Two volumes, Publs 280 & 281, resulted from the International Symposium on: Water Resources Systems—Global Change, Risk

Assessment and Water Management held during IUGG 2003 (Sapporo, Japan).

The provision of adequate water supply is of fundamental importance to social and economic security worldwide. In many regions, the awareness of the wider community of the importance of water resources management has increased dramatically over the past few years. It has become clear that, in order to sustainably balance supply and demand of natural resources, the integration of a range of disciplines from a comprehensive systems perspective is essen-tial and this certainly applies to water. The call for contributions to this symposium was so suc-cessful that it was expanded and so the selected papers were divided, according to topic, be-tween two books, IAHS publications 280 and 281.

Water Resources Systems–Hydrological Risk, Management and Development (Publ. 281) edited by Günter Blöschl, Stewart Franks, Michio Kumagai, Katumi Musiake & Dan RosbjergPubl. 281 (2003) ISBN 1-901502-32-5; 266 + x pp. Price £60.30

As a result of contamination issues, land-use changes and global climate fluctuations, water availability ap-pears to be decreasing in many regions. At the same time, dealing with the risk associated with extreme events—be it floods, droughts or other hazards—has become an integral part of the management and devel-opment of any water resources system, both in short-term operations as well as in the long-term planning of water resources. This volume addresses (see over for contents):

– Flood risk: analysing trends and processes, – Modelling flood runoff, – Drought risk: analysing trends and processes, – Management of reservoir systems, – Water resources management policies, – Water resources management: methods and case studies, – Integrating water resources management.

Contents

Preface by Günter Blöschl, Stewart Franks, Michio Kumagai, Katumi Musiake & Dan Rosbjerg

v

1 Introduction

Water Resources Systems—Hydrological Risk, Management and Development: A Summary Günter Blöschl

3

2 Flood Risk: Analysing Trends and Processes

The impact of climate variability on flood risk Anthony S. Kiem & Stewart W. Franks

11

Frequency of catastrophic climatic phenomena in Ukraine under the influence of global warming Svetlana G. Boychenko

18

Could global warming have caused the most recent floods on the Tisza River? András Bárdossy, István Kontur, Jiri Stehlik & Gábor Bálint

26

Extreme precipitation and floods in the changing world Zbigniew W. Kundzewicz

32

Testing trends in annual maximum discharge series in Israel Arie Ben-Zvi & Benjamin Azmon

40

Regional flood risk—what are the driving processes? Ralf Merz & Günter Blöschl

49

Comparison of maximum precipitation estimates with runoff depths for the 1342 and 2002 Central European flood events Gerd Tetzlaff, Michael Börngen, Manfred Mudelsee & Armin Raabe

59

3 Modelling Flood Runoff An approach to creating lumped-parameter rainfall–runoff models for drainage basins experiencing environmental change Earl Bardsley & Suxia Liu

67

Data assimilation in the MIKE 11 Flood Forecasting system using Kalman filter-ing Henrik Madsen, Dan Rosbjerg, Jesper Damgård & Frands Søbjerg Hansen

75

A “consensus” real-time river flow forecasting model for the Blue Nile River Asaad Y. Shamseldin & Kieran M. O’Connor

82

Flood forecasting and management in Pakistan Shaukat Ali Awan 90

Risk assessment for closure of the diversion channel at the Three Gorges Project on the Yangtze River Caijun Wang, Shenglian Guo, Xiangrong Tian &Yonghua Zhu

99

Application of dynamic-stochastic runoff generation models for estimating ex-treme flood frequency distributions L. S. Kuchment, A. N. Gelfan &

107

V. N. Demidov

Decision support system for flood control and ecosystem upgrading in the Red River basin M. J. Booij

115

Flood control—environmental and socio-economic issues: case study of a diver-sion area in Vietnam Phan Thi Anh Dao & Takara Kaoru

123

4 Drought Risk: Analysing Trends and Processes Effects of forest restoration in mountainous basins on the long-term change in baseflow recession constants Junji Shimokura & Hirofumi Shibano

133

Impact of climate on flow regimes of the upper reaches of streams Hironobu Sugiyama, Varawoot Vudhivanich, Andrew C. Whitaker &Kosit Lorsirirat

141

Did sulfur-rich volcanic eruptions affect drought episodes in Taiwan? Fong-Chiau Chang & Chung-Ho Wang

148

Assessment of the impact of climate and ecosystem changes on drought condi-tions: case study from Romania Gheorghe Stancalie, Simona Catana, Ion Poiana, Anisoara Iordache & Vasile Craciunescu

158

Elevated drought risk due to multi-decadal climate variability Anthony S. Kiem & Stewart W. Franks

165

5 Management of Reservoir Systems

An optimization model for reservoir systems to assist in coping with changes in demand and supply conditions Carsten Brass & Andreas H. Schumann

175

Water allocation for multiple uses based on probabilistic reservoir inflow fore-casts Sankar Arumugam, Ashish Sharma & Upmanu Lall

184

Improved heuristic reservoir operation using control curves incorporating the vulnerability norm Adebayo Adeloye, Athanasios Psarogiannis &Majid Montaseri

192

Optimal short-term operation of a multipurpose reservoir system under limited water supply Antonio Cancelliere, Giuseppe Giuliano, Vincenzo Nicolosi & Giuseppe Rossi

200

Evaluation of alternate objective functions for optimal operation of an irrigation reservoir under a multi-crop environment N. V. Umamahesh

208

Simulating the discharge of the Chao Phraya River taking into account reservoir operation Naota Hanasaki, Shinjiro Kanae, Katumi Musiake & Taikan Oki

215

6 Water Resources Management Policies

Large dams—a contribution to sustainable water and energy development? Elke Petersson & Manfred W. Ostrowski

227

India’s national water policy and water management K. S. Murty 233

Towards a new paradigm for integrated water resources management and devel-opment in Indonesia Joesron Loebis

240

Proposed soil and water conservation strategies for Lake Rawa Dano, West Java, Indonesia Seno Adi

248

7 Water Resources Management: Methods and Case Studies Environmental flow requirements in water resource planning and operation Denis Hughes

261

Integrated water resources management under complex hydro-political condi-tions: the Palestinian case study Ayman Rabi, Abdellatif Khaled & Natasha Carmi

269

Impact of the Gurara River (Nigeria) interbasin water transfer scheme on the Kaduna River at the Shiroro Dam O. D. Jimoh & O. S. Ayodeji

277

Effects of climate change on irrigation activities: a case study of the Benin-Owena River basin irrigation projects Catherine I. Ikhile & George U. Ikhile

287

A simulation study of infiltration facility impact on the water cycle of an urban catchment Srikantha Herath, Katumi Musiake & Sadayuki Hironaka

294

Method for satellite monitoring of water storage in reservoirs for efficient re-gional water management Jun Magome, Hiroshi Ishidaira & Kuniyoshi Takeuchi

303

8 Integrating Water Resources Management Sustainability and groundwater Hugo A. Loáiciga 313

Water management budget as a basis for assessing water priorities in a catchment Boris Fashchevsky & Tatyana Fashchevskaya

322

A system for ecological and economic assessment of the use, preservation and restoration of urban water bodies: St Petersburg as a case study Sergei Kondratyev

327

Sustainable water resources management in the Dragonja catchment, Slovenia Mitja Brilly & Lidija Globevnik

334

The Chinese water resource: managing increasing demand and natural variations Jianping Yang, Yongjian Ding & Rensheng Chen

341

Impact of population growth and climate change on the quantity and quality of water resources in the northeast of India U. C. Sharma

349

World water use and water availability: trends, scenarios, consequences Igor A. Shiklomanov & Jeanna А. Balonishnikova

358

Key word index 365

Preface

In many regions of the world, the awareness of the wider community of the importance of water resources management has increased dramatically over the past few years. It has become increasingly clear that, in order to sustainably balance supply and demand of natural resources, the integration of a range of disciplines from a comprehensive systems perspective is essential and this certainly applies to one of our most precious resources: water. As a result of contamination issues, changes in land-use patterns and global climate fluctuations, water availability appears to be decreasing in many regions, contrasted by an increase in water demand as a result of a growing population and changes in the global economy. At the same time, dealing with the risk associated with extreme events—be it floods, droughts or other hazards—has become an integral part of the management and development of any water resources system, both in the short-term operation as well as the long-term planning of water resources.

During the 2003 General Assembly of the International Union of Geodesy and Geophysics, 30 June–11 July 2003 in Sapporo, Japan, a symposium was held entitled: Water Resources Systems—Global Change, Risk Assessment and Water Management. The Symposium was organized by the International Commission on Water Resources Systems, ICWRS, of the International Association of Hydrological Sciences, IAHS, together with other IAHS commissions.

