Re-Suspension of Bed Sediment in a Small Stream

Home , First flush

Open Access erent sed- ff Discussions and the flow vol- 1 Sciences − 3 Earth System Earth , Hydrology and and Hydrology 1 , and G. Blöschl 2 12078 12077 erences between flow velocity and wave celerity along the 590 m reach of the stream. However, a ff 3 , P. Strauss 1 , M. Exner-Kittridge 2 , 1 This discussion paper is/has beenSciences under (HESS). review Please for refer the to journal the Hydrology corresponding and final Earth paper System in HESS if available. Centre for Water Resource Systems, Vienna University of Technology, KarlsplatzFederal 13, Agency for Water Management, Institute for Land and WaterInstitute Management of Research, Hydraulic Engineering and Water Resources Management, Vienna University of occurrence of contaminants and particlestream can bound be elements related such to as the phosphorous abundance in of the fine sediments (Mudroch and Azcue, 1995; by the resuspension oftotal streambed sediment sediments, load accounting depending on for total up flow to volume. six percent of the 1 Introduction Understanding the sediment exportland from and agricultural catchments water is resourcesof important management. phosphorus for Erosion, both are land closely degradation related and to the the transport sediment export (Kovacs et al., 2012). The ond flood due tosection depletion of the of stream streamevent where bed which more can sediments. sediment be The wasand explained transported exception the by during was di resulting the the displacement secondthat middle flood the of first sediments peak within of the the sedigraphs stream. of The natural results events in indicate this stream is indeed caused events may be available forsediments resuspension. at To understand the resuspension reach of scalezenkirchen stream we catchment bed artificially in Austria flooded by theshort pumping small floods sediment-free stream were water produced of into and thesured the flow, HOAL sediment stream. at Pet- and Two three bromide sites concentrations were withwere mea- almost high identical. temporal The resolution. peak Hydrologically,umes flows the decreased decreased two from from flood 17 57 events toconsiderably to smaller 11.3 7.9 m L sediment s load was resuspended and transported during the sec- Streams draining small watershedsated often with exhibit single multiple peaking peakingpeaks hydrographs. are sedigraphs The not associ- fully process understood reasons butiment they of sources may the such be related as multiple to the sediment the streambed activation itself of di where deposited sediments from previous Abstract Re-suspension of bed sediment instream a – small results from twoexperiments flushing A. Eder Hydrol. Earth Syst. Sci. Discuss.,www.hydrol-earth-syst-sci-discuss.net/10/12077/2013/ 10, 12077–12104, 2013 doi:10.5194/hessd-10-12077-2013 © Author(s) 2013. CC Attribution 3.0 License. 1 1040 Vienna, Austria 2 Pollnbergstraße 1, 3252 Petzenkirchen,3 Austria Technology, Karlsplatz 13/222, 1040 Vienna, Austria Received: 26 August 2013 – Accepted: 10Correspondence September to: 2013 A. – Eder Published: ([email protected]) 7 October 2013 Published by Copernicus Publications on behalf of the European Geosciences Union. 5 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | erent sediment ff erences between ff erent, which makes it ff mechanisms (infiltration ff erences in the rainfall intensities ff erent runo ff 12080 12079 cult to measure erosion within a catchment in ffi culty in analysing these processes is related to the hy- ffi cult to unravel the individual factors driving the processes of sedimentation and ffi This paper therefore reports on reach-scale experiments of controlled water inputs Many authors relate these observations to the activation of di There are many processes influencing the erosion, transport, deposition and remo- and the Technical Universityhigh of temporal Vienna and spatial to resolution. study Climate catchment in the processes catchment from can be data characterised with as in the sedigraphsstream of bed? natural events due to the re-suspension of2 sediment from Study the site The flooding experiments(HOAL) were Petzenkirchen conducted (Fig. 2). in Ithas the is a size Hydrological situated of in Open 64 the ha. Air It Western is part Laboratory jointly of operated Lower by Austria the Federal and Agency for Water Management into a smallcesses stream of to fine understand sediments.for Specifically, the an the experimental following resuspension, catchment: science (i) transportiments questions What from and is are the the addressed deposition stream magnitude bed? of(catchment pro- re-suspension (ii) erosion of What during fine is previous sed- events the or source the of channel these bank)? re-suspended (iii) sediments Is the early peak sediments from the fields inon agricultural the catchments. Also, resuspension little ofposited information is fine during available the sediments tailing fromcatchment. limb the of Much bed the of previous ofdrological the events small variability and di between streams the events. transportation that Eachvery out and were di every of de- event the is di resuspension. What is needed are repeatable experiments (Blöschl and Zehe, 2005). sources suchKronvang