol. Oceanogr. 29:1100-1108. Santschi . 1984b,P . Radionuclide tracers sa r sedimentatiofo s d an n remobilization processe lakesn i oceae . 437d th ,pp an nn si - 449. Im P.G. Sly (ed.), Sediment and water interactions, Springer-Verlag, London.

187 Santschi, P.H. 1987. Chernobyl radionuclide e environmentth n i s : e tighth tracer r t fo scouplin g between atmospheric, terrestria d aquatian l c geochemical processes. EAWAG News 22/23:1-6. Santschi, P.H. f o radionuclide1989 e e Us .studth f o n yi s contaminant cycling processes. Hydrobiologia 176/177:307-320. Santschi, P.H.Bollhalder. S , Farrenkothen. ,K Lueck. ,A Zingg. ,S , . anM Strumd . 1988. Chernobyl radionuclidee th n i s environment: tracers for the tight coupling between atmospheric, terrestrial aquatid ,an c geochemical processes. Environ. Sei. Tech. 22:510-516.

Santschi, P.H., S. Bollhalder, S. Zingg, A. Lueck, and K. Farrenkothen. 1990 e self-cleaninTh . g capacit f surfaco y e waters after radioactive fallout. Evidence from European waters after Chernobyl. Environ. Sei. Tech. 24:519-527. Santschi, P.H B.Dd an . Honeyman. 1989. Radionuclide aquatin i s c environments. Radiât. Phys. Chem. 34:213-240.

Santschi, P.H., Y.H , D.MLi . . Adler . AmdurerM , . BellJ , , U.P. Nyffeler. relative 1983Th . e mobilit naturaf yo ) Po l , (ThPb , and fallout (Pu, Am, Cs) radionuclides in the coastal marine environments: results from model ecosystems (MERLd an ) Narragansett Bay. Geochim. Cosnochim. Acta 47:201-210.

Santschi, P.M. . CarsonS ,d an Y.H. , 1980Li . e fat Th f .traco e e metals in Narragansett Bay, Rhode Island: radiotracer experiment n microcosmsi s . Estuar. Coast. Marine Sei. 10:635-654. Santschr; P.H. . O'Hara,P , Y.H Li Amdurer. .,M . . AdlerP D , d an , Doering. 1987. The relative mobility of radioactive trace elements acros sediment-watee sth r interfac MERe th L f modeeo l ecosyste Naragansetf mo t MarinBay. J . e Res. 45:1007-1048.

Santschi, P.H. Nixon. ,S Pilson. ,M Hunt . C d .,an 1984. Accumulation' of sediment, trace metals {Pb, Cu) and hydrocarbons in Narragansett Bay, Rhode Island. Estuar. Coast. Shelf. Sei. 19:427-450. Santschi, P.H. , U.P. Nyffeler, R.F. Anderson, S.L. Schiff, and P. O'Hara. 1986. Response of radioactive trace metals to acid-base titratio n controllei n d experimental ecosystems: evaluatio transporf o n t parameter r applicatiofo s o wholt n e lake experiments. Can. J. Fish., Aquat. Sei. 43:60-77. Santschi, P.H. and P.W. Schindler. 1977. Chemical and geochemical studies of Lake Biel. I. A mass balance for Lake Biel and its implications for the rates of erosion in the drainage area. J. Hydrol. 39:181-200. Santschi, P.H., C. Schuler, and M. Strum. 1987. Natural and Chernobyl radionuclides as tracers of particle settling and resuspension in Lake Zurich, Switzerland. Terra Cognita 7:185. Santschi, P.H.Schuler. C , Strum. ,M Lueck. ,A Farrenkothen. ,K . ,S Bollhalder, and E. Wieland. 1988. Natural radionuclides in Lake Zurich: tracer particlr sfo traced ean r element dynamics. EOS Trans. 69:1085. Sawhney, B.L. 1964. Sorptio cesiuf no m from dilute solutions. Soil Sei. Soc Proc. .Am . 28:25-28. Sawhney, B.L. 1966. Kinetics of cesium sorption by clay minerals. Soil Sei. Soc Proc. .Am . 30:565-569, Sawhney, B.L. 1972. Selective sorptio d fixationan f cationno y sb clay minerals: a review. Clays and Clay Minerals 20:93-100.

188 Sbrignadello Degetto. S , ,G. , G.A. Battiston Gerbasi. R d ,an . 1994. Distribution of Pb-210 and Cs-137 in snow and soil samples from Antarctica. Internat. J. Environ. Analyt. Chem. 55:235-242. Schimmack Bunzl. K d an . 1992a. ,W . Migratio radiocesiuf no o tw n i m forest soil obtaines sa d from fiel columd dan n investigations. Sei. Total Environ. 116:93-107.

Schimmack, W. and K. Bunzl. 1992b. Transport of ^Sr,œ Co, "Zn and o forestw l(Wn Cti d soils s observea , n undisturbei d d soil columns. Radiochim. Acta 58/59:297-303.

Schimmack BunzlBachhuber. . K H , d . ,an W . 1993. Variabilite th f yo t traca I e d an , Te , Ru , Ce , Cd , Co , Sr , Zn sorptio , Cs f no concentrations by a forest soil along a transect. Environ. Internat. (In Press). Schimmack, W., K. Bunzl, F. Dietl and D. Klotz. 1994. Infiltration of radionuclides witw mobilitlo h y ( D7wd CCosan ) inta o forest soil. Effec f irrigatioo t n intensity . EnvironJ . . Radioact. 24:53-63. Schimmack, W., K. Bunzl, and L. Zelles. 1989. Initial rates of migration of radionuclides from the Chernobyl fallout in undisturbed soils. Geoderma 44:211-218. Schimmack, W., H. Foerster, K. Bunzl, and K. Kreutzer. 1993. Depositio radiocesiuf no soie stemfloy th l b o mt w through fall and leaf-fall from beech trees. Radiât. Environ. Biophys. 32:137-150. Schlesinger, W.H., P.J. Fonteyn W.Ad ,an . Reiners. 1989. Effectf so overland flo n plano w t water relations, erosion d soian , l water percolatio Mojava n no e Desert landscape. Soil Sei. Soc. Am. J. 53:1567-1572. Schoenburg 1987. ,M . Radiometrie datin quantitativd gan e analysif so elements in depth profiles of sediments by means of nuclear physica wels la s x-ra a l y fluorescenc d atomian e c emission spectroscopic methods. Fachbereich 12-Physik., Rep. GKSS- 87/E/54, Hamburg Univ., Germany. (-German) Schoer, J. 1988. Investigation of transport processes along the Elbe River using Chernobyl radionuclides as tracers. Environ. Tech. Lett. 9:317-324. Schreiber . 1967aB , . Ecolog f Acanthario y n relatioi ar S f o n circulation in the sea. Final Report Contract US/62, International Atomic Energy Agency, Vienna, Austria. Schreiber 1967b. ,B . Radionuclide marinn si e plankto coastan i d nan l sediments, pp. 753-770. In: B. Aberg and F.P. Hungate (eds.) Radioecological concentration processes, Pergamon Press, London. Schreiber . 1968B , . Essamethoda f o y f absolut,o e e datinth f o g coastal marine sediment vertica e meany sth b f so l distribution of the fallout radionuclides. Accademia Nazionale Dei Lincei 45:251-257. Schreiber . 1969B , . Significanc f sedimento e n evaluatini s e th g radioactive contaminatio seae th .f no Fourt h Internat. Colloq. Medical Oceanography, Naples, Italy, October 1969. Schreiber, B. 1974. Plankton and sediment: first and last step of e radioactivitth y diffusio e areath .n i nCienci e Cultura a 27:197-206.