The broad coverage and the multi-faceted nature of the subject area were reflected in the large number of contributions to the symposium drawn from a range of disciplines. The paper proceedings from this symposium have been compiled into two volumes. A companion volume (IAHS Publ. no. 280*) focuses on water availability while the present volume focuses on hydrological risk and water management. The first paper in this volume provides a summary of the contributions published here.

The editors gratefully acknowledge the assistance of a number of reviewers in bringing together this volume including Adebayo Johnson Adeloye, Sankar Arumugam, Earl Bardsley, Arie Ben-Zvi, Martijn J. Booij, Abdel-Azim M. Ebraheem, Denis Hughes, Zbigniew W. Kundzewicz, Hugo A. Loaiciga, Umamahesh V. Nanduri, Asaad Y. Shamseldin, Ashish Sharma, Igor A. Shiklomanov, Hironobu Sugiyama, and Caijun Wang. Many thanks to Cate Gardner from IAHS Press for her professional approach and all the help with the processing of the manuscripts.

Editor in chief:Günter Blöschl

Vienna University of Technology, Austria

Co-editors:Stewart Franks

University of Newcastle, AustraliaMichio Kumagai

Lake Biwa Research Institute, Uchidehama Otsu, JapanKatumi Musiake

University of Tokyo, JapanDan Rosbjerg

Technical University of Denmark, Lyngby, Denmark

*Available from IAHS Press: Water Resources Systems–—Water Availability and Global Change, edited by Stewart Franks, Günter Blöschl, Michio Kumagai, Katumi Musiake & Dan Rosbjerg. IAHS Publ. no. 280.

_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 3–8.

Water Resources Systems—Hydrological Risk, Management and Development: A Summary

GÜNTER BLÖSCHLInstitut für Hydraulik, Gewässerkunde und Wasserwirtschaft, Technische Universität Wien, Karlsplatz 13/223, A-1040 Wien, Austria bloeschl@hydro.tuwien.ac.at

INTRODUCTION

This volume contains 43 contributions authored by experts from 31 countries which is certainly a reflection of the importance of management and risk issues in water resources in many parts of the world. The publication has been organized into seven topics. The following is a brief summary of the main themes and results of the individual contributions, highlighting the overall findings of the symposium as far as hydrological risk and water management are concerned.

FLOOD RISK: ANALYSING TRENDS AND PROCESSES

The first set of papers relates to flood trends and flood processes. Kiem & Franks analyse temporal trends of flood risk across southeast Australia and relate flood occurrence to climatic indicators. They find that La Niña events are the dominant drivers of elevated flood risk and that an Inter-decadal Pacific Oscillation index is significantly related to multi-decadal epochs of elevated flood risk. These results point to the non-stationarity of flood risk and hence have marked implications for achieving robust flood estimates. Boychenko analyses the long-term trends of floods, droughts and other climatic anomalies and relates them to a number of causative factors. She finds that most of the anomalies are closely related to temperature fluctuations which allows her to construct a regression model to represent future scenarios associated with possible climate change. A similar analysis of climate factors is provided by Bárdossy et al. who analyse flood peaks of the River Tisza, Hungary, where most of the largest flood peaks of a 100-year record have occurred during the past four years. Large-scale atmospheric circulation patterns show non-stationary behaviour suggesting they are a possible explanation for the increase of floods in the Tisza basin although the results are not univocal. Kundzewicz takes a wider perspective of the same problem, analysing flood trends around the world. He finds that, in many places, flood risk is likely to grow due to a combination of anthropogenic and climatic factors although there are numerous counter-examples. A more prevalent finding is an increasing vulnerability to floods. This is consistent with the results of Ben-Zvi & Azmon who examine temporal trends in flood peaks in a number of regions in Israel. Except for one region, the changes are of local extent, if any. In some catchments flood peaks appear to increase, but they appear to decline in others.

While these contributions focus on isolating temporal trends and relating them to climatic indicators, the following two contributions examine individual flood processes more closely. Merz & Blöschl propose a framework for identifying the causative mechanisms of floods at the regional scale. They test the framework on flood data in Austria and are able to stratify the flood peaks into long-rain floods, short-rain floods, flash floods, rain-on-snow floods and snow-melt floods. All the flood types exhibit pronounced seasonal patterns and their relative contribution changes with flood magnitude. Tetzlaff et al. analyse the causative factors of two major flood events in Germany, the 1342 and the 2002 floods, by relating results from a dynamic precipitation model to observed (or estimated) flood discharges, which allows them to back-calculate the most important hydrological characteristics of the flood events.

MODELLING FLOOD RUNOFF

The second set of papers presents a variety of methods for estimating flood flows. Some of them are set in the wider context of socio-economic activities. Bardsley & Liu propose a method for rainfall–runoff model construction using manual calibration of hydrograph lag and length, with automated calibration of a large number of “hidden parameters”. They argue that this procedure is amenable to land-use change applications, and hence they test it for catchments in New Zealand and China which have experienced land-use change. Madsen et al. propose a procedure of using water level data and stream flow data to update the model states of a flood forecasting model based on ensemble Kalman filtering. Using a case study in northwestern Italy, they show that the procedure significantly improves the model’s forecast skills as compared to forecasting without updating. Shamseldin & O’Connor combine the river flow forecasts of two individual multiple-input single-output river flow routing models. They use a weighted average method and an auto-regressive model error updating procedure to combine the outputs of these two models into one prediction. However, the performance of the combined model is not significantly better than that of the best of the individual models. Awan analyses the different meteorological causes of floods in Pakistan. He then reviews the suite of modelling approaches used in Pakistan and the more practical aspects of instrumentation and dissemination of the forecasts.

A more local study is provided by Wang et al. who estimate the flood risk for a hydropower project in China. Specifically they calculate the combined hydrological and hydraulic risk of the closure of a diversion channel for different times of the year and find a strong seasonal dependency of this risk. Kuchment et al. derive a flood frequency model combining a stochastic precipitation model and a deterministic rainfall–runoff model. They use the model to examine the effect of changed land-use conditions on the flood frequency characteristics of a catchment in southwestern Russia.

In a much broader context, Booij combines hydrological, hydraulic and economic models to support decision making in flood control and ecosystem upgrading measures. He evaluates scenarios for the Red River basin in Vietnam and China. Some of these scenarios decrease flood damage but they may also decrease total revenues. The paper by Dao & Kaoru deals with a part of the same river basin. However, they adopt a wider view of the socio-economic issues of both flooding and the lack of flooding as a result of a channel constructed to divert the Day River. Their findings, based on a comprehensive questionnaire campaign, suggest that local people

are highly inventive and adapt to the regular occurrence of floods and so are well prepared to cope with regular flooding.

DROUGHT RISK: ANALYSING TRENDS AND PROCESSES

Shimokura & Shibano examine the temporal trends of baseflow recession over a 70-year period in three forest restoration catchments in Japan. They find that flow recessions have become flatter in recent years and interpret this as a result of the development of forest soils associated with the growth of the forest over the years. A somewhat similar study is reported by Sugiyama et al. who compare flow regimes in the upper reaches of streams in the temperate zone (eastern Japan) with those in the tropical monsoon zone (western Thailand). They find vastly different low flow characteristics and give some guidance on the choice of low flow indices to be used for the design of water resources facilities in these contrasting climates.

Chang & Wang investigate precipitation changes in Taiwan during the twentieth century. They find a remarkable consistency between major drought episodes and sulphur rich eruptions of volcanoes around the world. They interpret the causal relationships in terms of the effect of aerosols in the atmosphere on radiative processes. Stancalie et al. analyse the increasing aridization in southern Romania where nine severe droughts have occurred during the past 20 years. They use a coal basin in the area as an example to demonstrate that, to increase ecosystem resistance to long drought effects, stress elements such as anthropogenic activities must be reduced.

The final paper of this section leads on to the reservoir management section of this volume. Kiem & Franks investigate drought risk by analysing the performance of a water storage reservoir in southeast Australia. The find one particular climate index, the Inter-decadal Pacific Oscillation index, to be representative of drought variability. They compare three adaptive management strategies with current practice and conclude that the adaptive strategies based on climate index forecasts can improve drought security.

MANAGEMENT OF RESERVOIR SYSTEMS

Brass & Schumann propose an adaptive model for optimizing a reservoir system which facilitates frequent adjustments of the management strategy. They illustrate the potential of the approach with a hypothetical five reservoir system and analyse possible climate change and demand change scenarios. Arumugam et al. present a framework of water allocation for multiple uses based on annual water contract terms and ensemble forecasts of reservoir inflows using climatic indices. The feasibility of the approach is demonstrated for a reservoir in Brazil. An alternative method that uses control curves is proposed by Adeloye et al. Hypothetical reservoir simulations using the proposed method suggest that, without prior knowledge of inflows, the resulting reservoir performance was acceptable in that recovery was rapid and emptiness was avoided. The authors suggest that control curves provide a much easier and cheaper, yet effective, alternative to operating policies which often require inflow forecasting to be effective.

