WATER & ENVIRONMENT NEWS

WATER & ENVIRONMENT NEWS A Quarterly Newsletter of the IAEA Subprogramme on Development and Management of Water Resources Photo credit: E. Gibert-Massault

Erg Chech in the Sahara desert (Algeria)

CONTENTS

IAEA Sub-programme on Water Resources 2 Groundwater Renewal in Water (1999 - 2000) Scarce Areas 12 Thematic Planning : Isotope Hydrology Isotopes for Water Resources in in Dam Safety and Sustainability 3 the Asia and Pacific Region 13 Programme Review : Isotope Hydrology for Isotopes For Improved Drinking Water Water Resources in Arid and Semi-arid Regions 5 Resources Management 13 The Xth International Symposium on Isotope Sustainable Development of Techniques in Water Resources Development Groundwater Resources 14 and Management 9 Training Course on Chemical Modelling 15 Technical Review : Groundwater Problems ISOHIS Data Base 15 studies in the Thar desert India, using Isotopes 10 Isotope Hydrology Calendar 16

Issued by the

International Atomic Energy Agency Vienna, Austria

ISSN 1020–7120 Issue No. 7, April 1999 Quarterly No. 7, April 1999 - Page 1 WATER & ENVIRONMENT NEWS

IAEA SUB-PROGRAMME ON DEVELOPMENT AND MANAGEMENT OF WATER RESOURCES (1999-2000)

OBJECTIVES PROJECTS Hydro-climatic Changes and Impact on Catchment Human Impact on Wa- and Surface Water Sys- · to assist in the wider use ter Resources (F4.01) tems (F4.03) of isotope techniques in ap- plied research and practical · to further improve and en- · to assess and verify the ap- field applications related to hance isotope methodolo- plication of isotope method- sustainable development gies applied to a wide spec- ologies in studying processes and optimum management trum of hydrological prob- in the atmosphere and hydro- of water resources; lems encountered as a result sphere related to natural and of water utilization prac- man-induced environmental · to provide support for ef- tices that induce adverse ef- changes, fective integration of iso- fects on available water re- tope methods in national sources, and · to permit improved predic- activities in this field, and to tion of their possible future promote research and field · to attain improved water impact on water resources, studies related to man - management practices that and induced changes and their would minimize water qual- hydroclimatic impact on the ity degradation due to hu- · to enhance the contribution water cycle and its interac- man activities. of isotope applications for im- tion with other environmen- proved assessment of fluvial transport processes and mini- tal systems. Water Resources in Re- mize the adverse effects of gions of Water Scarcity such processes on soil and (F4.02) water resources. · to contribute and improve Contact Us the quantitative assessment Isotope Hydrology Section Analytical Services and and protection of water re- Quality Assurance (F4.04) International Atomic Energy Agency sources in regions of water P.O. Box 100, Wagramer Strasse 5 scarcity, in particular in · to provide assistance and. A-1400, Vienna arid and semi-arid areas, support in the determination AUSTRIA and of the isotope and chemical composition of water and Head of the Section · to assist and. provide sup- other environmental materials Mr. Klaus Froehlich port to Member States for and to assure analytical qual- Tel. +43-1-2600-21735/21736 effective incorporation of ity. Fax: +43-1-26007 isotope methods in routine e-mail : [email protected] practices for estimation and Support to Technical Co- verification of hydrological operation Programmes field parameters for opti- Visit Us on the (F4.05) mum management of scarce Internet water resources. · to provide technical support to the Agency’s technical co- http://www.iaea.org/programmes/ripc/ih/ operation projects in Member index.html The projects are being imple- mented by the Isotope Hydrology States. Section and the Agency’s Laboratories.

Quarterly No. 7, April 1999 - Page 2 WATER & ENVIRONMENT NEWS

EDITORIAL

he current issue of Water & appreciation to his efforts in making Sustainability. Through feedback Environment News is fo- this newsletter a successful source T from governments, the sustainabil- cused on “Isotopes and Water of information four our readers ity and safety of dams and reser- Resources in Arid and Semi-arid world-wide. voirs have been identified, as ar- Areas”, a major component of eas where the application of iso- the Isotope Hydrology Section‘s I am pleased to inform that Dr. tope hydrology can have a signifi- activities for about three Cheikh GAYE, our new staff mem- cant impact on socio-economic de- decades. More than 30 percent ber, has taken over this task. I am velopment, in terms of both cost- of our current TC projects and sure he will do the job with the same savings and safety for residents. part of our applied research pro- dedication and effort. gramme activities are related to As will be announced in the staff this field. change notice, Dr. PANG Zhonghe Klaus Froehlich recently left the Agency and re- Some other activities related to Head, Isotope Hydrology Section turned to his institute in China. He this topic will also be included in was in charge of designing of the this issue. original content and layout of the newsletter and was its editor for the One theme is the newly ap- first 6 issues. On the occasion of proved Thematic Plan - Isotope his departure from the Section, we Hydrology in Dam Safety and would like to express our sincere Thematic Plan - Isotope Hydrology in Dam Safety and Sustainability s part of the efforts to improve dropower generation. Their ability lems from planning through opera- Athe planning of the Agency’s to function properly for a long time tions. However, three techniques future Technical Co-operation pro- is crucial to the well being of these were identified as having a primary grammes, a consultants meeting population segments. Very large role for investigating certain types of on Isotope Hydrology in Dam investments are therefore neces- problems common to dam manage- Safety was organised by the IAEA sary each year to increase the effi- ment: Department of Technical Co- ciency of dam and reservoir opera- operation at the Agency’s Head- tions and thereby improve socio- · water “fingerprinting” through its quarters in Vienna, from 1999. The economic development. Among isotopic composition to identify meeting was attended by interna- other problems, funds are largely the origin and pathway of water in tional experts from Africa, Asia, used for engineering and construc- the hydrological cycle during all Europe, Latin America, the World tion to mitigate three types of prob- phases of a dam project, from Bank, the International Commis- lems: planning through operations sion on Large Dams (ICOLD), the private sector and IAEA. Its main · leakage from reservoirs that · investigation of sedimentation in objective was to help IAEA identify flows under and around dams the reservoir resulting from ero- the end users for isotope technolo- sion in the watershed during the gies so that the technical co- · leakage through dams first filling and subsequent opera- operation can produce socio- tions for purposes of managing economic impact through these · sediments that have deposited the sediment end users. Priority areas of studies in the reservoir and depleted its were identified and pilot countries storage capacity. · investigation of leakage path- for joint IAEA - World Bank assess- ways through and around the ments were proposed by the partici- Isotope hydrology offers tech- dam and through the reservoir pants. niques for assisting with site selec- floor during the first filling and tion, site investigations, watershed subsequent operations, if lea- Development need, technical so- studies, dam and reservoir design, kage is observed. lution and nuclear technology dam construction, dam and reser- voir leakage investigations, sedi- Some isotope methods, while ha- Dams and reservoirs are vital to the ment control and improving reser- ving the potential of providing new sustainability of a large part of the voir longevity. Most techniques and unique technologies for ad- world’s population for water supply, play a catalytic role by supplement- dressing specific dam and reservoir irrigation flood protection and hy- ing conventional technology for solving dam management prob- General News