as et al., the 1997; LenziAlthough and resuspension the Marchi, movement 2000; of from Regües bedload for etthe streambed al., streambed stability behaviour 2000; analyses of Eder is sediments fine well et investigated, sediments, al.,(Petticrew often 2010). (Williams, et simplified as al., 1989; washload, 2007). is less However, well it investigated is the latter that reflects the amount of eroded the timing and shape ofral shift, the resulting hydrographs in and either the clockwiseagainst sedigraphs. or sediment Often, counter-clockwise hysteresis there concentrations, when is and plottingated a flow with multiple tempo- single peaking peaking sedigraphs hydrographs2000; (Kronvag are Petticrew et often et al., al., 1997; associ- hydrograph Brasington 2007; and and Yeshaneh Richards, et the al., associatedwhere 2013). sedigraph small As of sediment an the peakscharge example, peak HOAL often Fig. (Fig. catchment 1 occur 1). shows in in Seegersmall a headwater et Petzenkirchen advance catchment al. of in (2004) the the observed Spanish main similar Pyrenees. early sediment sediment and peaks dis- in a and spatial rainfall patterns2012). (Soler In et large al., catchmentssedigraph 2008; because not Lana-Renault, of all 2009; long ofthere Giménez pathways tends these et and to process be the al., a variations averagingever, close in of may correspondence small component between be catchments sedigraphs processes, many and visible scientists so hydrographs. in have How- observed the massive di much of the sedimentstream is network deposited itself prior priorRose et to to al., reaching reaching 2003). the the stream catchment or outlet deposited (Merritbilisation in of et sediments. the al., Most of 2003;the hydrograph these shape De factors is similar. vary There significantly isand seasonal between antecedent variation events due soil even to moisture, vegetation if dynamics variationexcess vs. due saturation to excess) di and variation due to di a representative way due1988; to Prosser the et enormous al.,common spatial 2001a), way of monitoring variability indirectly the in measuring sedimentmany catchments the environments concentrations bulk (Walling, sediment erosion in losses from measured streams the onthe is the catchment. sediment field However, a in scale loads are much measured higher in than the stream (e.g. Millington, 1981). This is because Quinton et al., 2003). While it is di 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | . The 1 − during a big flood in 2002. 1 − s 3 C and a mean annual rainfall of 716 mm. ◦ 12082 12081 but flow drops down in summertime to less than one litre 1 − but it was not possible to empty the water reservoirs completely, so the actual 3 At the catchment outlet (site MW) we measured flow with an H-flume and a pressure The weather and the hydraulic conditions in the stream prior to the flooding events Flow in the stream at site 590 was measured by a calibrated H-Flume fitted with Low gradient sections of the stream with small water velocities tend to be covered In the upstream section of the stream, bank slope ratio is almost 1 : 1. The stream is base flow conditions were reached again. It is assumed that only a negligible part and automated sampler data for each single site separately. transducer, at one minute intervals.atures Turbidity, electrical were measured conductivity also and at water oneusing temper- minute the intervals. same Additionally procedures we took as water for samples sites 360 and 160. were almost identicalto (Fig. rise 5). a Although few there days was in some advance rain of both and flooding discharge experiments, began directly before the tests first increase of theutes attainable water with level the becauseof sampler the interest. was minimum The considered sampling to waterand samples be interval bromide too were of concentration long analysed five in for forculated min- the the suspended from laboratory. flow sediment Final the dynamics concentration sediment readings concentrations of were the cal- turbidity probes which were calibrated with manual water volume pumped into the stream was somewhat lower. a pressure transducerthe where flow water measurements levels at werestreambed. site logged At 360 both at and sites oneature site we at minute 160, recorded one intervals. V-notch water minute For weirsfor level, intervals were the turbidity, and conductivity installed took first and in manual 40samplers min temper- the water were after samples installed at the two atthe first minute tail these increase intervals of sites of the with the flood a water waves. sampling level. We Additionally, did interval automated not of use 20 min the to automated samplers capture directly after the reservoirs were fitted withpumps pumps with were a started nominaldirectly with flow at rate a site of 590. delay a The flow ofthe total from of stir one the hoses 56.7 up minute L was s of stabilised and24 in sediments m a pumped from wooden the water box to streambed. into minimise The the total stream capacity of the reservoirs was of the open streambefore (site the 590 flooding in experiments. Fig. Bromide 1). was They added were to filled the with water stream as water a one tracer. day The by deposited fine sedimentsvisible. whereas At in the the later