Cancelliere et al. present a methodology for deriving operating rules for a multi-purpose reservoir system based on optimization and neural network techniques. They

test the method for different hydrological scenarios. In a similar study, Umamahesh develops the operating policy for an irrigation reservoir in India and compares three models of different complexities using simulations. His results suggest that the most complex model performs best. Hanasaki et al. propose a method for deriving reservoir operating rules from globally available data sets and test the method for a river in Thailand. The authors conclude that this method provides more reliable estimates of the seasonal distribution of the global water resources and its inter-annual fluctuation than existing procedures.

WATER RESOURCES MANAGEMENT POLICIES

A comprehensive discussion of the role of dams in integrated water resources management is provided by Petersson & Ostrowski. They suggest that the main challenge of the coming years will be to adapt existing methods of multi-criteria decision-support to water development in general and to dams in particular, and to ensure their practicality and acceptability in a planning context. Murty provides a historical perspective of the national water policies in India, focusing on the amendments to previous policies of the most recent legislation. In a similar vein, Loebis reports on the past and current water management policies in Indonesia. He gives a detailed account of the change of paradigm that is taking place when moving from a centralized water policy to a decentralised participatory water policy, and identifies the role of the stakeholders in the new paradigm.

At a much smaller scale, but in a similar setting, Adi proposes water and soil conservation strategies to reduce soil erosion and to maintain the water quality of a West Java lake. He does this by introducing a ranking of priority development for soil and water conservation, from seasonal crop areas, to forested areas, and perennial crops. He emphasises the need for a water management board to coordinate the diverse water related activities in the catchment area.

WATER RESOURCES MANAGEMENT: METHODS AND CASE STUDIES

Hughes discusses approaches to quantifying environmental flows that appear to still rely heavily on expert judgement in the absence of sufficient hard data concerning biotic responses to changes in river flow regimes. He discusses implementation issues for rivers across South Africa in the context of the water resource management structures and legislation that exist in South Africa. Rabi et al. examine the spatio-temporal variability of rainfall and resulting groundwater recharge in the Jordan River basin including the effects of a recent drought year. They then discuss the implications for water management vis-à-vis the complex hydro-political situation in the area involving Palestine and Israel.

Jimoh & Ayodeji analyse the effects of future interbasin water transfers on the water management of a reservoir in Nigeria. Based on a simulation study they conclude that the water transfer will increase hydropower generation but at the same time increase the flood risk downstream of the dam. To reconcile these competing issues they propose structural flood protection measures. Ikhile & Ikhile examine irrigation activities in a Nigerian catchment and relate them to climate fluctuations. They report that the government has responded promptly to the evidence of decreasing precipitation and has made provisions for accelerated irrigation projects.

Herath et al. present a simulation study in which they examine the effect on the water balance components of infiltration facilities in the suburbs of Tokyo. They conclude that the infiltration facilities both increase the groundwater recharge and reduce the flood flows, effects that are considered favourable in the context of water resource management of this type of urban system. In the context of assessing water resources at much larger scales, Magome et al. propose a suite of methods for monitoring the seasonal variation of water storage in reservoirs. They use satellite images to extract the water surface area, and satellite altimetry to obtain estimates of the lake level, and test the method for a large reservoir in Ghana.

INTEGRATING WATER RESOURCES MANAGEMENT

In this final section, Loáiciga presents a method for calculating sustainable ground-water pumping rates in terms of diverse economic and hydraulic factors. The method maximizes the expected value of the net revenue subject to a number of constraints that ensure consistency with the definition of sustainability chosen. He illustrates the feasibility of the approach by a hypothetical example. Fashchevsky & Fashchevskaya propose an approach for assessing priorities in the use of water resources in a catchment, based on assigning water resources to different uses including drinking water supply, industry, irrigation, recreation, and aquatic ecosystems. Their contrib-ution then focuses on the determination of environmental flows in an integrated management context, illustrated by an example from the Volga River. Kondratyev presents a somewhat similar method, but for an urban setting, for choosing optimum strategies for managing the urban water bodies in St Petersburg. The economic returns for the water users are maximized under the constraints that water quality and the ecological state need to be maintained. Brilly & Globevnik discuss several strategies of integrated and sustainable management of the water resources in a catchment shared by Slovenia and Croatia. They focus on reconciling several conflicting interests including drinking water supply, food production, tourist development and landscape value.

Yang et al. is a fine example of the role of water management in balancing the variability of water resources in both time and space. Northern China is currently experiencing a water shortage as a result of decreasing rainfall trends, despite frequent flooding. Yang et al. discuss a suite of measures including conservation measures and water transfers to balance water shortage and increasing demand. A similar discussion is provided in Sharma for the case of northeastern India where deforestation has resulted in water scarcity because of reduced recharge to aquifers. Sharma suggests that a dramatic shift in management practice is needed, including replacement of the current practice of shifting cultivation by sustainable farming systems.

At a much broader scale, Shiklomanov & Balonishnikova contrast the Conventional and the Sustainable Development scenarios of world water use and water availability. While in the former, world water use would increase by more than a third in the next 20 years, in the latter water use would be almost stable. Whichever scenario will be more appropriate, the authors emphasize the need for multi-facetted solutions to water problems around the world.

_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 11–17.

The impact of climate variability on flood risk

ANTHONY S. KIEM & STEWART W. FRANKSSchool of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australiaa.kiem@studentmail.newcastle.edu.au

Abstract The variability of flood risk across New South Wales, Australia, is analysed with respect to the observed modulation of El Niño/Southern Oscillation (ENSO) impacts. This is achieved through the use of a simple index of regional flood risk. The results indicate that cold ENSO events (La Niña) are the dominant drivers of elevated flood risk. An analysis of multi-decadal modulation of flood risk is achieved using the Inter-decadal Pacific Oscillation (IPO) index. The analysis reveals that IPO modulation of ENSO events leads to multi-decadal epochs of elevated flood risk. However, this modulation appears to affect not only the magnitude of individual ENSO events, but also the frequency of their occurrence. This dual modulation of ENSO processes has the effect of reducing and elevating flood risk on multi-decadal timescales. These results have marked implications for achieving robust flood frequency analyses as well as providing a strong example of the role of natural climate variability. Key words Australia; climate variability; El Niño/Southern Oscillation (ENSO); flood frequency; Inter-decadal Pacific Oscillation (IPO); multi-decadal; Pacific Decadal Oscillation (PDO)

_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 18–25.

Frequency of catastrophic climatic phenomena in Ukraine under the influence of global warming

SVETLANA G. BOYCHENKODepartment of Geography, Kyiv Taras Shevchenko University, 90 Vasylkivska St, Kyiv 03022, Ukrainephenom@mail.univ.kiev.ua

Abstract Data obtained from various historical records and annals (manuscripts) are examined. The statistical analysis of these data shows that the long-term dynamics of frequency or repeatability of the catastrophic climatic phenomena in the territory of Ukraine (in particular, of phenomena determining the regional freshwater resources) depends on the global climatic regime. Global warming or global cooling can influence the repeatability of catastrophic climatic phenomena in the Ukraine. It is found that the repeatability of the events considered is a non-monotonic function of temperature fluctuations. Regression models for the intensity of catastrophic climatic phenomena in Ukraine as a function of an index of climatic anomalies are constructed. These models are used as a scenario for the possible dynamics of repeatability of catastrophic climatic phenomena in the Ukraine as a result of global warming.Key words catastrophic phenomena; droughts; floods; rainy summers; regression models and scenarios; temperature anomalies_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 26–31.

Could global warming have caused the most recent floods on the Tisza River?

ANDRÁS BÁRDOSSYInstitut für Wasserbau, University of Stuttgart, Pfaffenwaldring 61, Stuttgart, D-70550, Germany

bardossy@iws.uni-stuttgart.de

ISTVÁN KONTURDepartment of Water Management, Budapest University of Technology and Economics, Muegyetem rkp.3, Budapest, H-1111 Hungary

JIRI STEHLIKDepartment of Experimental Hydrology, Czech Hydrometeorological Institute, Na Sabatce 17,143 06 Praha 4, Czech Republic

GÁBOR BÁLINTHydrological Institute, Water Resources Research Centre (VITUKI), Kvassay 1, H-1095 Budapest, Hungary

Abstract The Hungarian part of the Tisza River has experienced the highest ever flood peaks during the last four years, higher than any in the 100-year series of observations. The purpose of this paper is to analyse the possible causes of these floods and establish methodologies for the assessment of design floods. The first task is to identify the common meteorological features occurring prior to floods. Large-scale atmospheric circulation patterns are considered for this purpose. The time series of these variables shows non-stationary behaviour. The time series of circulation patterns is investigated for the frequencies of the patterns and their duration. The relationship between the circulation patterns and discharge changes helps identification of the amount to which climate change or climate fluctuations are responsible for the unusual behaviour of the Tisza River.Key words climate change; circulation pattern; flood; Tisza River, Hungary_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 32–39.