Quarterly No. 7, April 1999 - Page 3 WATER & ENVIRONMENT NEWS problems, need further research ties are integrated with national larly promising for applications in dam and development. This includes plans and programmes and help safety. One of the potentially most isotope methods for tracing the generate a number of success useful of them is the tracking of sedi- origin of sediment within the wa- stories which could be dissemi- ments that cause reservoirs to become tershed system. These methods nated to a wider audience. The progressively filled with silt. must be validated before they IAEA should initially participate in can become accepted tools for a number of World Bank missions The objective of these pro-active mea- dam management. where the conditions of adequate sures will be to build a demand for counterpart structure and relevant isotope methods in dam management The TC approach for achieving problems are expected to be met. which should, over time, lead to an project impact is to make sure increase in the requests for assistance that its investments in institu- With the help of the World Bank, in this area via the traditional channels. tional capacity-building reach the a list of countries has been se- end-user - the last link in the lected which fulfill the criteria of : Extract from the IAEA approved chain that connects the Agency Government commitment and ex- Note counterpart with the problem isting dam problems. Thematic plan - Isotope Hydrology in holder. Since most of the end- Dam Safety and Sustainability users of analytical technology for (2) Expanded Informational Activi- dam safety and sustainability are ties commercial enterprises, interac- Presentation at Meetings tion with the private sector is An aggressive information cam- by IHS Staff crucial to ensure the successful paign should be launched to sen- application of isotope techniques sitise the end users to the benefits Yuecel Yurtsever presented an invited in this area. This presents a of isotope hydrology in dam man- key note paper entitled “Overview of special challenge since the IAEA agement. Direct partners in this Nuclear Science and Technology in generally does not deal directly exercise are NGOs - in particular Groundwater Assessment/Management with the private sector. The main ICOLD - and international organi- and IAEA activities in the Gulf region” objective for the Agency’s strat- sations, in particular the World at the Fourth Gulf Water Conference egy must therefore be to bridge Bank. IAEA is preparing a the gap between the technology brochure on isotope techniques in held in Bahrain from 13 to 19 February providers and the problem- dam safety and sustainability, ad- 1999. The paper was also published in holders and to foster partnerships dressing questions that may be the proceedings of the Conference that will help achieve this objec- raised by the problem holders and which was organised by the Water Sci- tive. end-users, as well as an up-dated ence and Technology Association of the technical document dedicated to Gulf Countries and the Agency was a Thematic planning dam-related applications of iso- co-operation organisation in the meet- tope hydrology. ing. The implementation strategy con- Around 125 participants from the coun- sists of three interrelated compo- (3) Validation of promising appli- tries in the Middle East region took part nents: cations for future Technical Co- in the meeting and a total of 80 papers operation were presented in parallel sessions cov- (1) Problem Identification - Joint ering different aspects of water re- Missions Co-ordinated research pro- sources assessment, management and This component aims to grammes should be launched to planning. strengthen donor co-ordination, develop and validate methods The Conference was also informed of ensure that the Agency’s activi- which were identified as particu- the new regional TC project “Isotope Techniques for Improved Groundwater Utilisation - RAW/8/007” to be imple- mented during the 1999-2001 cycle with the main themes of assessment of recharge to aquifers / effectiveness of artificial recharge, and management of aquifers affected by salinity. It was recognised that these are problems of the highest priority in the region, and individual consultations and discus- sions were held with representatives Photo credit: B. Verhagen from several countries on their possible A major dam in Africa stands empty due to a leakage of participation in the regional project unknown origin. Tens of millions of dollars were spent pouring RAW/8/007. concrete at the base of the wall - a costly operation which did not solve the problem. General News