189 Schreiber, B., E. Cerrai, C. Triulzi, L.T. Pelati, and M.G. Mezzadri. 1969. Ricerche sulla distribuzione verticale délia radioattivita nei sedimenti del Mar Ligure. Giornale di Fisica Sanitari Protezionae e Contre Radiazione »l i 13:1-19. (Italian)

Schreiber L.T, ,B. . Pelati Cerrai. Triulzi,. E C d ,an . 1964. Gross beta radioactivity of littoral sediments of the Ligurian Sea. Energ. Nucl. (Milan) 11:616-624. Schreiber L.T, ,B. . Pelati, M.G. Mezzadri Motta. G d ,.an 1968. Gross beta radioactivity in sediments of the North Adriatic Sea: a possibilit f evaluatino y e sedimentatioth g n rate. Arch. Oceanogr. Limnol. 16:45-62. Schroeder, R.A. 1985. Sediment accumulation rate n Irondequoii s t Bay, New York based on lead-210 and cesium-137 chronology. Northeastern Environ. Sei. 1:23-29. Schuler, C., E. Wieland, P.H. Santschi, M. Sturm, A. Lueck, S. Bollhalder, J. Beer, G. Bonani, H.J. Hofmann, M. Suter, and W. Wolfi. 1991. A multitracer study of radionuclides in Lake Zurich, Switzerlan . I Comparisod f o atmospherin d an c sedimentary fluxes of 7Be, 10Be, 2l°Pb, 210Po, and l37Cs. J. Geophys. Res. 96:17051-170965. Schultz, R.K. 1965. Soil chemistr radionuclidesf o y . Health Phys. 11:1317-1324. Schultz, R.K., R. Overstreet, and I. Barshad. 1960. On the soil chemistr cesium-137f yo . Soil Sei. 89:19-27. Shand, C.A., M.V. Cheshire, S. Smith, M. Vidai and G. Rauret. 1994. Distribution of radiocesium in organic soils. J. Environ. Radioact. 23:285-302. Sharma, P., L.R. Gardner, W.S. Moore, and M.S. Bollinger. 1987. Sedimentatio bioturbatiod nan sala n tni mars reveales ha y db 210 Pbstudiese B ,7 137d Can s . Limnol. Oceanogr. 32:313-326. Shenber, M.A. and A. Eriksson. 1993a. Sorption behavior of caesium in various soils. J. Environ. Radioact. 19:41-51. Shenber, Eriksson. M.AA d .an . 1993b. Exchangebilit f caesiuyo n mu various soils. Sei. Total Environ. 138:271-279. Sholkovitz, E.R. 1985. Redox-related geochemistr lakesn i y : alkali metals, alkaline-earth elements, and 137Cs, pp. 119-142. In: W. Strumm (ed.), Chemical processes in lakes, Wiley, New York. Sholkovitz, E.R., J.K. Cochran, and A.E. Carey. 1983. Laboratory studiee digenesith f o s mobilitd an s n9f -o y 2 d l37*Pn Can ui s nearshore sediments. Geochi*. Cosmochim. Acta 47:1369—1379. Sholkovitz, E.R D.Rd .an . Mann. 1984 pore .Th e water chemistr- a9 f yo ^Pu and l37Cs in sediments of Buzzards Bay, Massachusetts. Geochim. Cosmochim. Acta 48:1107-1114. Shutov, V.N., T.A. Bekyasheva, L.N. Basalaeva, G.Y. Bruk, and I.Y. pavlov. 1993. Influenc soif eo l propertie cesium-13n so d 7an strontium-90 radionuclides uptake by natural grasses. Pochvovedeniye 8:67-71. (Russian) Sibley, T.H., A.L. Sanchez, E.A. Wurtz, and W.R. Schell. 1982. Distribution coefficients for radionuclides in aquatic environments. U.S. Nuclear Reg. Comm., MUREG/CR-18S3.4, 52 pp.

. Kistler. StrumD M Sigg d , an ,L. , . 1987. Vertical transporf o t heavy metals by setting particles in Lake Zurich. Limnol. Oceanogr. 32:112-130.

190 Simpson, H.J., R.F. Bopp, B.L. Deck, and R.J. Larsen. 1986. Regional accumulation amounts per unit area of persistent pollutants derived from analysi f receno s t sediments. Mem. Soc. Geol. Ital. 27:423-445. Simpson, H.J., C.R. Olsen, R. Bopp, R.M. Trier, and S.C. Williams. 1978. Cesium-137 as a tracer for reactive pollutants in- estuarine sediments. First American-Soviet Symposium on Chemical Pollution of Marine Environment, EPA-600/9-78-038, EPA, Gulf Breeze, FL. Simpson, H.J., C.R. Olsen, R.M. Trier, and S.C. Williams. 1976. Man-made radionuclides and sedimentation in the Hudson river estuary. Sei. 194:179-183. Simpson, H.J.-, R.M. Trier d C.Ran , . Olson. 1980. Transporf o t plutoniu y riversb m . 684—690pp , W.C: In .. Hanson (ed.), Transuranics elements in the environment. US Department of Energy, Washington. ,DC Simpson, H.J., S.C. Williams, C.R. Olsen, and D.E. Hammond. 1977. Nutrient and particle matter budgets in urban estuary, pp. 94-103 m I Estuaries. , geophysic e environmentth d an s , National Academy of Science, Washington, DC. Singh, B. and R.J. Gilkes. 1990. Sorption-desorption behavior of caesium in some Western Australian Soils. Aust. J. Soil Res. 28:929-946. . NeretnieksI Skagius d an . K ,. 1988. Measurement f cesiuo s d an m strontium diffusion in biotite gneiss. Water Resour. Res. 24:75-84. Smith, C.J., R.D. DeLaune, and W.H. Patrick Jr. 1983. Carbon dioxide emissions and carbon accumulation in coastal wetlands. Estuar. Coast. Shelf Sei. 17:21-29. Smith, J.N. and K.M. Ellis. 1982. Transport mechanism for Pb-210, Cs-137 and Pu fallout radionuclides through fluvial-marine systems. Geochim. Cosmochim. Acta 46:941-954. Smith, J.N. and K.M. Ellis. 1988. Transport mechanism for fallout o 137t estuarinCs e sediments. SM-248 . pp 119-130, , International Atomic Energy Agency, Vienna, Austria. Smith, J.N., K.M. Ellis, and D.M. Nelson. 1987. Time-dependent modeling of fallout radionuclide transport in drainage basin: significanc f "slowo e " erosiona d "fastan l " hydrological components. Chem. Geol. 63:157-180. Smith, J.N. and C.T. Schafer. 1987. A 20th-century record of climatologically modulated sediment accumulation rates in a Canadian fjord. Quat. Res. 27:232-247.