Extreme precipitation and floods in the changing world

ZBIGNIEW W. KUNDZEWICZResearch Centre for Agricultural and Forest Environment, Polish Academy of Sciences, Bukowska 19, 60-809 Poznań, Poland, and Potsdam Institute for Climate Impact Research, Telegrafenberg, 14 412 Potsdam, Polandzkundze@man.poznan.pl; zbyszek@pik-potsdam.de

Abstract In recent decades, flood losses have shown a rapid growth tendency worldwide, which can be linked to socio-economic, hydrological and climatic factors. An increase in the flood risk is also foreseen for the future. Several land-use changes, such as deforestation and urbanization, reduce the available water storage capacity and exacerbate the flood hazard. Demographic pressure causes encroachment of informal settlements into hazardous locations in flood plains, e.g. around mega-cities in developing countries. Over-reliance on the safety provided by flood control works enhances accumulation of wealth in endangered areas. Climate impacts contribute considerably to the increase of flood exposure. As the atmosphere’s water holding capacity grows with temperature, the possibility of intensive precipitation also increases. Higher and more intense precipitation has been observed already in many areas of the globe and this trend is expected to be even more pronounced in the future, warmer world. In a number of studies, floods have been found to become more frequent and intense. Yet, it would be a gross oversimplification to state that floods have uniformly exhibited growing trends everywhere. Adverse effects on floods have already been observed due to changing climatic variability (e.g. related to ENSO), and they are also projected to amplify. Despite the considerable investments into flood protection, in many countries there is a rising vulnerability to floods, as the increase of exposure to floods is faster than the growth of the adaptive capacity.Key words climate change; climate impacts; climate variability; floods; global change; hydrological extremes; precipitation_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 40–48.

Testing trends in annual maximum discharge series in Israel

ARIE BEN-ZVIIsrael Hydrological Service, PO Box 36118, Jerusalem 91360, Israel, and Negev Academic College of Engineering, 71 Basel Street, Beer Sheva 84100, Israelarieb20@water.gov.il

BENJAMIN AZMONIsrael Hydrological Service, PO Box 33140, Haifa, Israel

Abstract A variety of statistical tests were carried out on 64 annual maximum discharge series observed in Israel during the last six decades. The period of observation at each of the stations selected is at least 25 years, with an average of 42 years per station. The tests aimed at detecting trends in the central values of the discharges, as well as in their variation. Except for one region, the detected changes are of local extent, if any. A decline in the annual maximum discharges and in their variability is found for the Upper Jordan River and its tributaries. A general rise in the variability is found over most other regions. These appear to result from changes in the meteorological causes of high discharges. Few high discharges occurred in the 1970s and in the early 1980s, whilst many occurred in the 1990s. Key words annual maximum discharges; arid areas; Israel; regional analysis; semiarid areas; statistical tests; trend_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p 49–58.

Regional flood risk—what are the driving processes?

RALF MERZ & GÜNTER BLÖSCHLInstitut für Hydraulik, Gewässerkunde und Wasserwirtschaft, Technische Universität Wien, Karlsplatz 13/223, A-1040 Wien, Austria merz@hydro.tuwien.ac.at

Abstract In this paper a framework for identifying types of causative mechanisms of floods is proposed. The types are long-rain floods, short-rain floods, flash floods, rain-on-snow floods and snowmelt floods. A catchment perspective is adopted, i.e. the focus is on the catchment state and the atmospheric inputs rather than on atmospheric circulation patterns. A number of process indicators, including the timing of the floods, storm duration, rainfall depth, snowmelt, catchment state, runoff response dynamics and spatial coherence, are presented. Based on a combination of these indicators and diagnostic regional plots, the process types of 11 518 maximum annual flood peaks in 490 Austrian catchments are identified. Of the flood peaks, 43% are long-rain floods, and only 3% are snowmelt floods, and the relative contrib-ution of the types changes with the flood magnitude. All process types exhibit pronounced seasonal patterns. The flood types analysis provides useful information for flood frequency regionalisation. Key words Austria; flood processes; flood process typology _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 59–64.

Comparison of maximum precipitation estimates with runoff depths for the 1342 and 2002 Central European flood events

GERD TETZLAFF, MICHAEL BÖRNGEN, MANFRED MUDELSEE & ARMIN RAABEUniversität Leipzig, Institut für Meteorologie, Stephanstr. 3, D-04103 Leipzig, Germanytetzlaff@uni-leipzig.de

Abstract Using a conceptual precipitation model, probable maximum point precipitation for Central Europe was estimated as 800 mm in 24 hours. Precipitation depths back-calculated from flood marks of the July 1342 flood on the River Main are about 500 mm in 24 hours.

The catchment precipitation depths of the August 2002 Elbe flood were about 140 mm.Key words Central Europe; flood events; maximum precipitation; meteorology_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 67–74.

An approach to creating lumped-parameter rainfall–runoff models for drainage basins experiencing environmental change

EARL BARDSLEYDepartment of Earth Sciences, University of Waikato, Private Bag 3105, Hamilton, New Zealande.bardsley@waikato.ac.nz

SUXIA LIUInstitute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Datun Road, Building 917, An Wai, Beijing 100101, China

Abstract Many drainage basins experience hydrological change due to land- use modification and the consequential recalibration of conceptual rainfall–runoff models may be cumbersome. We describe a model-constructing approach which leads to straightforward calibration/recalibration using a hybrid of manual and automated methods. Hydrographs are simulated using weighted finite-mixture distributions where the “distributions” are just lists of hydrograph-like constants for general application. This creates many-parameter models which enable the use of standard, stable, least-squares algorithms subject to a non-negativity constraint. An illustrative model application is given for drainage basins in New Zealand and China which have experienced land-use change. The example model employs manual calibration of hydrograph lag and length, with automated calibration of 85 hidden parameters. In addition to land-use change applications, the straightforward nature of the automated calibration process should make models of this type amenable to the auto-updating requirements of flood forecasting models.Key words China; estimation; model; New Zealand; parameter; runoff _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 75–81.

Data assimilation in the MIKE 11 Flood Forecasting system using Kalman filtering

HENRIK MADSENDHI Water & Environment, Agern Allé 11, DK-2970 Hørsholm, Denmarkhem@dhi.dk

DAN ROSBJERG, JESPER DAMGÅRD & FRANDS SØBJERG HANSENEnvironment & Resources DTU, Technical University of Denmark, Building 115, DK-2800 Kongens Lyngby, Denmark

Abstract A procedure is presented for assimilation of water levels and fluxes in the MIKE 11 Flood Forecasting (FF) system. The procedure implemented is based on the ensemble Kalman filter that provides a cost-effective and efficient updating and uncertainty propagation scheme for real-time applications. Up to the time of forecast, the model is updated according to the Kalman filter algorithm using the available measurements. In forecast mode, the Kalman filter provides an ensemble forecast that is used for estimation of water levels and fluxes in the river system and the associated uncertainties. A test example is presented where the MIKE 11 FF system is applied for flood forecasting in the Piedmont region in the northwestern part of Italy. Application of the ensemble Kalman filter significantly improves the forecast skills as compared to forecasting without data assimilation.Key words data assimilation; ensemble Kalman filter; flood forecasting; Kalman filter; updating_________________________________________________________-

Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 82–89.

A “consensus” real-time river flow forecasting model for the Blue Nile River

ASAAD Y. SHAMSELDINDepartment of Civil Engineering, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UKa.shamseldin@bham.ac.uk

KIERAN M. O’CONNORDepartment of Engineering Hydrology, National University of Ireland, Galway, Ireland

Abstract The efficacy of using a consensus real-time river flow-forecasting model for the Blue Nile River is investigated. The selected consensus model combines the river flow forecasts of two individual multiple-input single-output river flow routing models, both operating in simulation non-updating mode, the first being a non-parametric linear storage model and the second having the parametric structure of a multi-layer feed-forward neural network. The upstream inflow to the Blue Nile and the outflows of its two major tributaries are used as inputs to both models in order to provide the simulation-mode river flow forecasts just upstream of Khartoum, the capital city of Sudan. The weighted average method (WAM) is used to combine the simulation-mode forecasts of these two models. The consensus real-time river flow forecasts are obtained by updating the combined simulation-mode forecasts using an auto-regressive (AR) model error updating procedure. Disappointingly, the results show that the performance of the consensus model, operating in the simulation mode, is not different from that of the best individual model, i.e. that the linear model is given practically zero weight in the consensus model. However, significant improvements in the forecasting performance are obtained after updating the simulation-mode consensus forecasts.Key words Blue Nile; consensus real-time forecasting; linear model; neural network_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 90–98.