Quarterly No. 7, April 1999 - Page 4 WATER & ENVIRONMENT NEWS

ISOTOPE HYDROLOGY FOR WATER RESOURCES IN ARID AND SEMI-ARID REGIONS

Scientific Scope be fully integrated in water re- hydrological parameters for opti- sources development and manage- mum utilization of scarce water re- ment practice. sources. ack of fresh water for different uses (domestic, agricultural L Research and development efforts Currently, the Section is involved in and industrial) is presently hinder- devoted to isotope applications in 12 operational technical cooperation ing development in many parts of water sciences during the last projects in 25 Member States within the world. Water scarcity is most decades have resulted in proven the arid zone, four of which are acute in arid and semi-arid regions methodologies to be employed for a regional projects in Africa, West which cover almost one third of the wide spectrum of applications in Asia and the Arab- Peninsula (Fig. 1 Earth’s land surface. Moreover, water resources development and and Table 3). limited fresh water resources avail- management. The field often re- able in these regions are also ferred to as “Isotope Hydrology” is Support to Research Projects threatened with deterioration in presently recognized as a scientific quality due to man-induced hydro- discipline. The IAEA supplements field appli- logical changes. The available wa- cations with research programmes ter resources in arid regions are Methods based on the use of natu- on problems associated with water often restricted to groundwater. rally occurring isotopes are increas- resources assessment and manage- Surface flows are usually limited to ingly used in combination with other ment in arid and semi-arid areas and flash floods due to short duration hydrological methods for water re- where isotope techniques could pro- of high intensity rainfall events with sources development and manage- vide for a better understanding of very infrequent recurrences, which ment. The specific role and applica- the rather complicated behavior of have little potential as a source of tion areas of different isotopes in their aquifer systems. A Coordinated water. arid and semi-arid zone hydrology Research Programme (CRP) on are summarized in Table 2. “Isotope techniques in water re- Where availability of the renew- sources investigations in arid and able fresh water resources falls 3 A substantial amount of basic data semi-arid regions” to support the below 1000 m per capita per year, and results of applied field investi- research needs associated with wa- chronic water scarcity is observed, gations have already been pub- ter resources exploitation and man- and the lack of adequate water will lished on applications of different agement in arid regions involving be one of the main constraints on isotopes for the above cited hydro- Algeria, Egypt, France, Israel, the economic development and on hu- logical purposes in arid and semi- Russian Federation and the United man health and well-being. On the arid regions. Kingdom, was completed in 1998. basis of future population projec- The results of this will be published tions, it is anticipated that the total in the IAEA-TECDOC serie. Another population living in such water IAEA Support for Arid Zone CRP on “Isotope based assessment scarce regions will reach 2.8 - 3.3 Hydrology in Member of groundwater renewal and related billion by the year 2025. Countries States anthropogenic effects in water observing water scarcity at the pre- scarce regions” is being imple- sent and expected to be added into mented from 1995-1999, with the this category by 2025 are listed in Technical Assistance on Water participation of Austria, Bolivia, Table 1 (Egelman & Leroy, 1993). Resources Development projects China, Egypt, India, Jordan, Mexico, As can be noted from the Table, Nigeria, Saudi Arabia, Senegal, the majority of the countries facing The technical assistance of IAEA to South Africa, Syria, Tunisia and the problems of water scarcity at the Member States in arid zone hydrol- United Kingdom. This CRP will bring present and in the future are lo- ogy started in the early eighties in an understanding on mechanisms of cated in arid and semi-arid re- Africa, Latin America, West Asia infiltration and diffuse evaporative gions. and the Middle East. The main objectives of this assistance discharge for selected aquifers in In addition to problems related to through the technical cooperation Cont’nd on page 8 water quantity, deterioration of the programme are to contribute to and quality of the available limited wa- improve the assessment and pro- ter resources in arid and semi-arid tection of water resources in re- regions is also of great concern. In gions of water scarcity, in particular this regard, it is important that the in arid and semi-arid areas, and to scientific and technological ad- assist Member States in incorpora- vances made in the field of hydrol- ting isotope methods in routine practices for the determination of ogy during the past few decades Programme Review

Quarterly No. 7, April 1999 - Page 5 WATER & ENVIRONMENT NEWS

Table 1. Countries experiencing water scarcity (less than 1000 m3 of renewable water per person per year) in 1955, 1990 and 2025 (projected) [from Egelman & Le Roy, 1993, in Froehlich & Yurtsever, 1995]

Water scarce countries in 1955 Countries added to scarcity category in 1990

Bahrain Algeria Rwanda Barbados Burundi Saudi Arabia Djibouti Cape Verde Somalia Jordan Israel Tunisia Kuwait Kenya United Arab Emirates Malta Malawi Yemen Singapore Qatar

Countries added to scarcity category by 2025 (under all UN population growth projections)

Comoros Lybian Arab Jamahiriya Egypt Morocco Ethiopia Oman Haiti South Africa Islamic Republic of Iran Syrian Arab Republic

Table 2. Role and application areas of isotopes in arid and semi-arid zone hydrology (Froehlich & Yurtsever, 1995)

Recharge and discharge of groundwater resources Diffuse infiltration Saturated zone - 3H, freons, 36Cl, 14C (13C) dating Unsaturated zone - 3H profiles, bomb -36Cl and Cl- profiles - 2H, 18O - artificial tracers to study small scale processes Bank infiltration and other sources - 2H, 18O, 3H Exfiltration - 2H,18O profiles in the unsaturated zone Palaeohydrological applications Definition of time scales - 14C(13C), U/Th dating, 36Cl Palaeoconditions of aquifer replenishment - 2H, 18O (deuterium excess), 14C (13C) dating, noble gases (recharge temperature) Groundwater flow in large aquifers with various rock types - 87Rb/86Sr etc.. Anthropogenic impact on water resources Agricultural impact on groundwater - 2H, 18O - surface water infiltration, irrigation effects, salinization, 15N, 13C, 34S Urban impact on groundwater - 2H, 18O, 13C, 34S - leaking water distribution systems, waste disposal, industrial effluents - artificial tracers (e.g. labelled hydrocarbons) leachate migration and degradation Aquifer over-exploitation - 2H, 18O (salinization), 3H, 14C monitoring

Programme Review

Quarterly No. 7, April 1999 - Page 6 WATER & ENVIRONMENT NEWS

(Source: IAEA TC-Pride Database)

Figure 1 : Arid and semi-arid countries involved in IAEA technical cooperation projects (since 1976)

Table 3 : IAEA on-going Technical co-operation Projects related to arid and semi arid zone