Smith ,. Walton A J.N d .an . 1980. Sediment accumulation rated an s geochronologies measured in the Saguenay Fjord using Pb-210 dating method. Geochim. Cosmochim. Acta 44:225-240. Smith, M.L., H.W. Taylor, and H-D. Sharma. 1993. Comparison of the post-Chernobyl Cs-137 contamination of mushrooms from Eastern Europe, Sweden Nortd ,an h America. Appl. Environ. Microbiol. 59:134-139. Smith, R.A., R.B. Alexander M.Gd ,an . Wolman. 1987. Water-quality trendnation'e th n si s rivers. Sei. 235:1607-1615. Smith, S.J., J.R. McHenry, R.G. Menzel, and N.H. Welsh. 1986. Agricultural chemical heavd san y metal uplann si d soild an s valley alluviums of the Little Washita River basin. J. Soil Water Conserv. 41:333-336.

191 Smolders, E.f L. Sweeck, J. Buysse, K. Van den Brande, and R. Merckx. 1993. e Analysigenotypith f o s c variation i n radiocaesium uptake from soil. Plant and Soil 155/156:431-434. Sobocinski, R.W., T.E. Cerling S.Jd an , . Morrison. 1990. Sediment transport in a small stream based on 137Cs inventories of the bed load fraction. Water Resour. Res. 26:1177-1187. Sobotovich, E.V. 1992. Geochemistry of radionuclides in the region Chernobye oth f l NPP 170-175. ,pp : Scientifi.In c conference n problemo f Chernobylo s , Kiev, Ukraine, Dokl. Akad. Naul. UKR. (Russian) Soileau, J.M., B.F. Hajek, and J.T. Touchton. 1990. Soil erosion and deposition evidence in a small watershed using fallout cesium- 137. Soil Sei. 54:1712-1719. SocJ . .Am . Soszka, G.J . GrzybowskaD . . RostekJ , . PietruszewskiA , . T , Wardaszko, A. Kalinowska, and J. Tomczak. 1986. IX Radioecological characteristic Lakf so e Zarnowieckie. Polish Ecological Studies 12:363-381. Southard, R.E R.Cd .an . Graham. 1992. Cesium-137 distributioa n i n California Pelloxerert: evidence of pedoturbation. Soil Sei. Soc. Am. J. 56:202-207. Spalding, B.P. 1994. Volatilization of cesium-137 from soil with chloride amendments during heatin vitrificationd gan . Environ. Sei. Tech. 28:1116-1123. Spezzano, P., s. Bortoluzzi, R. Giacomelli, and L. Massironi. 1994. Seasonal variation Cs-13f so 7 activitie e Dorth an i sBalte a River (Northwest Italy) afte e Chernobyth r l accident. J . Environ. Radioact. 22:77-88. Spezzano Hilton. J , ,P. , J.P. Lishman T.Rd ,an . Carrick. 1993e .Th variability of Chernobyl Cs retention in the water column of Englise laketh n i sh Lake Distric o year ttw d fou san r years after deposition. J. Environ. Radioact. 19:213-232. Sportier, R.G., J.R. McHenry, and R.F. Piest. 1985. Sediment movement and deposition using cesium-137 tracer. Trans. Am. Soc. Agric. Engr. 28:767-772.

Spraberry, J.A. and A.J. Bowie. 1969. Predicting sediment yield from complex watersheds. Trans Soc. .Am . Agric. Engr. 12:199-201. Spurgel, D.G. and G.E. Bartelt. 1978. Erosional removal of fallout plutonium from a large midwestern watershed. «J. Environ. Qual. 7:175-177. Squire, H.M. and L.J. Middleton. 1966. Behavior of l37Cs in soils and pasture lona s- g term experiment. Radiât. Bot. 6:413-423. Stanners, D.A d S.Ran . . Aston. 1981a n improveA . d methor fo d determining sedimentation rates by use of artificial radionuclides. Estuar. Coast. Shelf Sei. 13:101-106.

Stanners, D.A. and S.R. Aston. 1981bCCss ,.and "*Ru:C 's ratios

137 37 in intertidal sediments froml34 the Cumbria and Lancashire Coasts, England. Estuar. Coast. Shelf Sei. 13:409-417. Stanners, D.A d S.Ran . . Aston. 1981c. Factors controlline th g interactio Cs-13f no 7 with suspende deposited dan d sediments in estuarine and coastal environments, pp. 131-141. In: Impact radionuclidf o s e release marine th o st e environment, International Atomic Energy Agency, Vienna, Austria.

192 Stanners, D.A. and S.R. Aston. 1982. Desorption of Ru-106, Cs-134, Cs-137 and Am-241 from intertidal sediments contaminated by nuclear fuel reprocessing effluents. Estuar. Coastal Shelf Sei. 14:687-692. Stanners, D.A d S.Ran .. Aston f reprocessino . e 1984us e .Th g effluent radionuclides e geochronologth n i . f o receny t sediments. Cheat. Geol. 44:19-32. Steenbergen, C.L.M., G.W. Berger, H.J. Korthals Verdouw. H d an , . 1989. Pigment stratigraphy and trophic status: an evaluation of radionuclide-dated lacustrine sediment. Geomicrobiolog. yJ 7:207-222. Steinberg, C., E. Hammerle, and J. Meihamm. 1983. Changes in sedimentary fluxe n Laki s e Walchense y anthropogenicallb e y caused alterations in its catchment area. Z. Wasser A.B. 16:48-54. . NjastadSteinnesD d an .. E ,f mosse1993 o d e lichenan sUs . r fo s regional mappin l37f go C s fallout froChernobye mth l accident. J. Environ. Radioact. 21:65-73. Stewart, W.D.P. Preston. ,T , H.G. Peterson Christofi. N d ,an . 1982. Nitrogen cyclin eutrophin gi c freshwaters. Phil. Trans. Royal Soc. Londo 296:491-509nB . Stihler, S.D., D.B. Stone J.Ed ,an . Beget. 1992. Varve countins gv tephrochronology and Cs-137 and Pb-210 dating - A comparative test at Skilok Lake, Alaska. Geology 20:1019-1022. Stiller, M. 1979. Sedimentation patterns in Lake Kinneret (Tiberias) . 273-285pp , : IsotopeIn . n laki s e studies, Advisory Group Meeting, 29 Aug. - 2 Sept. 1977, International Atomic Energy Agency, Vienna, Austria.