the steep quaternaryand sections underground resistent the is against often quartanary erosion. coated material with precipitated is carbon 3 Experimental setup Two flooding experiments were conductedPrior in to 2011 the experiments, on three 24 temporary and water reservoirs 31 were August, set respectively. up at the beginning The banks aresmall very river shallow bed is and flooded areincrease it in takes flooded water a level. during substantial The increaseof medium longitudinal in steps, section sized flow followed of to by floods. the produce pools stream After a and (Fig. significant sections the 3) with shows varying a slopes. number per second. Maximum observedThe flow stream was around itself 2 has m Additionally, an the open length upper of mostenlarge 590 the m 25 agricultural % with production area. a of Thein medium piped the the section slope of length stream of the of 2.4 stream length 590 % is m. not were (Fig. included 3). piped invery the narrow and 1950s a change to area in flow of leads the to catchment a significant outlet change the in stream the reaches water level. a In width the of approximately one meter. Temperature, rainfall and rainfallelevation intensity of the have catchment theirsoil ranges peak types from are during 257 Cambisols to summertime.capacities and 325 and m The Planosols underlying above geology (FAO, sea 1998) oflast level. quarternary with decade The medium sediments. was dominant Mean to 3.8 annual L poor s flow infiltration of the humid with a mean annual temperature of 9.3 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 1 − at sites 1 − at sites 360, 160 and 3 . The close similarity of 3 volume is almost identical. In ff erences in sediment characteristics for flood at site 590 to 21.5, 10.0 and 8.7 L s 12084 12083 at the downstream sites. The measured water ff 1 1 − et al., 2007). − ff to 14.7, 12.9 and 11.7 m 3 and decreased to 15.2, 13.3 and 11.3 m 3 which is close to the nominal capacity of the pumps. There is a 1 − To shed light on the sources of the transported sediments Fig. 9 compares the time The hydrographs of the second experiment (Fig. 6b) are almost identical to the hy- thus direct erosion of the streamis bed a can local be phenomenon excluded. Bank and erosion, can on never the be other excluded. hand, However, the immediate increase in in Fig. 5, thereexperiments, was so no we impact can ofmoisture safely rainfall and assume on groundwater that tables) the were the base veryof hydrological similar. flow This sediment conditions conditions similarity processes (including allows purely between a based soil the comparison onthe two the experimental availability setup of sediments it in wasTherefore, the ensured the stream. that With only no sediment sediment sourcesposited was were sediments delivered of the previous from stream events. the Due bedmolassic fields. to itself, subsurface the and stream fact has banks that been or the stable stream de- for bed several decades, is a cut further into deepening the and events identical replicas fromperiments approximately the equal perspective flowalong maxima of were the water measured stream. flow. at Also, Inboth the the experiments, individual the decrease apparently, exfiltration stations of two into the thecurred flooding groundwater total as and ex- runo surface would ponding be oc- expected for this type of events (Wondzell et al., 2010). As shown that first detection of bromide occurred later than the rise of the5 hydrograph. Discussion 5.1 (a) Source and magnitude ofThe re-suspended most sediments striking featureidentical. of Indeed the the two experiments experiments were is designed that in the a hydrographs way are to almost make the two flooding the sediment concentrations atand the 55 individual min sites after starting along the17, the pumps 34 stream (Fig. increased and 9b). 18, In 53of min the 33 second after bromide experiment starting occurred they increased the 20,experiment after pumps. 38 20, In and 41 the and 86 75 min first min at after experiment sites the starting 360, 160 first the and detection MW, pumps, respectively. This and means in the second sediments is simultaneous with the first rise of the hydrograph. In the first experiment (Fig. 9a). Since the hydrographslags of for the the second two event experiments are are very almost similar identical, (17, the 32 time and 52 min). The first appearance of the hydrograph characteristics is importantas as the repeated flooding experiments experiments to werewaves designed infer that are the otherwise di similar. lags of the hydrographof dynamics representing the wave sediment celerities (Fig.velocities (Fig. (Fig. 9b) 9a), 9c). the and The time thestarting lags first the time rise pumps. lags It of took of the 32 min the hydrograph to at bromide see site the tracer first 360 representing rise occurred at flow 18 site min 160 after and 54 min at the MW through the hyporheic zone (Goose drographs of the firstat experiment. the pumps The to maximum 20.7,volumes flow 9.9 decreased rates and from 7.9 decreases L 17.1 s m from 57 L s The hydrographs of theexperiment two (Fig. flooding 6a) experiments590) the are maximum was 57 flow shown L s rate instrong dispersion measured Fig. of at 6. the theflow For flood rate pumping the along wave