Country Project Starting date Ethiopia Isotope techniques for water resources management 1999 Mali Use of isotopes in groundwater assessment 1999 Mongolia Isotope application in water resource management 1999 Morocco Isotopes in the sustainable management of water resources 1999 Namibia Improved monitoring of water flow distribution in Eastern 1997 Namibia Caprivi 1999 Niger Automatic tracer flow gauging stations in ephemeral rivers 1999 Pakistan Assessment of the water resources in the Zinder region 1999 Uganda Soil erosion and sedimentation studies 1997 Yemen Isotopes in assessment and monitoring of groundwater 1999 Chile Isotope hydrology investigation in the Sana’a region 1999 Algeria, Egypt, Contamination of water resources in semi-arid zone 1995 Ethiopia, Isotopes in groundwater resources development Regional Africa : Mali, Morocco, Niger, RAF/8/022 Nigeria, Senegal, Sudan 1999 Kenya, Madagascar, Sustainable development of groundwater resources Regional Namibia, South Africa, Africa : RAF/8/029 Tanzania, Uganda, Zimbabwe 1995 Iran, Jordan, Kuwait, Isotope hydrology techniques in water resources management Re- Lebanon, Saudi Arabia, gional West Asia Syrian Arab Republic., Turkey, 1999 United Arab Emirates, Isotope applications for improved groundwater utilization Re- Iran, Iraq, Jordan, gional West Asia Kazakhstan, Syrian Arab Republic Programme Review

Quarterly No. 7, April 1999 - Page 7 WATER & ENVIRONMENT NEWS the arid and semi-arid areas which Isotope Techniques on Arid Zone is necessary to undertake studies will provide valuable input to ma- Hydrology held in Vienna in 1978 using isotope techniques to solve nagement and protection of the re- were published in 1980 by the practical issues for the management source as well as develop the Agency. This publication showed in close partnership with water re- methodology of hydrochemical and that the most significant results sources planners. isotope profiles. achieved by using isotope tech- niques in arid zone hydrology con- The areas in which there is still a Manpower Development cern the occurrence and mecha- strong need for the application of nisms of modern and past isotope techniques are : Continuous efforts are being made recharge and the evidence of in- to develop manpower capabilities in terconnections between aquifers. - the assessment of recharge and Member States within the arid and The Agency has joined the UN- discharge (in arid zones, the amount semi-arid regions to apply isotope ESCO effort in the International of recharge actually reaching the techniques in water resources as- Hydrological Programme and has saturated zone is very limited and in sessment and management through contributed to the preparation and most cases the unconfined aquifers fellowships, workshops, seminars publication in 1989 of a “Critical are losing water by evaporation); and training courses. Training has Review on the use of environmen- tal isotope techniques in arid zone progressed from the basic aspects - the distinction between the rarely hydrology” in the UNESCO Tech- to advanced methods of geochemi- present recharged water resources nical Documents in Hydrology. cal modeling where isotopes are from those which are inherited from Two TECDOCs were published by integrated. Mechanisms of sharing previous humid climatic periods the Agency on isotope field appli- experience and expertise on arid (mining groundwaters); and semi-arid zone hydrology are cations for groundwater studies in the Sahel and in the Middle East, being developed through collabora- - the assessment of the efficiency of in 1993 and 1996, which provide tive efforts within regional projects water harvesting through artificial an in-depth analysis of isotope such as RAF/8/012 for Member recharge schemes, and States in the Sahel (1987-1992). results in the aquifer systems stud- ied as well as a basis for more - the anthropogenic impacts of agri- effective planning for future iso- Establishment of Laboratories cultural, industrial and urban activi- tope investigations in these two ties on water resources. Laboratories for isotope measure- regions. A third TECDOC present- ments as well as for chemical analy- ing the results of the CRP on the The increase of benchmark case ses were established or up-graded use of isotope techniques in water studies in the framework of regional in several Member States, inter alia resources investigations in arid projects and the wide popularization Algeria, Egypt, Iran, Jordan, Mo- and semi-arid regions, which was of their results through training and rocco, Niger, Pakistan, South completed in 1998, is being pre- mass media communication. Africa, Syrian Arab Republic, … un- pared by the Agency. der the different IAEA projects deal- Cheikh B. Gaye/IAEA ing with arid zone hydrology. Em- Future Outlook phasis is put on quality assurance References for chemical and isotopic analyses For several years, isotope tech- niques have being used in Mem- in the daily laboratory practice Froehlich K. & Yurtesever Y. (1995). Applica- through inter-comparison exercises, ber States in the arid and semi- tion of Tracers in Arid Zone Hydrology. IAHS both at the regional and inter- arid regions to solve problems Publ. n. 232, 3-10 regional levels. dealing with the availability and the quality of their water re- Dissemination of Information sources, but there is often lack of baseline data and no actual inte- The Proceedings of an Advisory gration of isotopic tools in ground- Meeting Group on the Application of water management. That is why it

Left : A site in North Senegal for Arid zone hydrology investi- gation using profiles in the unstu- rated zone (Photo credit : M. Daouad, UCAD, Senegal).

Right : Water scarce area in Namibia desert (Namib) also subject of IAEA’s activities (Photo credit : K. Froelich)

Quarterly No. 7, April 1999 - Page 8 WATER & ENVIRONMENT NEWS

INTERNATIONAL SYMPOSIUM ON ISOTOPE TECHNIQUES IN WATER RESOURCES DEVELOPMENT AND MANAGEMENT

he International Symposium on “Isotope Techniques in Water Resources Development and Manage- Tment” organised, by the International Atomic Energy Agency in co-operation with UNESCO, WMO and International Association of Hydrological Sciences was held in IAEA Headquarters, Vienna last 10-14 May, 1999. The Symposium was attended by 207 participants from 65 Member States and representatives of international organisations. Photo credit:C.Devia-Torres

The Sympo- sium Participants of the International Symposium on Isotope Techniques in provided Water Resources Developement and Management

an international forum for assessing the status and recent advances in isotope applications to water resources through three invited keynote speeches, 46 oral presentations and 98 poster presentations, on the following main themes:

· processes at the interface between the atmosphere and the hydrosphere; · investigations in surface and groundwaters: their origin, dynamics, interrelations; · problems and techniques to investigate sedimentation; · water resources issues : pollution, sources and transport of contaminants, salinisation, water-rock interaction and processes in geothermal systems; · isotope data interpretation and evaluation methodologies : modelling approaches.