. AssafG Stiller d .an 1973. M , . Sedimentatio d transporan n f o t

particles in Lake Kinneret traced Csby. IAHS Publ. No. 109:383-396. I37 Stiller D.Md an .. , ImbodenM , 1986. 2l Lak°Pn i b e Kinneret waterd san sediments: residence times and fluxes, pp. 501-511. In: P.G. Sly, (ed.), Sediment and water interactions, Springer-Verlag, New York. Stiller, M., N.E. Yanaki, and J. Kronfeld. 1985. Comparative isotope study of two short sediment cores from the Dead Sea. Chera. Geol. 58:107-109. Stott, A.P. 1987. Medium-term effects of afforestation on sediment dynamics in a water supply catchment: a mineral magnetic interpretation of reservoir deposits in the Macclesfield Forest, N.W. England. Earth Surf. Processes Landforms 12:619- 630, Stow, C.A., R.D. DeLaune, and W.H. Patrick Jr. 1985. Nutrient fluxes in a eutrophic coastal Louisiana freshwater lake. Environ. Manage. 9:243-252. Strandberg, M. and H. Knudsen. 1994. Mushroom spores and Cs-137 in deere ro Environ. .J e faece th f so . Radioact. 23:189-203. Sugai, S.F. 1990. Transpor d sedimenan t t accumulatio 2ld f °Po nan b southeaso tw l37 n Ci s t Alaskan fjords. Estuar. 4:380-392. Seff. K , ,T. N.B, .Sun Heo V.Pd ,an . Petranovskii. 1993 cationi.A c cesium continuu Zeolite-Xn mi . Sei. 259:495-497. Sutherland, R.A. 1989. Quantification of accelerated soil erosion using the environmental tracer caesium-137. Land Degradation and Rehabilitation 1:199-208.

193 Sutherland, R.A. 1991a. Examinatio caesium-13f no 7 areal activities in control (uneroded) locations. Soil Tech. 4:33-50. Sutherland, R.A. 1991b. Caesium-13 sedimend 7an t budgeting withina partiality closed drainage basin. Ann. Geonorphol. 35:47-63. Sutherland, R.A. 1991c. Selective erosion and sediment source identification, Baringo, Kenya. Ann. Geomorphol. 35:293-304. Sutherland, R.A. 1992. Caesium-137 estimate f o erosios n i n agricultural areas. Hydrol. Processes 6:215-225. Sutherland, R.A. 1994. Spatial variability of l37Cs and the influence of samplin estimaten go f sedimenso t redistribution. Catena 21:57-71. Sutherland, R.A. and R.B. Bryan. 1988. Estimation of colluvial reservoir life from sediment budgeting, Katiorin experimental basin, Kenya. IAHS Publ 174:549-560. .no . Sutherland, R.A. and R.B. Bryan. 1991. Sediment budgeting - a case stud Katioren yi n drainage basin, Kenya. Earth Surf. Processes Landforms. 16:383-398.

Sutherland e Jongd , . -E R.A d 1990aan . . Estimatio f sedimeno n t redistribution within agricultural fields using caesium-137. Crystal Springs, Saskatchewan, Canada. Appl. Geography 10:205- 221. Sutherland e Jongd , . R.A.E d 1990bTan . Quantificatio f soio n l redistribution using caesium-137, Saskatchewan, Canada, pp. 177-193. Im R.B. Bryan (ed.). Soil erosion - experiments and models. Catena Supplement 17. Sutherland e Jongd , . R.AE . d 1990c.an . Statistical analysi- f o s gamma emitting radionuclide concentrations for three fields, Southern Saskatchewan, Canada. Health Phys. 58:417-428. Sutherland, R.A., T. Kowalchuk, and E. de Jong. 1991. Cesium-137 estimate f sedimeno s t redistributio y windb n . Soil Sei. 151:387-396. Suzuki . 1993E . . ''"B 137d nearshorn iCi an s e marine sediments. I . Distribution of ^Bi and 137Cs in coastal marine sediments collected froJapae mth n Sea. Radioisotopes 42:511-516. Svoboda, J. and H.W. Taylor. 1979, Persistence of cesium-137 in Arctic lichens, Dryas integrifolia, and lake sediment. Arct. Alp. Res. 11:95-108. Swan, D.S., M.S. Baxter, I.G. KcKinley . JackW d . an ,1982 . Radiocesium and 210Pb in Clyde Sea Loch sediment. Estuar. Coast. Shelf Sei. 15:515-536. Sweeeck, L., J. Wauters, E. Valcke, and A. Cremers. 1990. The sensitivity of upland soils to radiocesium contamination, pp. 249-258 Desment. G : .In Nassimbeni. ,P Bell. M d i, an (eds.) . Transfe f o radionuclider n naturai s d semi-naturaan l l environments, Proceeding workshopC CE a f so , Udine, Italy. Talibudeen . 1964O , . Natural radioactivit n soilsi y . Soils Pert. 27:347-359. Tamura . 1964aT , . Consequence f activito s y release: selective sorption reactions of cesium with soil minerals. Nucl. Safety 5:262-268. Tamura T. 1964b. Reaction of cesium-137 and strontium-90 with soil minerals and sesguioxides, pp. 465-478. In: 8th. International congres soif so l science, Bucharest, Romania.

194 Tamura, T. and D.G. Jacobs. 1960. Structural implications in césium sorption. Health Phys. 2:391-398. Teksoz, G.V. Yetis . TuncelG , T.Id an ,. Balkas. 1991, Pollution chronologie Goldef so n Horn sediments. Marine Pollut. Bull. 22:447-451. Thiry, Y. and C. Myttenaere. 1993. Behavior of radiocaesium in forest raultilayered soils. J. Environ. Radioact. 18:247-257. Thomas, M., D. Petit, and L. Lamberts. 1984. Pond sédiment as historical recor f heavo d y metals fallout. Wate r SoiAi rl Pollut. 23:51-59.