station first the and stream thus360, (site from 160 a and 57 L significant the s catchment reduction outlet,the of respectively. stream The was the total 16.9 volume m maximum ofthe water catchment pumped into outlet, respectively. Thei.e. reduction in storage volume in is due either to stream transient storage, channel dead zones (side pools, eddies) or exchanges because turbidity did not show a clear response to the increased flow4 rate. Results of sediment was transported at the natural rainfall event between the flooding tests, 5 5 20 25 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | erences ff events in the catchment erences in sediment avail- ff ff ered although the hydraulic condi- ff 12086 12085 It is now of interest to compare the flooding experiments with natural events. Data of However, contrary to our initial expectations, at the middle section (site 160) the sed- The sediment load transported by the stream at the various sections decreased both the flooding experiments and thethe natural relationships events for are the plotted flooding in experiments Fig. (Fig. 10. 10a) On and average, the natural events from the rainfall intensities thecatchment time outlet for is transporting notour long eroded experiments, enough the sediments to main from take partaround these of the the 80 sediments fields event out mins was of to around toremain the 20 the somewhere reach mins catchment. on while the In the it catchment pathway. took outlet. the water Most ofnatural the events sediment from the must years therefore for 2006 the and comparison. 2007 Relationships taken between from sediment Eder concentrations et and discharge al. for (2010) were used A crucial point of thethe study first was flush the sediment comparisonthat load of the of the first resuspension natural experiments flush events.are with The sediment indeed results peak caused of of the by a experiment resuspension. natural suggest Especially rainfall-runo for short duration storms with high rate with the mainsoning stream and suggests therefore that depends the onrelative higher to the sediment the discharge. loads first This at are processability site along real rea- the 160 and stream. in can However, the thebed be main were second explained pattern depleted experiment by is during the that the the di catchment first sediments outlet experiment, on leading in the to the stream smaller second sediment experiment. loads at the 5.2 (b) Comparison with natural events Because of the higherdownstream ratio part between less sediment celerity was andfrom transported the velocity in upper and this part section. lower ofometry The flow the with sediment reach rates small delivery is at steps limited. followed the Furthermore,One by pools the would which stream expect may has act that a as complex the temporary ge- influence sediment sinks. of these pools is related to the mean exchange until site 160. These sediments were then easily available for the second flooding. erable amount of fine sediments was transported during the first flooding experiment (Table 1), indicating thatstream section. transport Due velocity to the isto immediate increase, rise lower the of than sediments sediment concentrations must wavemeasurement when originate site. celerity flow from Because starts the in of streambed the thebetween short directly celerities down- upstream duration and of of velocities, the the the floodlength sediments wave are and and likely re-deposited the transported as di for theafter only its a transport limited maximum. capacities This decrease interpretationdistance when of the studies limited wave transport within recedes lengthBrun flumes is (1999). from supported These by results, Parsons travel along and with the Stromberg data (1998) from this and study, Bryan suggest that and a consid- iment load of the secondPossible experiment reasons increased by for 10 this %change relative increase to in are the the first a experiment. bank availabilitythe bromide collapse of tracer upstream sediments results. of The alongproximately ratio the the unity between site at wave stream. celerity and/or the The and a upper bromide latter section velocity is and is ap- increases supported to by 2.2 near the catchment outlet along the stream. Thisties according is to transport consistent capacity withthe concepts sedigraphs (e.g. the Merrit of decreasing et the al., dischargetions two 2003). were and As flooding identical. noted experiments flow At above, site di veloci- smaller 360 than the that sediment of loadthe of the second the first experiment second experiment. was experiment At even was 72 the 22 % % catchment smaller outlet than the that of sediment the load first of experiment. of the sediments isstream resuspension bed of or previously fromicant deposited the less sediments, flood sediment either plains. was This fromhydraulic transported is the conditions during also were the supported identical. secondhave by been flooding Thus, the depleted experiment the during finding although the sediment that first signif- deposits experiment. on the stream bed sediment concentration at the onset of the hydrograph suggests that the main source 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ) but lowest 3 ects to more fully understand ff 12088 12087 ) but highest relative first flush sediment load. 3 erent sections of the stream (12.6 kg to 0.6 kg along ff erences in the sedigraphs in this study. If a summer storm with high erosion ff ected by the deposition characteristics of the previous event, as demonstrated ff Our future work will focus on the depletion of streambed sediments during long last- As the event magnitude of the natural events increases, the relative contribution of The contribution of the first flush sediment load is much smaller than the figures for For evaluating the resuspension during natural events, six events were selected ing events, including grain size analyses and hysteresis e pended sediment load decreased fromthe 16.2 kg decrease to of 2.2 flow. kgand During along the transported the stream second through according experiment the to the less stream) di sediment due to was the resuspended evaluation depletion of of easily flow available sediments and fromnatural the events travel streambed. in times The this indicates streamiments. is that The indeed sediment the caused loads by first of0.1 the the peak and resuspension first 6 of of % peak streambed of the of sed- the natural sedigraphs total events of sediment may load, contribute depending between on total flow volume. 6 Conclusions Two flooding experiments in a streamdicate draining resuspension a of small agricultural fine catchment sediments clearly from in- the streambed. At the first experiment sus- much sediment will below available intensities for and the low erosion followingand rates event. may not In resuspend leave contrast, most much a of sedimenttribution the long for streambed of event sediments the with the following event.instance available Furthermore, Petticrew and (2007) the reported transported grain thatported size sediments more dis- during will mass but the play smaller falling aneasily grain limb available sizes important of sediments were when the trans- role. the hydrograph. For ratio This between could flow lead celerity and to velocity a is big high. resource for catchment or just displacedparticular within on the the reach duration depends andalso on magnitude a the of the event characteristics, event.by The in the amount di of resuspensionrates is but short duration transports a lot of sediments from the fields to the stream, high enough, resuspension will happen. Whether the sediment is exported from the are available in the stream bed and the critical shear stress or transport capacity is as a result ofevents. The the March depletion 2007 ofcontribution event of the exhibits first a sediment large flush depositsshows total lowest peak on total flow to flow the volume volume total stream (584 (88 sediment m m bed load. during Contrary, the bed/bank the erosion April reported in 2006 the literature.a event For contribution example, Kronvag of et 66–89 al. % (1997)that for reported in the the low land casepension river of but in the Denmark. resuspension HOAL Therefore, also catchment it occurs the is very later first likely sediment during peak the is event. caused As by long resus- as sediments June 2007 event can be thethe planting catchment of and maize the on less thethe developed most plant soil sensitive stadium was fields at not for that covered erosion time and in of easily the erodible. year. Therefore, the first flush relative to the total load decreases (Fig. 11). This would be expected contribution of the firstsults indicate flush that sediments the to proportionload of the is first between total flush 0.1 sediment (resuspension) andexperiments 6 sediment load %. are load For (Table reported. to comparison, 2). the The the The total corresponding sedimentare values re- listed concentrations of under and the first loads flooding peak ofexperiments as the was they experiments 2.2 stem from andral resuspension. 1.6 events The kg usually total respectively, ranged export while betweenevent. of the 0.1 the A and first two 5.6 possible flush kg reason with export the for of exception the the of the natu- extraordinary June high 2007 sediment concentrations of the is available for resuspensiontwo in experiments the are much natural morebecause events. consistent of However, than the the those similarity relationships of in of the the hydrological individual the conditions. natural events where a clear first flush peak could be identified. These were used to calculate the years 2006 and 2007 (Fig. 10b) are very similar. This suggests that enough sediment 5 5 20 25 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | erent hydro- ff ects (in the Petzenkichen catchment, Austria), ff 12090 12089 , 2007. We would like acknowledge financial support from the Austrian Science , M. N., Hall Jr., R. O., and Tank, J. L.: Relating transient storage to channel complexity ff 10.1029/2005WR004626 tions and discharge(Vallcebre, in Eastern Pyrenees), two Geomorphology, 98, small 143–152, research 2008. basins in a mountainous Mediterranean area from Australia, Mar. Freshwater Res., 52, 81–99, 2001a. for soil phosphorus testsSci., to 166, 432–437, predict 2003. phosphorus losses in overland flow, J. Plant Nutr. Soil age in a gravel-bed river2007. using controlled reservoir releases, Hydrol. Process., 21, 198–210, Large-scale patterns of erosion and sediment transport in river networks, with examples unconstrained particles in interill flow, Water Resour. Res., 34, 2377–2381, 1998. Dolomites (Northeastern Italy), Catena, 39, 267–282, 2000. models, Environ. Modell. Softw., 18, 761–799, 2003. basins in Sierra Leone,Symposium, in: 485–492, 1981. Erosion and Sediment Transport Measurement, Proc. Florence abandoned farmland catchment in34, the 1291–1301, Central 2009. Spanish Pyrenees, Earth Surf. Proc. Land., Factors controlling sediment export inWater a Manage., small 110, agricultural 1–8, watershed in 2012. Navarre (Spain), Agr. phosphorus emission hotspots in2012. agricultural catchments, Sci. Total Environ., 433,transport 74–88, and delivery pathways inProcess., an 11, arable 627–642, catchment, 1997. Gelbaek stream, Denmark, Hydrol. 