Flood forecasting and management in Pakistan

SHAUKAT ALI AWAN Flood Forecasting Division, 46 Jail Road, Lahore 54000, Pakistannffb@paknet4.ptc.pk

Abstract Meteorologically, there are two situations which may cause three types of floods in Pakistan: (i) meteorological situation for Category-I floods, the seasonal low is a semi-permanent weather system situated over south-eastern Baluchistan, southwestern Punjab, adjoining parts of Sindh, which intensifies and causes moisture from the Arabian Sea to be brought up to the upper catchments of the Chenab and Jhelum rivers; (ii) the situation for the more severe Category-II and Category-III floods, is linked with the monsoon low/depression. Such monsoon systems originate in the Bay of Bengal region and then move across India in a general west/northwesterly direction to arrive over Rajasthan or the adjoining states of India. Flood management in Pakistan is a multi-functional process involving a number of different organizations. The first step in the process is issuance of a flood forecast/warning which is prepared by the Pakistan Meteorological Department (PMD) utilizing satellite cloud pictures and quantitative precipitation measurements using radar data, in addition to the conventional weather forecasting facilities. For quantitative flood forecasting, hydrological data is obtained through the Provincial Irrigation Department and WAPDA. Furthermore, improved rainfall–runoff and flood routing models have been developed to provide more reliable and explicit flood information to a flood prone population.Key words Category I, II and III floods; monsoon low/depression; Pakistan_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at

Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 99–106.

Risk assessment for closure of the diversion channel at the Three Gorges Project on the Yangtze River

CAIJUN WANG, SHENGLIAN GUO, XIANGRONG TIANNational Key Laboratory of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 430072, China wangcaijun@sina.com

YONGHUA ZHU College of Mathematics and Statistics, Wuhan University, Wuhan 430072, China

Abstract This paper is mainly focused on the assessment of both the hydrological and hydraulic risks in the closure of the diversion channel Three Gorges Project (TGP) at the Yangtze River, which was carried out at the end of 2002. By using the daily flow data of the Yichang hydrological station during the period of 1877–2000, techniques such as the Pearson type-3 distribution, the flow duration curve and a Poisson process model were used to estimate design flow discharge and assess the hydrological risks. In a second step, a one dimensional unsteady flow hydraulic model was used to obtain the values of total energy head, flow velocity, etc., for the given design flow. Assuming the total energy head of the closure gaps as a random variable with normal distribution, a model was proposed for calculating the hydraulic risk of the closure of the TGP diversion channel. Key words China; diversion channel closure; risk assessment; Three Gorges Project

_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 107–114.

Application of dynamic-stochastic runoff generation models for estimating extreme flood frequency distributions

L. S. KUCHMENT, A. N. GELFAN & V. N. DEMIDOVWater Problems Institute of the Russian Academy of Sciences, 3 Gubkina Str., 119991 Moscow, Russia kuchment@mail.ru

Abstract A physically based model of runoff generation is coupled with Monte Carlo simulations of the model inputs to estimate flood peak frequency distributions. The runoff generation model represents the following hydrological processes: snow cover formation and snowmelt, freezing and thawing of soil, vertical soil moisture transfer and evaporation, overland and channel flow. The Monte Carlo simulations of snowmelt runoff are based on stochastic models of daily precipitation series, daily air temperature and daily air humidity deficit (for continuous simulations during autumn–winter–spring seasons) or statistical distributions of snow water equivalent, depth of frozen soil, and soil moisture content before snowmelt (for simulations only during snowmelt flood events). To simulate the rainfall runoff during a warm period, the statistical distributions of precipitation volumes, precipitation duration, duration of dry periods, and mean air humidity deficit for dry periods, were used. A case study was carried out for the Seim River basin situated in the southwestern part of Russia. The dynamic-stochastic models developed were applied for estimating changes in the exceedence probabilities of runoff characteristics for three land-use scenarios. Uncertainties in estimating flood characteristics caused by errors in model parameters have been investigated.Key words Monte Carlo simulation; physically based modelling; rainfall flood; Seim River, southwest Russia; snowmelt flood; stochastic modelling_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 115–122.

Decision support system for flood control and ecosystem upgrading in the Red River basin

M. J. BOOIJDepartment of Civil Engineering, University of Twente, PO Box 217, 7500 AE Enschede,The Netherlandsm.j.booij@ctw.utwente.nl

Abstract A decision support system (DSS) for the selection of a suitable combination of flood control and ecosystem upgrading measures was developed. This was achieved by carefully selecting the most appropriate model environment for the DSS. The hydrological, hydraulic and socio-economic models within the DSS are constructed in a consistent way, taking into account the project objectives, characteristics of the measures, spatial and temporal scales and future scenarios. The developed DSS was applied to the Red River basin in Vietnam and China to evaluate a number of measures. This reveals that some measures may decrease the flood damage, but may also result in a decrease in total income and hence total revenues. The described results are an illustration of how measures can be selected in the DSS. More data collection and model calibration and validation are needed before employing the DSS for real flood management.Key words appropriateness; DSS; ecosystems; flooding; HBV model; Red River; scales_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 123–129.

Flood control—environmental and socio-economic issues: case study of a diversion area in Vietnam

PHAN THI ANH DAO & TAKARA KAORUDisaster Prevention Research Institute, Kyoto University, Uji, Kyoto 611-0011, Japandaopat@yahoo.com, takara@rdp.dpri.kyoto-u.ac.jp

Abstract Flood control is an important issue in Vietnam and appropriate policies, strategy and action to control floods and mitigate its damage, and to help people to recover after floods, has always been the government’s great concern. The Day River basin is a flood diversion region, which is an important region in practicing flood protection in Vietnam. Understanding environmental and socio-economic problems caused by floods in the inundation area of the Day River basin is the focus of this paper. Analysis of flood impacts and adaptations made by local people in flood-endangered areas is another major part of the paper. Findings presented here could be helpful for determining appropriate flood control plans. Key words adaptation; environment; flood control; impacts; socio-economic development _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 133–140.

Effects of forest restoration in mountainous basins on the long-term change in baseflow recession constants

JUNJI SHIMOKURA & HIROFUMI SHIBANOGraduate school of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japanc-mo@uf.a.u-tokyo.ac.jp

Abstract Existing daily discharge and precipitation data on three basins that underwent forest restoration over a 70-year period was used to explore changes in the baseflow recession constants and the storage capacities of the basins. The basins are located in a mountainous region of weathered granite covered with rapidly growing secondary forest, in Japan.

Continuous daily baseflow data of non-precipitation periods of more than seven days were extracted from the 70-year data and applied to an equation that expresses runoff from an unconfined aquifer. Over the 70 years, a decreasing tendency in the recession constant existed in most cases. It was concluded that development of the forest soil layer caused the downward trend in spite of some upward effects due to evapotranspiration. The storage capacity increases in the basins were estimated using the change of recession constant and the standard value of low flow (discharge of the 275th day on the flow duration curve).Key words baseflow recession; evapotranspiration; forest recovery; soil layer development_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 141–147.

Impact of climate on flow regimes of the upper reaches of streams

HIRONOBU SUGIYAMAGraduate School of Science and Technology, Niigata University, Niigata 950-2181, Japanhydsugi@cc.niigata-u.ac.jp

VARAWOOT VUDHIVANICHFaculty of Engineering, Kasetsart University, Kamphaengsaen Campus, Nakhon Pathom 73140, Thailand

ANDREW C. WHITAKERGraduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan

KOSIT LORSIRIRATRoyal Irrigation Department, Dusit Bangkok 10300, Thailand

Abstract Comparison of flow regimes in the upper reaches of streams in the temperate zone (eastern Japan) and the tropical monsoon zone (western Thailand), and evaluation of an index of low flow are carried out aiming towards the synthesis of water resources evaluation. The flow regimes of the upper reaches of streams are stochastically evaluated by applying the stochastic flow duration (SFD) curve. On the basis of a comparison of values read from the SFD curve with the 10-year probability value, it is shown that the discharge exceeded 97% of time in the tropical monsoon zone is only about one-fifteenth that of the temperate zone. This difference indicates that this flow regime is uncomfortable for planning if a water resources planner evaluates a flow with the 10-year probability in the tropical zone. It may be argued that a more severe probability of occurrence (i.e. longer than 10 years) should be adopted for the design of water resources facilities in the tropical monsoon zone. By comparing the recession shape of the lower part of the flow duration curve, it is seen that the persistency of low flow in the temperate zone is stronger than that in the tropical monsoon zone. The index of low flow is also discussed by examining the relation between the index used in Japan and that in the United States of America. The relationship between the 10-year probability for annual minimum flow averaged over a consecutive period of seven days (Q10,7) of a given year and the 10-year probability value for the discharge exceeded 97% of the time (Q97 10) is strong. This implies that the Q9710 index used in Japan can be recognized as an index of low flow.Key words basin hydrology; flow regime; low flow index; non-exceedence probability; stochastic flow duration curve; temperate zone; tropical zone; water resources_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 148–157.