Thorbjarnarson, K.W., C.A. Nittrouer, and D.J. DeMaster. 1986. Accumulation of modern sediment in Quinault Submarine Canyon. Marine Geol. 71:107-124. Tikhomirov, F.A., A.L. Klyashtorin d A.Ian , . Shcheglov. 1992. Radionuclide n verticai s l soil runof n foresi f t neae th r Chernobyl'nuclear power station. Eurasian Soil Sei. 24:42-49. Tomlin, A.D., D. McCabe, and R. Protz. 1992. Species composition and seasonal variatio f earthwormo n d theian s r effec n soio t l propertie southern i s n Ontario, Canada. Soil Biol. Biochem. 24:1451-1457. Torgersen , A.RT. , . Chivas. ChapmanA d an , . 1983. Chemicad an l isotopic characterization and sedimentation rates in Princess Charlotte Bay, Queensland Aust. .J . Geol. Geophys. 8:191-200. Torgersen, T. and M.E. Longmore. 1984. 137Cs diffusion in the highly organic sedimen f Hiddeo t n Lake, Fraser Island, Queensland. Aust. J. Marine Freshwater Res. 35:537-548. Tracy, B.L F.Ad .an . Prantl. 1983 year5 .2 fissiof so n product input Lakeo t s Superio Hurond ran . Wate Soir rAi l Pollut. 19": 15-27. Turner, A., G.E. Millward, and A.O. Tyler. 1994. The distribution and chemical compositio particlef no macrotidaa n si l estuary. Estuar. Shelf Sei. 38:1-17. Turner, R.R. and S.E. Lindberg. 1978. Behavior and transport of mercur n river—reservoii y r systems downstrea f inactivo m e chloralkali plant. Environ. Sei. Tech. 12:918-923. UNESCO. 1993. Hydrological considerations in relation to nuclear power plants, Proceeding of an International Workshop, UNESCO, Paris. Vakulovsky, S.M., Ï.V. Krasnopevtsev, A.I. Nikitin d V.Ban , . Chumicev. 1982. Distributio r betweeS w l37d f nCwateo e san nth r and bottom sediment e Blac a th USSn Se k1977i n Ri s . Okeanologiya 22:966-969. (Russian) Vakulovsky, S.M., A.I. Nikitin, and V.B. Chumicev. 1983. Cs and n bottoi ""sr m sediment e Baltith f co s Sea. Okeanologiya 137 23:984-989. (Russian) Vakulovsky, S.M., A.I. Nikitin, V.B. Chumichev, I.Y. Katrich, O.A. Voitsekhovich, V.I. Medinets, V.V. Pisarev, L.A. Bovkum, and E.S. Khersonsky. 1994. Cesium-137 and strontium-90 contamination of water bodies in the areas affected by releases from the Chernobyl Nuclear Power Plant accident - An overview Environ. .J . Radioact. 23:103-122. Vande nGulinck. H Berghe d an . .,I 1987. Fallout trace a 137 s Csr a rfo soil mobilit e landscapth n i y e framewor f Belgiao k n loamy region. Pédologie 37:5-20.

195 Van Sickle, J,, W.C. Weimer, and O.P. Larsen. 1983. Mixing rates in

Shagawa Lake, Minnesota sediment s determinea s d froRum profiles. Geochin. Cosmochim. Acta 47:2189-2197. 106

Varskog, P., R. Naeumann, and E. Steinnes. 1994. Mobility and plant availabilit radioactivf yo naturan i s eC l soi relation i l o nt stable Cs, other alkali elements and soil fertility. J. Environ. Radioact. 22:45-53. Vas Carreiro, M.C. and M.M. Sequeria~ 1987. Cesium-137 in the Portuguese Rivers Douro and Tejo. J. Environ. Radioact. 5:363-377. Velasco, R.H., M. Belli, U. Sansone, and S. Menegon. 1993. Vertical transport of radiocesium in surface soils: model implementatio dose-ratd nan e computations. Health Phys. 64:37- 44. Baveye. VerbürgP d an . . 1994,K . Hysteresi binare th n syi exchange of cations on 2/1 clay minerals - A critical review. Clays and Clay Minerals 42:207-220. Vernet, «J.P., E. Davaud, M. Cosandey, and J. Berlie. 1987. Analyse de la radioactivité gamma des sediments del Lac Lerman et de Morat. Ecol. Geol. Helv. 68:87-96. (French) Vernet, J.P., J. Dominik, and P.Y. Favarger. 1984. Texture and sedimentation rates in Lake Geneva. Environ. Geol. 5:143-149. Vernet, J.P. and P.Y. Favarger. 1982. Climatic and anthropogenic effect n sedimentatioo s geochemistrd an n Lakef o y s Bourget, Annecy, and Leman. Hydrobiologia 92:643-650. Vernet, J.P., P.Y. Favarger, and C. Reynuad. 1978. Sedimentation rates in Lakes Morat, Joux, and Leman computed by means of both 137Cs and pollen-analysis methods. Intercol, Second Intl. Congres Ecologyf so , Jerusalem, Israel. Villar, H.P. 1981. Distribuicäo de l37Cs no solo como fumcäo de erosäo e outros processos. Centre de Energia Nuclear, Report No. INIS-MF-7374, 115 pp. (Portuguese) Villar, H.P. 1982. Aplicacoes da distribuicao de 137Cs no estudo da agentes fisicos do solo. IKIS-BR-133, 6 pp. (Portuguese) Voitsekhovitch, O.V., V.V. Kanivets, G.V. Laptev, and I.Y. Biley. 1993. Hydrological processes and their influence on radionuclide behaviour and transport by surface water pathways as applie wateo dt r protection afte Chernobye rth l accident, . 83-105pp . I/a: Hydrological consideration n relatioi s o t n nuclear power plants, Proceedin Internationan a f go l Workshop, UNESCO, Paris. Volchok, H.L. and N. Chieco (ed.). 1986. A compendium of the Environmental Measurement Laboratory's research projects related to Chernobyl nuclear accident. USDOE Rep. EML-460, Environmental Monitoring Laboratory, New York. Von Damm, K.L., L.K. Benninger, and K.K. Turekian. 1979. The °Pb chronolog cora f eyo from Mirror Lak Hampshirew eNe . Limnol. 2l Oceanogr. 24:434-439.

von Gunten, H.R., M. Strum, H.N. Erten, E. Rössler, and F. Wegmüller. 1987. Sedimentation rates in the central Lake