32/03, 2003. sediment loads with respectJ. to Hydrol., hysteresis 389, e 168–176, 2010. in streams of varying landdoi: use in Jackson Hole, Wyoming, Water Resour. Res., 43, W01417, 2005. ments in the Nepal Middle Hills, Hydrol. Process., 14,application 2559–2574, to 2000. the development of banded vegetation, Catena, 37,and 147–63, Nutrient 1999. Transport in the Murray-Darling Basin, CSIRO Land and Water Technical Report interest to compare the results oflogical this conditions. study with similar experiments for di the physical processes of in-stream sediment transport. Furthermore, it would be of Soler, M., Latron, J., and Gallart, F.: Relationships between suspended sediment concentra- Quinton, J. A., Strauss, P., Miller, N., Azazoglu, E., Yli-Halla, M., and Uusitalo, R.: The potential Prosser, I. P., Rutherford, I. D., Olley, J. M., Young, W. J., Wallbrink, P. J., and Moran, C. J.: Petticrew, E. L., Krein, A., and Walling, D. E.: Evaluating fine sediment mobilization and stor- Parsons, A. J. and Stromberg, G. L.: Experimental analysis of size and distance of travel of Millington, A. C.: Relationship between three scales of erosion measurement on two small Merritt, W. S., Letcher, R. A., and Jakeman, A. J.: A review of erosion and sediment transport Lenzi, M. A. and Marchi, L.: Suspended Sediment Load During Floods in a Small Stream of the Lana-Renault, N. and Regüés, D.: Seasonal patterns of suspended sediment transport in an Giménez, R., Casalí, J., Grande, I., Díez, J., Campo, M. A., Álvarez-Mozos, J., and Goñi, M.: Kronvang, B., Laubel, A., and Grant, R.: Suspended sediment and particulate phosphorus Kovacs, A., Honti, M., Eder, A., Zessner, M., Clement, A., and Blöschl, G.: Identification of Eder, A., Strauss, P., Krueger, T., and Quinton, J. N.: Comparative Calculation of Suspended Goose DeRose, R. C., Prosser, I. P.,Weisse, M., and Hughes, A. O.: Patterns of Erosion and Sediment Brasington, J. and Richards, K.: Turbidity and suspendedBryan, sediment R. B. dynamics and in Brun, small S. catch- E.: Laboratory experiments on sequential scour/deposition and their Blöschl, G. and Zehe, E.: On hydrological predictability, Hydrol. Process., 19, 3923–3929, References University of Technology. We areScheibbs especially for grateful the to theEdith free fire loan Brandstetter, brigades of of Charles-Oliviermarie Petzenkirchen the Corbeil, and Hoesl, pumps Silvia Julia and Jungwirth,ther Derx, Miriam Matthias Schmid, Karner, Ricarda Abietar, Margaret Carmen Franz Frenzl,Markus Stevenson, Krammer, Aigner, Wittek Peter Hose Rita Thomas and Luis Haas, Sturmlechner, Robert Bauer, Salinas, Wittek Johannes Rose- Guen- for Wagenhofer, assisting Stefan with the Wippl, field experiments. W1219-N22). We would alsodrology like Open to Air Laboratory acknowledge (HOAL) funding through of the Innovative part Projects of Programme of the the equipment Vienna in the Hy- Acknowledgements. Funds (FWF) as part of the Vienna Doctoral Programme on Water Resource Systems (DK-plus 5 5 30 25 20 15 10 25 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ) 1 − ) (m s 1 − ) (m s 1 − ) (m s 1 − ) (m s 12092 12091 1 − Event 1 Event 2 ) (m s 1 − ) (m s 3 , M. N., and McGlynn, B. L.: An analysis of alternative conceptual − ff Mean Flow velocity Flow velocity (10 gradient celerity velocity tracer celerity velocity tracer topographic Wave Sediment from bromide Wave Sediment from bromide Wave celerities estimated from the hydrograph dynamics, velocities of sediment trans- Site 590 to 360Site 360 to 160Site 160 to MW 31 17 0.213 22 0.238 0.121 0.213 0.222 0.116 0.192 0.185 0.056 0.225 0.222 0.133 0.225 0.196 0.140 0.192 0.159 0.078 events in rivers, J. Hydrol., 111, 89–106, 1989. models relating hyporheic exchangerecession, Hydrol. flow Process., to 24, diel 686–694, 2010. fluctuations in dischargeport during in the baseflow Koga Catchment,Process., North in Western press, Ethiopia 2013. and environmental implications, Hydrol. 100, 113–141, 1988. Table 1. port estimated from the sedigraphsples. and All flow estimates velocities are estimated for from the the first bromide appearance tracer (first sam- rise) of the signal as in Fig. 9. Wondzell, S. M., Goose Yeshaneh, E., Eder, A., and Blöschl, G.: Temporal variation of Suspended Sediment trans- Williams, G. P.: Sediment concentration versus water discharge during single hydrological Walling, D. E.: Erosion and sediment yield research – some recent perspectives, J. Hydrol., 5 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