A round table discussion during the Symposium reflected that isotope applications contribute substantially to various hydrological problems encountered in water resources assessment and management. It was subsequently stressed that isotopes should be an integral part of the routine investigations related to utilisation of water resources and protection to achieve the ultimate goal of sustainable development. In this regard, the envisaged future International Programme to be initiated by the Agency on “Isotopes in the Hydrological Cycle”, to be implemented jointly by UNESCO and WMO, was strongly endorsed.

The proceedings of the Symposium will soon be published by the Agency as a CD-ROM.

For further information, please contact the Symposium’s Scientific Secretary, Mr. Yuecel Yurtsever, Section of Isotope Hydrology, IAEA.

Quarterly No. 7, April 1999 - Page 9 WATER & ENVIRONMENT NEWS Groundwater problems studies in the Thar desert, India using isotope techniques

mate recharge rate to the aquifer. If modern recharge is Introduction absent, groundwater dating using radiocarbon could help to identify old groundwater or paleowaters. A num- ber of isotope studies carried out in arid zones he Thar desert extends from the western side of (particularly in the Sahara) have shown that the deep the Aravalli mountain ranges in India upto the T groundwater is generally very old. From these studies it limit of Indus valley in Pakistan. It covers 60% of was concluded that episodic large scale recharge corre- the area of the Rajasthan state in the north western sponding to humid phases or pluvials occurred in these part of the country. With ~ 38% of the state’s 2 arid areas. The paper reviews our experiences on the population with a density of 84 persons/km , this is application of isotope techniques in understanding one of the most populated desert regions of the groundwater recharge process in arid western Ra- world. The constantly increasing human and live- jasthan. stock population is putting tremendous pressure on the available natural resources (Figure 1). Groundwater recharge process

The possible groundwater recharge process in arid ar- eas like Rajasthan may be :

a) direct recharge of precipitation through the unsatu- rated zone b) indirect recharge through river channels from flash floods or from irrigation canals etc. c) paleoclimatic recharge during humid episodes in the past which was mentioned above.

Direct recharge of precipitation to the groundwater was studied in Jodhpur and Barmer districts of western Rajasthan using artificial 3H tracer as HTO in the unsatu- rated zone (Shivanna et al 1994). The results showed that the tracer displacement and hence the groundwater was found to be negligible due to low rainfall (~ 200 to 300 mm) during the study periods of 1982-84 and 1990-92 respectively. Hence for arid areas the artificial Figure 1 Location map of the study areas tracer method which determines recharge on an annual basis for a short duration may not be useful and may be The land is characterised by sand dunes with inter- combined with other methods such as environmental 3H, dunal plains in the north, west and south, and 36Cl and chloride methods. In these methods results are alluvium in the central and eastern parts. Streams derived from long term average of recharge. In central are very few, ephemeral in nature and confined Sudan for example (mean annual precipitation = 180 mostly to the rocky parts of the desert, the most mm) a net annual direct recharge of around 1 mm/a was prominent being the Luni river in the southwest estimated using the chloride method (Edmunds et al region. Precipitation is low and erratic with frequent 1990). In a study being carried out under an IAEA/CRP droughts. on isotope based assessment of groundwater renewal and related anthropogenic effects, environmental chlo- The main source of water in the area is groundwa- ride profiles in a site in Barmer district of western ter. The region faces acute shortage of potable Rajasthan (Mean annual rainfall = 241 mm), showed a water and village women have to fetch water from mean annual recharge of 14 mm. The recharge ob- many kms away to meet domestic requirements. In tained by the chloride method is being compared with many places the groundwater is brackish or saline. that of the tritium method. Unsaturated zone solute and Efforts are being made by the state groundwater isotope profile will also be used to provide a record of department to study known groundwater resources recharge history as interpreted for profiles from Cyprus and explore potential ones in the region. and northern Senegal (Cook et al 1992).

In groundwater management, particularly in arid In arid areas, indirect recharge through wadis (river regions like western Rajasthan, it is important to channels) could be an important mechanism for ground- know the presence of modern recharge and to estimate the recharge rate to avoid over- exploitation of the groundwater resource. Isotopes can help to identify modern recharge and to esti- Technical Review

Quarterly No. 7, April 1999 - Page 10 WATER & ENVIRONMENT NEWS water recharge (Gonfiantini 1974, Darling 1987). rary works and known to have existed before 3000 Environmental isotopes (2H, 18O, 3H) and 14C were years BP. The shallow groundwaters along the river employed to identify the recharge process in the course have negligible 3H and low 14C values of 54 to Jalore area of western Rajasthan (Navada et al 70 pmc confirming that they are old waters. 1993). The isotope results showed that most of the shallow groundwater near the Sukri river course, An environmental isotope study in the Bhadka- have ð2H and ð18O enriched compared to the shal- Bheemda area in Barmer district in western Rajasthan low groundwater away from the river course and (Navada et al 1996) showed that the deep groundwa- have 3H values of 15-20 TU, showing that they are ter (depth > 100 m) has depleted ð2H, ð18O compared possibly recharged from river channels during flash to the shallow groundwater and present day precipita- floods. The deep groundwater (>100 m) near the tion. They have negligible 3H and 14C model ages of river course also shows some component of recent these groundwaters range from 4000 to 9500 years recharge indicating probable interconnection be- BP. Hence they are paleowaters recharged in the tween the shallow and deep aquifers. The other deep past. groundwaters away from the river course on the other hand have negligible 3H and depleted ð2H and ð18O, indicating recharge during more humid periods in the past.