Constance determineCsd. witd SchweizPan bh . HydrolZ . . l37

49:275-283. 210

196 Voronov, S.I. and R.M. Aleksakhi. 1992. Main laws governing the migration of Sr-90 and Cs-137 in natural and cultured framing centers in Uzbekistan (The radioecology of the Tashkent Oasis). Atom. Energy 73:652-657. Gutern n Krahenbuhl. vo U Waber. d H ,an , ,U. . 1987 impace e .Th th f to ChernobyJ. accident on a river/groundwater aquifer. Radiochima Acta 41:191-199. Wahlen R.Cd an .. Thompson,M . 1980. Pollution records from sediments of three lakes in New York state. Geochim. Cosmochim. Acta 44:333-339. Wahlgren, H.A. and D.M. Nelson. 1975. Plutonium in the Laurentian Great Lakes: comparison of surface waters. Verh. Internat. Verein. Limnol. 19:317-322. Walker, R. , M. Wilder, and C.R. Valeri. 1978. Diatom and pollen studie a sedimen f o s t profile from Melynllyn a mountai, n tarnin Snowdonea, North Wales Phytolw .Ne . 8:791. Wallace , E.M,A. . Romney R.Ad an , . Wood. 1982 e rol .f Th stabl o e e cesium on plant uptake of cesium-137. Soil Sei. 134:71-75. Wallbrink, P.J. 1989. Fallout of cosmogenic radionuclide 7Be and its subsequent distributio e soith l n i profilen . 30-89pp , . Honours Thesis, Australian National Univ., Forestry Department, Australia. Wallbrink, P.J A.Sd .an . Murray. 1993f fallouo e .Us t radionuclide as indicators of erosion processes. Hydrol. Processes 7:297- 304. Walling, D.E. 1983. The sediment delivery problem. J. Hydrol. 65:209-237. Walling, D.E. 1984. Sediment delivery from drainage basins1 7 . ,pp 80. In: R.J. Loughran (ed.), Drainage basin erosion anc> sedimentation, Univ. Newcastle, Newcastle, Australia. Walling, D.E. 1988. Measuring sediment yield from river basins, pp. 39-73. In: R. Lal (ed.), Soil erosion research, Soil Conserv. Society of America, Ankeny, IA. Walling, D.E. 1989. The struggle against water erosion and a perspectiv recenn eo t research 39-60. . IvanoK ,pp : d .In an v D. Pechinov (eds.), Water erosion, UNESCO Technical Document in Hydrology, SC-89/WS-57, UNESCO, Paris, France. Walling, D.E S.Bd .an . Bradley. 1988a. Transpor redistributiod tan n of Chernobyl fallout radionuclide fluviay sb l processes: some preliminary evidence. Environ. Geochem. Health 10:35-39.

Walling, D.E. and S.B. Bradley. 1988b. The use of caesium-137 measurement investigato st e sediment delivery from cultivated area Devonn i s IAH. ,UK S Publ . 174:325-335.No . Walling, D.E. and S.B. Bradley. 1989. Rates and patterns of contemporary floodplain sedimentation: a case study of the River Culm, Devon, U.K. Geojouraal 19:53-62. Walling, D.E S.Bd .an . Bradley. 1990. Some application caesiumf so - 137 measurements in the study of fluvial erosion, transport and deposition. IAHS Publ. No. 189:179-203. Walling, D.E., S.B. Bradley, and C.J. Lambert. 1986. Conveyance losse suspendef so d sediment withi nflooa d plain system. IAHS Publ 159:119-131. .No .

197 Walling, D.E., S.B. Bradley, and C.J. Wilkinson. 1986. A caesium-137 budget approach to the investigation of sediment delivery from a small agricultural drainage basin in devon, UK. IAHS Publ. No. 159:423-435. Walling, D.E. and O.P. He. 1992. Interpretation of cesium-137 profile " in lacustrine and other sediments - The role of catchment derived inputs, Hvdrobiologia 235:219-230. Walling, D.E. and Q. He. 1992. Interpretation of caesium-137 profile in lake sediments. In: J. McManus and R. Duck (eds.), Geomorphology and sedimentology of lakes and reservoirs, Wiley, Chichester. Walling cesium-13. f 1993o He e ,. .Us Q D.E tracea e d s th .an 7a n ri stud ratef yo pattern d san floodplaif so n sedimentation. IAHS Publ. No. 215:319-328. Walling ,Kane. P D.E d . an .1984 . Suspended sediment propertied san geomorphological significance . 311-334,pp T.P: .In . Burd tan D.E. Walling (eds.), Catchment experiment n i fluvias l geomorphology Bookso ,Ge , Norwich, U.K. Walling, D.E. and P.W. Morehead. 1989. The particle size characteristics of fluvial suspended sediments: an overview. Hydrobiologie 176/177:125-149. Walling, D.E., M.R. Peart, F. Oldfield, and R. Thompson. 1979. Suspended sediment sources identified by magnetic measurements. Nat. 281:110-113. Walling, D.E d T.Aan .. Quine. 1990a. Calibratio f caesium-13o n 7 measurement provido st e quantitative erosion rate data. Land Degradation and Rehabilitation 2:161-175. Walling, D.E d .T.Aan . Quine. f caesium-13o 1990b e Us . o t 7 investigate pattern d rate an sf soi o s l erosio n arablo n e fields . 33-53Broadman. J pp , : .In , I.D.I. Foster J.Ad ,an . Dearing (eds.), Soil erosion on agricultural land, Wiley, London.

Walling, D.E T.Ad .an . Quine 'f 37o C. s e 1991ameasurementus e .Th o st investigate soil erosion on arable fields in the U.K.: potential applications and limitations. J. Soil Sei. 42:147- 165. Walling, DTE d T.A.an . Quine. 1991b. Fluvial redistributiof o n Chernobyl radionuclides. NERC News, July 1991 . 22-25pp , . Walling, D.E d .T.Aan . Quine f caesium-13o .e us 1992 e Th 7. measurement in soil erosion surveys. IAES Publ. No. 210:143- 152. Walling, D.E. and T.A. Quine. 1993. Use of caesiua-137 as a tracer erosiof o sedimentationd nan : Handboo applicatioe th r kfo f no e caesium-13th 7 technique K OverseaU. . s Development Administration Research Scheme R4579, Departmen Geographyf to , Unin. Exeter, Exeter, United Kingdom. Walling, D.E., . T.A1992He .. Q . Quine Investigatind an , g contemporary rate floodplaif so n sedimentation, pp.' 165-184. In: P.A. Carling and G.E. Petts (eds.), Lowland floodplain rivers: Geomorphological perspectives. Wiley, Chichester. Walling, D.E., T.A. Quine J.Sd ,an . Rowan. 1992. Fluvial transport d redistributioan f o Chernobyn l fallout radionuclides. Hydrobiologia 235:231-246. Walling, D.E., J.S. Roman, and S.B. Bradley. 1989. Sediment associated transport and redistribution of Chernobyl fallout radionuclides. IAHS Publ. No. 184:37-45.