15 kg kg % 1 − 2012 ion (590) and measurement sites (360, h and double peaking sedigraph in the mg L 12094 12093 1 − mg L 1 − L s 3 m Water Max. Max. sediment Max. sediment Sediment Sediment Contribution of volume discharge concentration concentration load of event load of first peak of event of event of event of first peak of event first peak to total load Characteristics of natural events and the flooding experiments at the outlet of the Natural event with single peaking hydrograph and double peaking sedigraph in the HOAL 29/04/200629/10/200601/01/200701/03/2007 88.610/06/2007 92.2 360.828/07/2012 583.7Experiment 19.0 1 255.2Experiment 15.5 2 11.5 661.3 21.7 13.3 21.6 15.9 51.7 3156 8.69 570 7.94 712 729 26565 2340 1083 –> 317 166 –> 8243 373 94.6 499 20.3 143.2 2481.3 890 215.1 5.6 290 145.9 42.0 0.5 0.1 1.8 –> 1.1 –> 6.0 1.7 2.3 0.1 2.2 0.8 1.6 0.8 – –

HOAL Petzenkirchen Petzenkirchen on 28 July,HOAL catchment ha) (0.64 Fig. Fig. 1: Natural event with single peaking hydrograp

Fig. Fig. 2: HOAL catchment with point of flood initiat 160, MW) Fig. 1. Petzenkirchen catchment (0.64 ha) on 28 July, 2012. Table 2. HOAL catchment (64 ha). The sedimentunder concentrations ﬁrst and peak loads as of they the stem experiments from are resuspension. listed 3 4 2 1 5 6 7 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

15 2012 ion (590) and measurement sites (360, h and double peaking sedigraph in the 12096 12095 HOAL catchment with point of ﬂood initiation (590) and measurement sites (360, 160, Longitudinal section of the stream in the HOAL catchment with measurement sites.