Paleo- co- logical stud-

Figure 4 Deuterium and Oxygen-18 relationship of samples from Bhadka-Bemda area ies have proposed the following dry and wet periods in Rajasthan (Bryson and Barreis 1967, Singh et al Figure 2 Deuterium and Oxygen-18 relationship 1974). of samples from Jalore area 10,000 - 6000 years BP moderately humid, rain fall greater than present 5000 - 3000 years BP humid period 3000 - 1100 years BP low rainfall 1100 - Present dry conditions

Hence the recharge to these groundwaters occurred during humid periods shown above. Effect of over exploitation of groundwater

Bur The increasing demand of water supply for various ied purposes has lead to heavy exploitation of groundwa- co ter resources in many parts of the world. This is particularly so in arid regions where limited water Figure 3 Depth versus Deuterium plot resources are being exploited with adverse effects of of samples from Jalore area rapid lowering of water table and deterioration of water quality. For example in Bikaner town in Western urses of rivers (paleochannels) are important as they Rajasthan the aquifers are being extensively used have good groundwater potential. Isotope studies and the water levels have been declining. An isotope were carried out along a buried river course in Jaisalmer district in western Rajasthan, which was supposed to belong to the legendary Saraswati river of Himalayan origin mentioned in many earlier lite- Technical Review

Quarterly No. 7, April 1999 - Page 11 WATER & ENVIRONMENT NEWS study (Navada et al 1996) showed that the shallow and deep wells have generally similar d2H, d18O and Bryson R.A., & Berreis D.A. (1967). Bulletin American Meteorologi- negligible 3H. The 14C model ages of the deep wells cal Society Boston, 48, 136. Cook P.G., Edmund W.M., Gaye C.B.(1992). Water Resources vary from modern to 9500 years BP. Similar, d2H, 18 Research 28 (10), 2721. d O of the shallow and deep groundwater and Darling W.G. Edmunds W.M., Kinniburg D.G.,and Kotoub S. (1987). young groundwater encountered in some deep well In : Proceedings of IAEA Symp.,Vienna. Isotope techniques in water samples indicates mixing of the shallow and deep Resources Development, 205. Edmunds W.M., Darling W.G.,and Kinniburg D.G. (1990). In: zone waters due to heavy exploitation of groundwa- Groundwater Recharge (e.d. D.N.Lerner, A.S. Issar and I.Simmers) ter in the area. Verlag Heinz Heise, Germany, 257. Gonfiantini R.Dincer T., and Devekoy A.M. (1974). In : Proc. of IAEA In an another example, in a limestone belt which Symp. Vienna. 1, 293 extends from Bilara to Phalodi in Western Ra- Nair A.R., Sinha U.K, Joseph T.B., and Navada S.V.(1993). Proc. 2nd National symp. on Environment,Jodhpur, 188 jasthan, groundwaters are being heavily exploited Navada S.V., Nair A.R., Rao S.M., Paliwal B.C. and Doshi C.S. for irrigation and domestic purposes. The isotope (1993). J. Arid Environment 24, 125 results (Nair et al 1993) show that modern recharge Navada S.V., Nair A.R., Rao S.M.,Kulkarni U.P., and Joseph T.B., is possible in the southern part of the area through (1996). In: Isotopes in Water Resources Management Proc.IAEA Symp.Vienna, 451 the Luni river which is ephemeral. In the central part 3 14 Shivanna K,. Kulkarni U.P., Sinha U.K., Nair A.R. and Navada S.V. the groundwaters have negligible H, and C indi- (1994) In : Proc.International workshop on groundwater monitoring cates an age of ~ 2000 years BP. In Phalodi area in and recharge in semi arid areas, Hyderabad , 61 the north, the groundwater contains negligible 3H Singh G., Joshi R.D., Chopra S.K., Singh A.B., (1974). Phil. Trans. and 14C showing a maximum age of 4000 years Royal Soc. London B. Biol. Sciences 267, 889. indicating paleo recharge. Time series analysis of S.V.Navada the tritium data of some of the wells showed a Isotope Applications Division, decreasing trend. This may be due to over- exploita- Bhabha Atomic Research Centre, tion of groundwater in the central part leading to Mumbai,India influx of older water from the north.

Thus, isotope techniques are useful in understanding groundwater recharge process in arid areas. Ab- sence of modern recharge and over exploitation observed in some of the above studies stress the need for proper management of such scarce ground- water resources.

References : Technical Review GROUNDWATER RENEWAL IN WATER SCARCE REGIONS

he second Co-ordination Meeting of the Co- for successful completion of the CRP in 1999. Tordinated Research Project (CRP) on "Isotope -Based Assessment of Groundwater Renewal and Significant progress was reported in most of the Related Anthropogenic Effects in Water Scarce country projects. Spatial variability was an important Regions" was held from 9-13 November 1998 in question discussed at some depth. The long-term Sfax, Tunisia. recharge rates provided by the unsaturated zone Cl profiles and supported by the 3H, 2H and 18O data The CRP involves applied field research for study offered by far the best and most robust point source of the infiltration rate (natural recharge) and/ or data for large areas of the semi-arid regions of the diffuse evaporative discharge under natural condi- world. However these need to be integrated on a tions, through hydrochemical and isotope profiles regional scale. Additional work required and tasks to at selected benchmark representative sites in arid be accomplished during the last year of the project and semi-arid regions. Institutions from fourteen have been identified. countries (Austria, Bolivia, China, Egypt, India, Jordan, Mexico, Nigeria, Saudi Arabia, Senegal, It was agreed that the overall data and results be South Africa, Syria, Tunisia and United Kingdom) compiled in a TECDOC to be published by the are participating in this CRP. Agency after the completion of the CRP.