Did sulfur-rich volcanic eruptions affect drought episodes in Taiwan?

FONG-CHIAU CHANGDepartment of Atmospheric Sciences, National Taiwan University, Taipei, Taiwanfchang@linho2.as.ntu.edu.tw

CHUNG-HO WANG Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan

Abstract Precipitation change in Taiwan during the twentieth century is investigated. Six major drought episodes in Taiwan during the period from 1897 to 2001 are identified. They are 1899–1902, 1906–1910, 1913–1916, 1960–1965, 1978–1980 and 1993–1997. That there is one episodic high sulfur-rich volcanic eruption which corresponds to each drought event is intriguing. Sulfur-rich volcanic eruption forcing from the Pinatubo eruption in 1991 is evident in the drought episode of 1993–1997. The Agung eruption (1963) coincides with the centre of a drought episode (1960–1965) of about a half decade duration. Together with all the other eruptions, this indicates that high sulfur-rich volcanic eruptions bear some relationships to drought episodes in Taiwan with durations of from three years to six years. Key words drought episodes; precipitation change; sulfur-rich volcanic eruptions; Taiwan _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 158–164.

Assessment of the impact of climate and ecosystem changes on drought conditions: case study from Romania

GHEORGHE STANCALIE, SIMONA CATANA, ION POIANA, ANISOARA IORDACHE & VASILE CRACIUNESCURemote Sensing and GIS Lab, National Institute of Meteorology and Hydrology, Soseaua Bucuresti –Ploiesti, no.97, sector 1, 71552 Bucharest, Romaniagheorghe.stancalie@meteo.inmh.ro

Abstract In the last two decades, increasing aridization has occurred under the drought conditions that have affected certain regions in southern Romania. The study area corresponds to the Oltenia region, where nine very severe drought years were recorded during the last 20 years. The Motru-Rovinari coal basin is located in this region and was chosen as an example to demonstrate the modifications due to human intervention which have affected the land surface. Updated representations of the topography, as well as of the land cover and land use have been obtained from analysis of remotely sensed data and cartographic documents. Analysing the meteorological and hydrological factors, a natural aridization tendency, associated with the climate variability at the regional scale, has been observed. The main conclusion is that in order to increase ecosystems’ resistance to long drought effects, stress elements such as anthropogenic activity must be decreased.Key words anthropogenic impact; climate changes; drought; GIS; remote sensing; Romania_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 165–172.

Elevated drought risk due to multi-decadal climate variability

ANTHONY S. KIEM & STEWART W. FRANKSSchool of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australiaa.kiem@studentmail.newcastle.edu.au

Abstract This study investigates multi-decadal variability of drought risk by analysing the performance of a water storage reservoir in New South Wales, Australia, during different climate epochs defined using the Inter-decadal Pacific Oscillation (IPO) index. The performance of the reservoir is also analysed under three adaptive management techniques and these are compared with the current “reactive” management practices. The results indicate that IPO modulation of both the magnitude and frequency of El Niño/Southern Oscillation (ENSO) events has the effect of reducing and elevating drought risk on multi-decadal timescales. The results also confirm that adaptive reservoir management techniques,

based on ENSO forecasts, can improve drought security and become significantly more important during dry climate epochs. These results have marked implications for improving drought security for water storage reservoirs. A possible explanation for the extreme drought in Australia during 2002/2003 is also suggested.Key words Australia; climate variability; drought; El Niño/Southern Oscillation (ENSO); hydrological impacts of ENSO; Inter-decadal Pacific Oscillation (IPO); La Niña; Pacific Decadal Oscillation (PDO); water resource management_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 175–183.

An optimization model for reservoir systems to assist in coping with changes in demand and supply conditions

CARSTEN BRASS & ANDREAS H. SCHUMANNInstitute of Hydrology, Water Management and Environmental Engineering, Ruhr-University Bochum, Universitätsstraße 150, D-44780 Bochum, Germanycarsten.brass@ruhr-uni-bochum.de

Abstract Changes in the basic conditions of reservoir management regularly require adjustments of the management policy. For this process, a flexible Stochastic Dynamic Programming (SDP) optimization-model was developed. The model includes options to change the system configuration by adding or removing reservoirs and modifying optimization objectives, release targets and reservoir characteristics (e.g. temporary reduction of storage capacity). The applicability of this model is presented in a case study with five reservoirs, where the effect of runoff changes (implied by possible climate change scenarios) and demand changes on the performance of the reservoir operation are estimated.Key words adjustability; optimization by SDP; reservoir systems _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 184–191.

Water allocation for multiple uses based on probabilistic reservoir inflow forecasts

SANKAR ARUMUGAM1, ASHISH SHARMA2 & UPMANU LALL1

1 International Research Institute for Climate Prediction, Palisades, New York 10964, USA

sankar@iri.columbia.edu2 School of Civil and Environmental Engineering, The University of New South Wales, Sydney, Australia

Abstract Allocating water to downstream users is traditionally a conservative exercise. The amount of water to be allocated for each use is usually decided based on stringent assumptions about the sequence of likely reservoir inflows and a requirement that the reliability of the allocated amount also has to be specified. But, the inflows that actually occur are often predictable based on catchment storage and longer scale climatic fluctuations. This paper presents a framework towards water allocation for multiple uses by developing: (a) 18 months-ahead ensemble forecasts of reservoir inflows based on larger scale climatic indices; (b) the specification of the annual water contract terms; (c) a water allocation model that maximizes the release given the reliability and the contract terms. The approach is demonstrated through an application to the Oros Reservoir in the state of Ceara, Brazil by maximizing annual reservoir yields using ensemble forecasts of inflows conditioned on the climate information developed for the period 1913–1995. Results from this study show the usefulness of this water allocation framework to issue annual water contracts using reservoir inflow forecasts and develop adequate strategies towards better water system management in regions where the link to low-frequency climate variability is strong. Key words Brazil; climate variability; probabilistic forecasting; water allocation_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 192–199.

Improved heuristic reservoir operation using control curves incorporating the vulnerability norm

ADEBAYO ADELOYE School of the Built Environment, Heriot-Watt University, Edinburgh EH14 4AS, UKa.j.adeloye@hw.ac.uk

ATHANASIOS PSAROGIANNISKiprou 70, Lamia, TK 35100, Greece

MAJID MONTASERIDepartment of Irrigation Engineering, Urmia University, PO Box 498, Urmia, Iran

Abstract Decisions about water releases from dam reservoirs are often guided by rule curves which show target storage levels that should be maintained in the reservoirs in different months of the year. If these targets are unattainable in any month during operation, then a cutback in releases has to be made in that month. However, because of the way they are developed, traditional control curves do not give any guidance on the level of the cutback, implying that the action of the operator may or may not succeed. In this paper, a sequential reservoir analysis technique was used to develop control curves with an integral attribute of vulnerability, which defines the level of cutback. The superiority of the new control curves over traditional ones was demonstrated by using them to simulate some hypothetical reservoirs. Key words control curves; England; Iran; modified SPA; reservoir planning; reservoir simulation_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 200–207.

Optimal short-term operation of a multipurpose reservoir system under limited water supply

ANTONIO CANCELLIERE, GIUSEPPE GIULIANO, VINCENZO NICOLOSI & GIUSEPPE ROSSI Department of Civil and Environmental Engineering, University of Catania, V. le A. Doria 6, I-95125 Catania, Italyggiuliano@dica.unict.it

Abstract A methodology is presented for deriving operating rules for a multipurpose reservoir system through the application of optimization and neural networks techniques. In order to find operating rules able to cope with different degrees of drought severity, several scenarios of water resources availability have been hypothesized. The -constraints multi-objective optimization method was used to find nondominated solutions that represent the best trade-off between two competing objectives, namely the sums of squared irrigation deficits and the municipal volumetric reliability. Then neural networks were trained by means of adaptive techniques with the purpose of modelling the results of the optimization model. In particular, future releases were expressed as a function of the current reservoirs’ storage volumes. Effectiveness of the selected operating rules was assessed through simulation of the system’s operation for dry, normal and wet scenarios, on the basis of several operational performance indices. Results showed that operating rules obtained through neural networks can perform well under different hydrological scenarios and therefore can be effectively used for optimal short-term operation.Key words multiobjective optimization; neural networks; operating rules; reservoir operation _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 208–214.