HOAL Petzenkirchen Petzenkirchen on 28 July,HOAL catchment ha) (0.64 Fig. Fig. 1: Natural event with single peaking hydrograp

17 d during the flooding events in August 12098 12097 Hyetograph and discharge ten days before and during the ﬂooding events in August Upstream section of the stream in the HOAL catchment close to the pumping station

2011. Fig. Fig. 5: Hyetograph and discharge ten days before an Fig. 5. 2011. (left) and downstream section closein to the the photos catchment outlet for comparison. (right). Width Both of photos stream are is upstream indicated views. Fig. 4. 1 3 4 5 2 19 18

ev.2) ev.2) flooding experiments at the three (ev.2) (ev.2) flooding experiment at the flood Fig. 2). Fig. 19 18

monitoring locations (see Fig. 2). locations (seemonitoring Fig.

Fig. Fig. 7: Sedigraghs of the first (ev.1) and second (

initiation location and three monitoring sites monitoring initiation (see three location and

Fig. Fig. 6. Hydrographs of the first (ev.1) and second 12100 12099 4 5 3 1 2 3 4 5 1 2 ev.2) ev.2) flooding experiments at the three (ev.2) (ev.2) flooding experiment at the flood Fig. 2). Fig. Hydrographs of the first (ev.1) and second (ev.2) flooding experiment at the flood initia- Sedigraghs of the first (ev.1) and second (ev.2) flooding experiments at the three monitoring locations (see Fig. 2). Fig. 7. Fig. 6. tion location and three monitoring sites (see Fig. 2). monitoring locations (see Fig. 2). locations (seemonitoring Fig.

Fig. Fig. 7: Sedigraghs of the first (ev.1) and second (

initiation location and three monitoring sites monitoring initiation (see three location and

Fig. Fig. 6. Hydrographs of the first (ev.1) and second 4 5 3 1 2 3 4 5 1 2 21 21 20

21 for the two ads ads transported along the stream for the er flow is from left to is left flow from er right. (c) d from the first appearance (first rise) of (b) (b) and bromide (velocity) (c) for the two

20 and bromide (velocity) d from the first appearance (first rise) of (b) (b) (b) and bromide (velocity) (c) for the two

two flooding experiments two flooding 1 and 2). (event event Wat

Fig. Fig. 8: Comparison of water volumes and sediment lo flooding flooding experiments (event 1 and event 2) estimate Fig. Fig. 9: Time lag of water (celerity) (a), sediment

the signal.the 12102 12101 4 5 3 1 2 , sediment 2 1 3 4 (a) ads ads transported along the stream for the er flow is from left to is left flow from er right. flooding flooding experiments (event 1 and event 2) estimate Fig. Fig. 9: Time lag of water (celerity) (a), sediment

the signal.the 2 1 3 4 Time lag of water (celerity) Comparison of water volumes and sediment loads transported along the stream for the two flooding experiments (event 1 and event 2). Water flow is from left to right. Fig. 8. Fig. 9. flooding experiments (event 1the and signal. event 2) estimated from the first appearance (first rise) of

two flooding experiments two flooding 1 and 2). (event event Wat

Fig. Fig. 8: Comparison of water volumes and sediment lo flooding flooding experiments (event 1 and event 2) estimate Fig. Fig. 9: Time lag of water (celerity) (a), sediment

the signal.the 4 5 3 1 2 2 1 3 4 22

23 ns and discharge of the flooding m Eder et al., 2010) in the HOAL 22 64 ha), see Table 2. see Table 64 ha),

l sediment of load natural asevents a function catchment. experiments (a) and natural events (b, modified fro

Fig. Fig. 10: Relationship between sediment concentratio 12104 12103 4 5 3 1 2 ns and discharge of the flooding m Eder et al., 2010) in the HOAL , modified from Eder et al., 2010) in the HOAL catchment. b and natural events ( Relationship between sediment concentrations and discharge of the flooding experi- Ratio of first flush sediment load to total sediment load of natural events as a function (a)

of total volumeof flow in in the HOAL the catchment ( Fig. 11: RatioFig. of first flush sediment load to tota Fig. 11. of total ﬂow volume in the in the HOAL catchment (64 ha), see Table 2. Fig. 10. ments catchment. experiments (a) and natural events (b, modified fro

Fig. Fig. 10: Relationship between sediment concentratio 3 2 1 4 5 3 1 2