The meeting reviewed the results and achieve- The Responsible officer of this CRP is Y. Yurtserver. ments of the work undertaken since the last co- ordination meeting held in Vienna on December 1997. In depth discussions were held on various related technical/ scientific issues concerning the results achieved, as well as further required work CRP News

Quarterly No. 7, April 1999 - Page 12 WATER & ENVIRONMENT NEWS ISOTOPE TECHNIQUES FOR WATER RESOURCES IN THE ASIA AND PACIFIC REGION sotopic techniques are not yet · Absence of appropriate univer- tion between practising hydro- Iwidely used in practice to tackle sity curricula and post-graduate geologists and isotope scien- major water resources issues in training courses in isotope tists, in the framework of the the Asia and Pacific region. This hydro-logy. National IHP committees was the main conclusion of the (International Hydrological Advisory Group Meeting (AGM) on From presentations on water re- Programme of UNESCO for " The Integration of Isotope Tech- sources development and manage- example). niques in Water Resources Investi- ment issues in their respective · Help to strengthen existing an- gations in the Asia and Pacific countries, three priority areas were alytical facilities and their use Region”, which was held in identified, as common to most of at the regional level. Kozhikode (India) during 2 to 5 the countries in the region, where · Support and extend assistance November 1998. The meeting was the use of isotopes would be very for training of practising hydro- attented by representatives of wa- helpful and would make a strong geologists in isotope hydrol- ter resources agencies in India, impact on the current practice of ogy. Korea, Malaysia, Myanmar, Sri water resources development and · Develop a practical guide for Lanka and Thailand. management : the use of isotope techniques in hydrology, and a guidebook The participants found that the · Assessment of groundwater re- on the various requirements principal constraints which prevent sources in different hydrogeolog- and procedures for sample col- full integration of isotope with other ical environments; lection for isotope analyses. hydrological techniques are, · Evaluation of the impact of artifi- · Facilitate the inclusion of a among others: cial recharge on groundwater re- course in isotope hydrology in sources; university curricula, or at least · Non-existent or minimal inter- · Erosion and sedimentation in introductory topics on isotope action between practising hy- lakes, reservoirs and coastal hydrology in courses on drogeologists and isotope sci- areas. groundwater hydrology, hydro- entists in most of the countries geology, geophysics, water in the Region; The participants recommended quality, etc. · Insufficient facilities for isotope that the Agency undertake the fol- analyses; lowing activities to promote the in- · A lack of sufficient training for tegration of isotope techniques into field hydrologists in the use and hydrological practice in the region : application of isotope tech- niques; · Encourage better communica- ISOTOPES FOR IMPROVED DRINKING WATER RESOURCES MANAGEMENT workshop aimed at assessing the factors af- The workshop came to the conclusion that the main Afecting implementation of the project RAS/ factors affecting the implementation of RAS/8/084 8/084, “Isotope Applications for Improved Drinking are : Water Resources Management” was held on 3 and 4 December 1998, in conjunction with the UNDP/ · Need to define the hydrological problem to be IAEA/RCA Regional Field Training Course on solved bearing in mind the required end result which “Application of Isotope and Chemical Techniques is to provide access to drinking water supply in the to Groundwater Problems”, held at the Bhaba area Atomic Research Centre, Mumbai, India, from 30 · Need to pursue the active involvement of the November to 4 December 1998. water resource agency which is the end user of the results of the project. The objectives and implementation programme of · Need to identify suitable counterparts to imple- the project were presented by Jane Gerardo- ment field investigations and generate an adequate Abaya, from IAEA. The national hydrological prob- well interpreted conceptual hydrogeochemical model lems for each participating country to be included of the study area. in the field investigation under the project were · Need to assess the quality of analytical results of discussed with counterparts from China, India, water chemistry. Indonesia, Malaysia, Philippines, South Korea, Sri Lanka, Thailand and Vietnam and with experts from Australia, New Zealand and Philippines. Review of Activities

Quarterly No. 7, April 1999 - Page 13 WATER & ENVIRONMENT NEWS

The workshop also admitted that differences of experience exist among the concerned countries. · to carry out technical missions in the participating Some countries have limited experience in the countries to address the issues of participation of application of isotopes, while others require assis- end users, definition of the problem and formula- tance to attract the collaboration of end users. tion of work plan for the overall field work re- These issues would require the direct involvement quired including isotope investigations. of the Agency through technical missions to Mem- · to organise an inter-laboratory comparison for ber States. chemical results during the second quarter of To the Agency the participants recommended : 1999.

SUSTAINABLE DEVELOPMENT OF GROUNDWATER RESOURCES : A NEW REGIONAL MODEL PROJECT FOR AFRICA

he first coordination meeting of the regional Tmodel project RAF/8/029 for Southern and The most significant conclusions of the meeting Eastern Africa was held in Vienna, Austria, from were: 22 to 26 February 1999. The meeting was at- tended by representatives from six participating - Equipment provided under the project will include countries. a liquid scintillation apparatus for the Schonland Research Center (SRC) who will serve as regional The main objective of the meeting was to prepare laboratory and field equipment/supplie to support refined national project proposals; budgets and national project activities. The IAEA will also pur- schedules for the national efforts, within the sue outside resources to fully upgrade the SRC framework of the project funding as approved by labs in the best interests of the regional program. the Board of Governors (BoD); and to develop work plans for the first year of project implementa- - A US contribution of $100,000 has been allo- tion detailing, support from IAEA and necessary cated to the project for 1999 and planned addi- national inputs. tional contributions of $100,000 will be made in 2000 and 2001. A presentation made by representatives of IAEA on the scope and budget for the model project - The LSA in Tanzania is now in operation. In 1999 RAF/8/029, as approved by the BoD, was followed it will primarily be tasked with analyses for the by discussions on strategies for integrating the national project, but should be available for re- model project with national priorities and water gional support in the future. sector efforts under way through other channels so as to - Channels of communication will be developed by everage IAEA assistance. The national hydrologi- the IAEA to facilitate communications between cal and hydrogeological problems for each partici- project partners. pant country to be included in the field investiga- tion under the model project were discussed with - A manual for isotope applications in water re- counterparts representing : Madagascar, Namibia, sources assessment will be developed under the South Africa, Tanzania, Uganda and Zimbabwe. project. One possibility is to produce the manual as an IAEA TECDOC in the second or third year of The effectiveness and the efficiency of the imple- the project with the help of project consultants. mentation of the model project will depend on the Planning and initial efforts for this manual should following : get under way as soon as possible to ensure its completion within the scope of the project. early planning of isotope investigations, The responsible technical officer is Cheikh B. wider constituencies, in order to direct efforts to Gaye. end users,

more direct contact between IAEA and the water sector,

Need for better communication between project partners.