Evaluation of alternate objective functions for optimal operation of an irrigation reservoir under a multi-crop environment

N. V. UMAMAHESHWater & Environment Division, Department of Civil Engineering, National Institute of Technology, Warangal 506 004, Andhra Pradesh, Indiamahesh@nitw.ernet.in; mahesh_n@nettlinx.com

Abstract In the present study, three Stochastic Dynamic Programming (SDP) models with different objective functions were used to develop the operating policy for an irrigation reservoir, namely, Sri Rama Sagar Reservoir on the River Godavari in Andhra Pradesh, India. The reservoir is a major project, meeting the irrigation requirements over a large command area. The three SDP models model the objectives of the reservoir with different levels of mathematical complexity. The performance of the reservoir under these three operating policies is compared through simulation. Three criteria, namely reliability, resilience and average annual deficit of water supply are used to evaluate the performance of the reservoir under the alternative operating policies developed.Key words irrigation reservoir; multiple crops; operation policy; River Godavari, India; simulation; stochastic dynamic programming; water allocation _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 215–223.

Simulating the discharge of the Chao Phraya River taking into account reservoir operation

NAOTA HANASAKI, SHINJIRO KANAE, KATUMI MUSIAKEInstitute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japanhanasaki@iis.u-tokyo.ac.jp

TAIKAN OKIResearch Institute for Humanity and Nature, 335 Takashimacho, Kyoto 602-0878, Japan

Abstract A simple reservoir operation model for Total Runoff Integrating Pathways (TRIP), which is one of the global river routing network models, is introduced. To overcome the shortage of reservoir operating rule information, the model is designed to set an operating rule for each reservoir using globally available data sets and few parameters. The model is applied to the Chao Phraya River in Thailand to validate its performance. The correspondence between the model results and observations is judged to be good enough for applying the model in global and continental studies.Key words Chao Phraya River(Thailand); global river discharge simulation; reservoir operation model; TRIP _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 227–232.

Large dams—a contribution to sustainable water and energy development?

ELKE PETERSSONDarmstadt University of Technology, Centre for Interdisciplinary Studies of Technology, Hochschulstraße 1, D-64289 Darmstadt, Germanypetersson@zit.tu-darmstadt.de

MANFRED W. OSTROWSKIDarmstadt University of Technology, Institute for Hydraulics and Water Resources Engineering, Section for

Hydrology and Water Management, Petersenstraße 13, D-64287 Darmstadt, Germany

Abstract Looking back on 5000 years of history, dams are still a decisive technology to balance the uneven distribution of water in space and time, raise the water head for hydropower generation, and reduce or increase downstream runoff, thus delivering flood protection or low flow augmentation. Because strong negative impacts on both humans and nature were experienced through large dams, especially during the second half of the twentieth century, new projects were hampered during the 1980s and 1990s. Both governance and economy systems play a decisive role in these developments. The World Commission on Dams was founded in 1998 to carry out a global review on the effectiveness of dams, and to develop criteria and guidelines to make new dam building projects more sustainable. For future planning, special attention has to be given to a participatory approach as well as to the impacts of global change and uncertainty aspects. To cope with these requirements it is suggested that multi-criteria decision support should be implemented as a planning method. Key words evaluation approach; global change; impacts of dams; impacts on dams; large dams; multi-criteria decision support; World Commission on Dams_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 233–239.

India’s national water policy and water management

K. S. MURTY101 Sneh Chaya Apartments, 28 Hindustan Colony, Amravati Road, Nagpur 440 033, Indiaankush99_99@yahoo.com

Abstract The average annual precipitation over India’s landmass is 4000 km3 while the annual water resource of the country has been estimated by the National Commission as 1953 km3, including the groundwater component of 432 km3. However, the usable water resource is less than 1086 km3, of which about 600 km3 are actually used. By the year 2050 the increase in population, urbanization and demands from various other sectors will need between 973 km3

and 1180 km3 of water depending on the projections. A National Water Policy was adopted in 1987 by the Government, drawing attention to the need for increased efficiency in the use of water through education and other measures. Priority was, however, accorded to drinking water. Realizing the inadequacies in the 1987 Policy, the Central Government revised it and announced a New National Water Policy in April 2002 that recognizes the importance of water as part of the ecological system, for drainage basin development, rainwater harvesting, and drainage systems as an integral part of the project planning, all as integral components of India’s water management.Key words India; national perspective; national water policy; water management_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 240–247.

Towards a new paradigm for integrated water resources management and development in Indonesia

JOESRON LOEBIS Research Institute for Water Resources, Jl. Ir. H. Juanda 193, Bandung 40135, Indonesiajoesron@melsa.net.id

Abstract Indonesia is currently decentralizing water resources management to regional governments. In order to achieve the objectives of an efficient and effective water supply to all stakeholders, the implementation of a policy of “one river basin, one plan and one integrated water resources management and development” is urgently needed. This policy focuses on establishing a proper institutional framework, exploring self-financing system management strategies, as well as legal aspects and water rights for development and management. In this paper, establishing an institutional framework is the main issue, which is very complex because of the interacting domains of economy, society, law, culture, science

and technology. An interdisciplinary analysis of all the above factors are thus very important. The paper also addresses the modification of existing aspects of water resources related to the present law and regulations, establishing a networking of hydrological data collection, providing decision support systems, analyses of the conjunctive use of surface water and groundwater at the local scale, water quality control and role sharing between central and regional governments.Key words Indonesia; institutional framework; water resources management_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 248–258.

Proposed soil and water conservation strategies for Lake Rawa Dano, West Java, Indonesia

SENO ADIAgency for the Assessment and Application of Technology (BPP Teknologi), BPPT Building 2, lt. 18, jl Thamrin No. 8, Jakarta 10340, Indonesiaseno1234@yahoo.com

Abstract Lake Rawa Dano lies within a volcanic caldera in a reserve area of West Java. Locally, Rawa Dano means “swampy lake”, reflecting that the lake is mostly covered by the swamp forest and water plantations. The lake acts as a water supply for the Krakatao Industrial Estate as well as for the city of Cilegon. There is significant soil erosion in the lake catchment with sediment production averaging 3.32 t ha-1 year-1. In addition, lake siltation and water plant blooming has caused a decline of lake water quality. Soil and water conservation strategies are needed urgently to mitigate the sediment and nutrient inputs to the lake. The first step is to adopt a civil engineering approach by constructing control dams, check dams, and gully plug/drops, especially for slopes of >30% where there is a high erosion risk. Subsequently, systems of minimum tillage farming, agroforestry, or farm forestry need to be established. The establishment of a water authority is important to aid reversion to a more natural hydrological status by controlling forest encroachment, encouraging soil and water conservation practice, and regulating community development. The water authority could gain income from local water beneficiaries then re-invest in further soil and water conservation practices.Key words conservation; erosion hazard; Indonesia; institution; strategies_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 261–268.

Environmental flow requirements in water resource planning and operation

DENIS HUGHES Institute for Water Research, Rhodes University, Grahamstown, South Africadenis@iwr.ru.ac.za

Abstract There have been recent developments in the methods that are available for determining the environmental flow requirements of rivers in South Africa (referred to as the ecological reserve). There is now a range of approaches available that are based on the “building block methodology” but are designed to provide results with different levels of confidence. These methods have been developed and improved over the last few years with due regard for the implementation of the reserve in water resource planning and operational management. However, it is now clear that there are other problems, which were not immediately apparent in the past, that must be addressed before practical implementation is possible throughout the country. This paper briefly reviews some of the models that have been developed to contribute to implementation and highlighting the problems that have yet to be solved.Key words ecohydrology; environmental flows; water resource management

_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 269–276.

Integrated water resources management under complex hydro-political conditions: the Palestinian case study

AYMAN RABI, ABDELLATIF KHALED & NATASHA CARMIPalestinian Hydrology Group, PO Box 25220, Jerusalem 97300phgrabi@yahoo.com; phg@palnet.com

Abstract Integrated water resources management in the Jordan River basin is hindered by the complex hydro-political situation characterized by natural water scarcity, the shared nature of water resources, conflicting demands, and intensive development and use of resources. In addition, the lack of final regional water agreements defining the exact shares, roles and responsibilities of each riparian, especially the Palestinians, coupled with the lack of adequate water laws, regulations and plans governing water in Palestine, make it difficult to manage these resources efficiently, especially under the given uncertainties. The foremost significant uncertainty is that related to climate change in general and to drought in particular. Changes in climate over the years have assisted in aggravating problems in water quantity and quality. Given that the region is characterized by high variability in rainfall depth over time and space, the occurrence of a drought event is highly random. In 1998/99, the winter rainfall was the lowest of the past 100-year long history of rainfall records. This drought has led to water quality deterioration, a drop in groundwater levels and decline in spring discharge. Accordingly, water shortage has become very acute and available supply falls short of meeting demand. Under the foreseeable future scenarios of population growth and development needs, this water shortage is expected to intensify. The average population growth rate is estimated at 4%, which means that the population is expected to double in the coming two decades. Key words climate change; drought; integrated water management; resource sustainability; uncertainty; water quantity and quality _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 277–286.