198 Walling, D.E. and B.W. Webb. 1987. Material transport by the world's rivers: evolving perspectives. IAHS Publ 164:313-329. .Mo . Walling d ,J.C an . D.E. Woodward f o radiometri e . Us 1992. c fingerprint o derivt s e informatio n suspendeo n d sediment sources. IAHS Publ. No. 210:153-164. Walling, D.E., J.C. Woodward d A.P.an , Nicholas. A multi1993. - parameter approach to fingerprinting suspended sediment sources. IAHS Publ 215:329-340. .No . Walton e distributio Th . 1963A ,. n soili n f radioactivito s y from weapon tests. J. Geophys. Res. 68:1485-1496. d P.Han „ . G SantschiWan, . 1987. Predictio f radionuclido n e inventory for sediments in Lake Greifensee, Switzerland. Scientia Geographia Sinica 7:358-363. Wan, G., P.H. Santschi, K. Farrenkothen, M. Strum, and W. Strum. 1985. Distribution and dating of I37Cs for recent sediments in Lake Greifensee (Switzerland). Acta Scient. Circumstantia 5:360-365. Wan, G. , P.H. Santschi, M. Strum, K. Farrenkothen, A. Lueck, E. Werth, and C. Schüler. 1986. A comparative study on recent sedimentation rate Lakn i s e Greifensee, Switzerland, using varve counting and radionuclide dating. Geochimica 9:259-270.

Wan, G.J., P.H. Santschi Strum. ,M . Farrenkothen,K Lucek. ,A . ,E Werth, and C. Schuler. 1987. Natural (210Pb, 7Be) and fallout (137Cs, ^-^Pu, **Sr) radionuclides as geochemical tracers of sedimentation in Greifensee, Switzerland. Cbem. Geol. 63:181-196. Ward ,. Breeden J T.E., Koraisarcik. ,K . PorterR , . CzuczwaJ , . R , Kaminski B.Dd .,an McVeety. 1987. I37Cs radioactive datinf o g Lake Ontario sediment cores. BNL-40550, 10 pp. Brookhaven National Laboratory, Upton, New York Wasson, R.J., R.L. Clark, P.M. Nanninga Waters. J d ,an . 1987. 210Pb chronometea s a traced ran r Burrinjuck Reservoir, Australia. Earth Surf. Processes Landfonns 12:399-414. Wasson, R.J., R.L. Clark, I.R. Willett Waters, ,J , B.L. Campbell, an Outhet. dD . 1984. Erosion histor Burrinjucn yi k Reservoir, . 221-229pp NSW ,R.J : . In . Loughran (ed.), Drainage basin erosio d sedimentationan n , Univ. Newcastle, Newcastle, Australia. Wenning, R.J., N.L. Bonnevie S.Ld ., an _Huntley. 1994. Accumulation of metals, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons in sediments from the lower Passaic River, New Jersey. Arch. Environ. Contain. Toxicol. 27:64-81. Wheeler, D.A. 1988. Atmospheric dispersa d depositioan l f o n radioactive material from Chernobyl. Atmos. Environ. 22:853- 863. Whicker, F.W. 1983. Radionuclide transport processe terrestrian si l ecosystems Radiât. .J . Res. 94:135-150. Whicker, F.W., W.C. Nelson A.Fd .,an Gallegos. 1972. Fallout t37Cs and *°Stroun i r t from mountain lake Coloradon si . Health Phys. 23:519-527. Whicker, F.W., J.E. Pinder III, J.W. Bowling, J.A. Alberts, and I.L. Brisbi 1990. nJr . Distributio long-livef no d radionucliden si an abandoned reactor cooling reservoir. Ecol. Monographs 60:471-496.

199 Whicker, F.W. and V. Schultz. 1982. Radioecology: nuclear energy and the environment. CRC Press, Boca Raton, FL.

Whicker, J.J., F.W. Whicker. JacobiS d an ,. 1994. Cs-13n i 7 sediments of Utah lakes and reservoirs - Effects of elevation, sedimentation rate and fallout history. J. Environ. Radioact. 23:265-283.

Wieland P.H, ,E. . Santschi Beer. J d .,an 1991 .multitrace.A r study of radionuclide n Laki s e Zurich, Switzerland. . Residenc'2 e times, removal processe sedimend san t focussing Geophys. .J . Res. 96:17067-17080. Wilken, R.D., I. Moreira, and A. Rebello. 1986. 2IOPb and 137Cs fluxes ia sedimenn t core from Guanabara Bay, Brazil. Sei. Total Environ. 58:195-198.

Wilkerson, D.F., S. Arya, and B.L. Wilson. 1993. Investigations of radionuclides in the aqueous sediment environment surrounding a coal burning power plant. J. Environ. Sei. Health A28:1005- 1015. Wilkin, D.C. and S.J. Hebel. 1982. ETosion, redeposition and delivery of sediment to midwestern streams. Water Resour. Res. 18:1278-1282. Wilson, G.G., A.E. Litherland J.Cd ,an . Rucklidge. 1984. Datinf o g sediments using accelerator mass spectrometry. Chem. Geol. 44:1-17. Wilson, T.R.S. 1974. Caesium-137 as a water movement tracer in the St. George's Channel. Nat. 248:125-127. Wischmeier, W.H. 1976. Use and misuse of the universal soil loss equation Soi. .J l Water Conserv. 31:5-9. Wischmeier, W.H. and D.D. Smith. 19,65. Predicting rainfall-erosion losses for cropland east of the Rocky Mountains. Agr. Handbook No. 262. USDA, Washington, DC. Wise, S. 1977. The use of fallout radionuclides Pb-210 and Cs-137 in estimating denudation rates and in soil erosion measurements. Geography Department, King's College, London, Occasional Paper . pp 78 ,3 Wise, S.W. 1980. Caesium-137 and lead-210: a review of the technique and application to geomorphology, pp. 109-127. In: R.A. Cullingford, D.A. Davidson Lewi. J d n, an (eds.), Timescalen si geomorphology, Wiley, London. BarzanskyWitkamp. B d an . ,M . 1968. Microbial immobilisatio l37f no C s in forest litter. Oikos 19:392-395. Witkamp M.Ld an .. ,M Frank . 1970. Effect temperaturef so , rainfall and fauna on transfer of l37Cs, K, Mg and mass in consumer- decomposer microcosms. Ecol. 51:466-474. Witinok, P.M. 1992. On the relationship between sediment deposition and lanchangee dus lacustrin a n si e wetland. Doctor's Thesis, Univ. Iowa, Iowa City, Iowa. Wong, G.T.F d C.San .. Moy. 1984. Cesium-137, metal d organian s c carbon in sediments of the James River estuary, Virginia. Estuar. Coast. Shelf Sei. 18:37-49. Wong, H.K.T., J.O. Nriagu, and R.D. Coker. 1984. Atmospheric input of heavy metals chronicled in lake sediment of the Algonquin Provincial Park, Ontario, Canada. Chem. Geol. 44:187-210. Wooldridge, D.D. 1965. Tracing soil particle movement with Fe-59. Soil Sei. Soc Proc. .Am . 29:469-472.