Review of Activities

Quarterly No. 7, April 1999 - Page 14 WATER & ENVIRONMENT NEWS TRAINING COURSE ON CHEMICAL MODELLING

regional training course on Geochemical and isotop hydrology investigations are most effectively AIsotope Modelling was organised within the used to estimate parameters for use in hydrologic framework of the ongoing regional TC project RAF/ models and to verify the results of hydrologic mod- 8/022 and held from 28 November to 9 December els. Depending upon the nature and amount of at the Research Institute for Groundwater, National isotope data collected in a given study, geochemical Water Research Centre, Cairo, Egypt. The Course models may be used to derive from the isotopic was attended by 29 participants from the 9 coun- data, hydrologic parameters and constraints that can tries involved in the regional project, namely Alge- be used in hydrologic modelling. ria, Egypt, Ethiopia, Mali, Morocco, Niger, Nigeria, Senegal and Sudan. The training course in Cairo, therefore, focused on the hands-on use of geochemical models The course was organised in response to the SOLMINEQ.88 and NETPATH. These models are strong requests made by the countries participating commonly used for studies related to groundwater in the RAF/8/022. It was recognised that the devel- systems. The course emphasised a brief theoretical opment and management of groundwater re- introduction followed by actual use of the modelling sources generally is optimised by using computer codes by the participants. The participants were models of aquifer systems. These hydrologic mod- encouraged to use the models with their own data els such as MODFLOW commonly used for derived from the RAF project. aquifers in porous media, provide an understand- ing of the aquifer systems under natural conditions Judging by the interest shown by the participants in and under various levels of resource exploitation. the actual use of the models, including that with their But they require information on the geology and own data, the course was quite successful in building groundwater hydrology, which is developed capacities in the use of geochemical models. The through extensive geologic and hydrologic investi- feedback received from the participants indicates gations in the field as well as in the laboratory. that the course was quite successful in meeting its There exists, however, a great amount of variabil- objectives. It is recommended that similar courses ity in the geologic and hydrologic properties which should be conducted in the future at the country makes the task of hydrologic modelling quite diffi- level in order to disseminate the information more cult. Isotope hydrology techniques provide inte- widely. grated information on the source and quantification of recharge and the results of hydrologic processes controlling the groundwater system. The results of

ISOHIS DATA BASE

he Isotope Hydrology Section is establishing The system will consist of three components: Tan information system to gather, store and · software for entering records, to be used by disseminate chemical, isotopic and geographical counterparts in Member States; data from isotope-hydrological sites around the · software for entering and verifying records, to be world. This system is referred to as the Isotope used by the Isotope Hydrology Section; and Hydrology Information System (ISOHIS). · a Web site for querying the database, to be used by registered users from the general public. The objectives of ISOHIS are: · to facilitate data communication between coun- The database will contain the following: terparts of TC projects and the IAEA. · summary information about the project; · to save, store and facilitate easy access to data · basic information about the samples taken; gathered during more than 30 years of IAEA · data on the concentrations of the major and minor isotope hydrology studies. ions, trace constituents, isotopes, dissolved · to integrate the highest possible proportion of gases measured in water, and relevant hydrologi- existing and new, high quality data in a common cal, hydrogeological, geographical data collected database. in the field; · to provide data to IAEA RC and TC projects as well as other national and international projects. The software for entering records and the user · to assist in developing local and regional manual can be downloaded from ftp:// databases ftp.iaea.org/dist/isohis/. The file name is : ih- · to give recognition to and highlight the role of scp10.exe . This is a self-extracting file. the data providers. The Web site will be open to the General Public soon.

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ISOTOPE HYDROLOGY CALENDAR

October RCM on “Radionuclide Transport Dynamics in Freshwater Re- CM on IAEA/UNESCO Teaching sources”. material in Isotope Hydrology. Final assessment meeting of the 1999 4-8, RCM on “Isotope Techniques to TC project on “Geothermal Energy Study Soil Erosion and Sedimenta- Resources and Environment Man- IAEA MEETINGS AND TRAINING tion in Lakes and Reservoirs, Phase agement”, Indonesia (RAS/8/075) II” September Barcelona, Spain IAEA Meeting Categories RCM on Isotope techniques for the RCM on “Isotope-based Assess- assessment of slow moving deep ment of Groundwater Resources” AGM: Advisory Group Meeting groundwater and their potential ap- Vienna, Austria RCM: Research Co-ordination plication for the assessment of Meeting waste diposal. November CS: Consultants Service Bern, Switzerland CM: Consultants Meeting RCM on “Isotope response to dy- SYM: International Symposium AGM - Prepare a technical docu- namic changes due to long-term ex- ment on the state of the art in ploitation in groundwater systems” GC/CF-IRMS Vienna, Austria

Staff Changes in the Isotope Hydrology Section working for two years in the Isotope Hydrology Section. As a temporary assistant professional in isotope geochemistry, his activities were mainly related to the efforts of the Section to enhance the transfer of know-how and technology in isotope hydrology to developing member states. He was in charge of “Water & Environment News” and was involved in activities related to the GNIP database and ISOHIS. Departure: Dr. Pang has resumed his previous job in China as a research scientist in isotope hydrology.

ERRATA He can be contacted at the following address Laboratory of Geothermics The cover photo of issue No 6 was erro- Institute of Geology neously captioned. It is actually well AH-6 in Chinese Academy of Sciences Ahuachapan Geothermal field, El Salvador. P.O. Box 9825, Beijing 100029 We apologize for this error. China email: [email protected] Dr. PANG Zhonghe left the Agency in early April after 99-00301 Water and Environment News, Isotope Hydrology Section, International Atomic Energy Agency, Wagramer Strasse 5, P.O.Box 100, A-1400, Vienna, Austria. Printed by IAEA in Vienna

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