200 Worsley, A.T. and F. Oldfield. 1988. Palaeoecological studies of three lakes in the highlands of Papua New Guinea. II. Vegetational history over the last 1600 years. J. Ecol. 76:1-18.

Wrenn, M.E., J.W. Lentsch, M. Eisenbud, G.J. Lauer, and G.P. Howells. 1971. Radiocesium distribution in water, sediment, and Hudsoe biotth n nai River estuary from 1964 through 1970. Proceedings third national symposiu n radioecologyo m S U . Atomic Energy Commission Ridgek ,Oa . ,TN Yamagata Matsuda. S Kodaira. , K ,N. d ,an . 1963. Run-of caesiumf fo - 137 and strontium-90 from rivers. Nat. 200:668-669. . ZhangY Yan , Liu. ,M. Y . ZhaoQ , . Zhang. ,Li X . . WangS ,Y d ,an cesium-13f 1991o e .Us estimato 7t e erosio' : nIn rates. 16 . ,p Second international conferenc methodn eo applicationd san f so radioanalytical chemistry, Washington, DC. Yushkov, P.I., T.A. Chueva, E.N. Karavaeva, I.V. Molchanovad an , N.V. Kulikov. 1993. Contents of Cs-134+137 and Sr-90 in the crown of birch trees in the first years after the accident at the Chernobyl Nuclear Power Plant. Russia Ecol. nJ . 24:70-74. Zhang, X.B., D.L. Higgitt D.Ed an , . Walling. 1990 .preliminarA y assessment of the potential for using caesium-137 to estimate rate soif so l erosio Loese th sn n i Platea Chinaf uo . Hydrol. Sei 35:243-251. .J . Zhang, X.B., S. Li, C. Wang, W. Tan, Q. Zhao, Y. Zhang, M. Yan, Y. Jiang. LiuJ ,Zhou . XiaoJ . , J d . ,an caesium-13f 1989 o e .Us 7 measurement investigato st e erosio sedimend nan t sourcea n si small drainage Loes e basith sn i nPlatea f Chinao u . Hydrol. Processes 3:317-323. Zhang, X.B., S.L. Li, C.H. Wang, W.P. Tan, Q.C. Zhao, Y.Y. Zhang, M.Q. Yan, Y.L. Liu, J.J. Jiang, J.L. Xiao, and J. Zhou. 1990. A study of sediment delivery from a small catchment in the Loess Plateau by the 137Cs method. Chinese Sei. Bull. 35:38-41. (Chinese) Zhang, X.B. T.A. Quine, D.E .1994. Li Wallin . .Z d Applicatiogan f no the caesium-137 technique in a study of soil erosion on gully slope yaua n Loesnse i areth sf ao Platea u near Xifeng, Gansu Province, China. Geografiska Annaler Serie Physica. sA l Geogr. 76A:103-120. Zucker, C.R., Olsen, I.L. Larsen d N.Han , . Cutshall. 1984. Inventories and sorption-desorption trends in radiocesium and radiocobal Jamen ti s River estuary sediments. Environ. Geol. Water Sei. 6:171-182. Zuo, Z.Z., D. Eisma, and G.W. Berger. 1991. Determination of sediment accumulation and mixing rates in the Gulf of Lyons, Mediterranean Sea. Oceanol. Acta 14:253-263.

201 LIST OF PARTICIPANTS

Bandeira, J.V. Centra de Desenvolvimento da Tecnologia Nuclear Comissäo Naciona Energie ld a Nuclear Cidade Universitâria-Pampulha C.P. 941 30161 Belo Horizonte-MG, Brazil

Dörr. H , Trischle Partned run r GmbH Berliner Allee, 6 Postfach 10 43 22 6100 Darmstadt, Germany

Dubinchuk, V. Ail-Union Research Inst. of Hydrogeology and Engineering Geology (VSEGINGEO) 142452 Zeleny Village, Noginsk District Moscow, Oblask, The Russian Federation

Edgington, D.N. Cente Grear rfo t Lakes Studies University of Wisconsin-Milwaukee 600 East Greenfield Ave. Milwaukee, Wl 53204 United States of America

Elliot.t G. Australian Nuclear Scienc Technologd ean y Organization Lucas Heights Research Laboratories New Illawarra Road, Private1 Maig Ba l Mena 2234W NS i, Australia

Lal, D. Univ. of California, San Diego Scripps Institute of Oceanography 9500 Gilman Drive La Jolla, CA 92093, United States of America

Nijampurkar, V.N. Physical Research Laboratory Navrangpura Ahmedabad 380 009, India

Oldfield, F. Departmen Geographf o t y Universit f Liverpooyo l Roxby Bldg., P.O. Box 147 Liverpoo 3BX9 , L6 l United Kingdom

Ritchie. C . J , USDA ARS Hydrology Laboratory BARC-W Bldg-007 Beltsville, MD 20705, United States of America

Sanders. D , FAO, Soil Resources, Management and Conservation Service Land and Water Development Division Viale délie Terme di Caracalla Rome, Italy

203 Smith. N . J , Marine Chemistry Division Dept f Fisherieo . Oceand san s Bedford Inst Oceanograpgf o . y Dartmouth, Nova Scoti 4A2Y aB2 , Canada

Tartaglia. V . ,C Direcciôn Naciona Tecnologie d l a Nuclear Mercedes 1014, Casill Corree ad o 10.844 11.100 Montevideo, Uruguay

Tazioli, G.S. Université degi Studi di Ancona Dipartiment i Sciencod i Matériaede déliue a Terra Via Brecce Blanche, 60131,Ancona, Italy

Walling, D. E. Universit f Exeteyo r Departmen f Geographo t y Exeter EX4 4RJ, United Kingdom

IAEA PARTICIPANTS/OBSERVERS

Araguâs, L. Isotope Hydrology Section Fröhlich, K. Divisio f Physicano Chemicad an l l Sciences, GonfiantiniR , International Atomic Energy Agency Plata, A. (Scientific Wagramerstrass0 10 , P.O e5 x .Bo Secretary) A-1400 Vienna, Austria Quist, M. Stichler, W. Yurtsever, Y.

Zapata, F. Soil Science Unit, Joint FAO/IAEA Division Wagramerstrasse5 P.O. Box 100 A-1400 Vienna, Austria

OTHER OBSERVERS

Florkowsky. ,T Institute of Physics and Nuclear Techniques University of Mining and Metallurgy AI. Mickiewisza 30 30-050 Krakow, Poland Hien, P.D. Center for Nuclear Techniques 217 Nquyen Trai, Q1 Ho Chi Minh City, Vietnam

Souag, M. Centre de Development des Techniques Nucléaires 2, Boulevard Frantz Fanon Alger, Algérie

0> Elmosly. ,W University of Agriculture ^» O) Institute of Soil Science M O Vienna, Austria in en

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