Impact of the Gurara River (Nigeria) interbasin water transfer scheme on the Kaduna River at the Shiroro Dam

O. D. JIMOH & O. S. AYODEJICivil Engineering Department, Federal University of Technology, Minna, Nigeriaodjimoh@wwlkad.com; odjimoh@skannet.com

Abstract The Kaduna River is impounded at Shiroro for the sole purpose of generating electricity. There is, however, a persistently low reservoir level between November and June due to seasonal fluctuations in the river inflows to the Shiroro Reservoir. A proposed scheme to increase Shiroro Reservoir storage is to transfer 1500 Mm3 of water (which is about 10% of the mean annual inflow to Shiroro Reservoir) from the Gurara River to the Shiroro Reservoir between December and May. The interbasin water transfer is intended to stabilize the Shiroro Reservoir level. This paper examines the effect of the water transfer on the storage level of this reservoir. Fourteen years of daily inflow record were used to study the real-time operation of the reservoir. The results indicate that with the water transfer, the reservoir attains its maximum operating level in July and maintains it until September or October, whereas the maximum operating level would have been attained in August without the transfer. Although the interbasin water transfer into the Shiroro Reservoir would enhance power generation, there would be an increase in the frequency and severity of annual flooding downstream of the dam. Appropriate flood damage mitigation measures are recommended for the Kaduna River basin to optimize the benefit of the proposed interbasin water transfer scheme.Key words impact assessment; interbasin transfer; reservoir operation_________________________________________________________-

Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 287–293.

Effects of climate change on irrigation activities: a case study of the Benin-Owena River basin irrigation projects

CATHERINE I. IKHILEDepartment of Geography and Regional Planning, University of Benin, PMB 1154,Benin City, Nigeriaikhilek@yahoo.com

GEORGE U. IKHILEc/o Scripture Union (Nigeria), PO Box 743, Benin City, Nigeria

Abstract The effects of climate change on irrigation activities in the Benin-Owena River Basin (BORB), southwestern Nigeria, were investigated, using rainfall and temperature data from 1961 to 2000 with irrigation activity data from 1990 to 2000. Climate records showed a large variation in annual rainfall between 1961–1980. The rainfall variation between 1980–2000 was less pronounced, and rainfall was much lower. The period 1982–1986 exhibited the greatest downward trend in rainfall. The decadal range of temperature showed a gradual warming of the environment. Increasing temperatures and decreasing rainfall, coupled with an increasing population, led farmers and policy makers in Nigeria to embark on massive irrigation activities from the 1990s to 2000. Farm productivity levels and irrigations activities in Edo State are discussed.Key words Benin-Owena River basin; climate change; irrigation; Nigeria; rainfall; temperature_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 294–302.

A simulation study of infiltration facility impact on the water cycle of an urban catchment

SRIKANTHA HERATHEnvironment and Sustainable Development Programme, United Nations University, 5-53-70 Jingumae, Shibuya-ku, Tokyo 150-8925, Japanherath@hq.unu.edu

KATUMI MUSIAKE & SADAYUKI HIRONAKAInstitute of Industrial Science, University of Tokyo, 7-22-1 Roppongi, Minato-ku, Tokyo 106, Japan

Abstract The hydrological cycle of an urban catchment consisting of both natural and artificial flow components is modelled. Improvement of the water cycle with the use of infiltration systems that increase the groundwater recharge and reduce the flood flows is simulated considering feasible installation densities associated with urban renewal. Infiltration facility installation options are assessed and changes to the urban water environment over a decade and its restoration potential is modelled assuming that infiltration facilities can be implemented at the time of rebuilding or during new construction.Key words distributed hydrological modelling; flood reduction; groundwater recharge; infiltration facilities; low flow increase; urban hydrology; urbanization _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 303–310.

Method for satellite monitoring of water storage in reservoirs for efficient regional water management

JUN MAGOME

University of Yamanashi, Takeda 4-3-11, Kofu 400-8511, Japanj.magome@ccn.yamanashi.ac.jp

HIROSHI ISHIDAIRA & KUNIYOSHI TAKEUCHIGraduate School of Engineering, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511, Japan

Abstract Efficient use of water resources, at the basin-wide or regional scale, is the most important subject in integrated water resources management. For this purpose, it is necessary to monitor the variation of water storage in reservoirs within the region. We propose new methods of estimating water storage in reservoirs from satellite observations and digitized topographic data. These methods are applied to the Volta Lake of the Akosombo dam in Ghana. In this application, seasonal and inter-annual variations of reservoir storage are estimated, and the possibility of monitoring water storage is demonstrated. Key words Digital Elevation Model; reservoir storage; satellite altimeter; satellite image; Lake Volta _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 313–321.

Sustainability and groundwater

HUGO A. LOÁICIGADepartment of Geography, University of California, Santa Barbara, California 93106, USA hugo@geog.ucsb.edu

Abstract A theory of sustainable groundwater exploitation is presented in this article. The core of the article is a general formulation of the mathematical programming problem whose solution—when it exists—produces sustainable pumping rates. A simplified quadratic, linearly constrained, version of the general formulation is implemented and solved to calculate sustainable pumping rates in terms of diverse economic and hydraulic factors. The calculated pumping rates confirm the desirability of sustainable groundwater strategies judged by aquifer and economic performance. Key words game theory; groundwater; optimization; sustainable water development _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 322–326.

Water management budget as a basis for assessing water priorities in a catchment

BORIS FASHCHEVSKYDepartment of Environmental Management, International Sakharov Environmental University, Minsk 264 0800, Belarusborisf@tut.by

TATYANA FASHCHEVSKAYADepartment of Ecology, Ufa State Aircraft University, Ufa 51 24 12, Russia

Abstract In this paper new approaches are discussed for assessing priorities in the integrated water resources management of river basins, taking into account economic developments in the catchment as well as environmental factors. The approach is based on an analysis of the past and future water management budgets of the river basin. As an example the past water management budget and the environmental flows of the Volga River are considered.Key words environmental flows; past and future water management budgets; sanitary flows; transboundary rivers

_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 327–333.

A system for ecological and economic assessment of the use, preservation and restoration of urban water bodies: St Petersburg as a case study

SERGEI KONDRATYEVInstitute of Limnology of the Russian Academy of Sciences, Sevastyanova Str. 9, 196105 St Petersburg, Russiakondratyev@limno.org.ru

Abstract Urban water bodies reflect the level of environmental pollution in large cities. At present, only 2% of the urban water bodies in St Petersburg can be referred to as pure; 18% are contaminated, and 80% are polluted. This paper deals with the problem of choosing optimal strategies for urban water resources use without deterioration of the water quality and the ecological state of water bodies, while achieving economic returns for water users. A system for an ecological and economic assessment of the use, preservation, and restoration of water bodies is presented here. It consists of the following components: compilation of data in a Geographic Information System (GIS) environment; assessment of the investment appeal of the water bodies; assessment of the present suitability of the water bodies for possible alternative uses; optimization of the use of the water bodies based on mathematical modelling; estimation of the sensitivity of modelling results to changes in the water-body parameters; development of parameter change scenarios for maximizing the financial profit from water use; and analysis of financial profitability of water-use strategies. Part of the system has been applied to an analyses of optimal uses of the water bodies in St Petersburg.Key words ecological and economic assessment; preservation; restoration; urban water body; water quality; water use _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 334–340.

Sustainable water resources management in the Dragonja catchment, Slovenia

MITJA BRILLY University of Ljubljana, Faculty for Civil Engineering and Geodesy, Hajdrihova 28, Ljubljana, Sloveniambrilly@fgg.uni-lj.si

LIDIJA GLOBEVNIKWater Management Institute, Hajdrihova 28c, Ljubljana, Slovenia. lidija.globevnik@guest.arnes.si

Abstract The Dragonja River basin is situated right on the border between Slovenia and Croatia. Due to various political disturbances after the First and Second World Wars and poorly managed agriculture, the catchment depopulated in recent decades, leaving forests to develop in the abandoned agricultural fields. The changes in land use changed the hydrology of the catchment a great deal. Today, the area is developing again. Several conflict situations have arisen due to three doctrines promulgated by different parties. The first doctrine is the development of the area as a drinking water supply and food production resource on both the Slovenian and Croatian sides. The second is tourist development (airport extension, golf resort) of the valley. Due to its natural and landscape values, a plan to protect the greater part of the catchment as a landscape park has also been made. There are three main issues that should be considered to support sustainable management of the catchment’s water resources: How to preserve the area as an important natural and cultural heritage entity and to protect the water resources? How to satisfy water demands in the Slovenian coastal area? And, how to manage flood protection? The important tools are the management of river corridors and erosion spots to reasonably control the hydrological characteristics and to protect endemic and other important water flora and fauna species. Key words catchment management; Dragonja; experimental watershed; water policy _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at

Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 341–348.

The Chinese water resource: managing increasing demand and natural variations

JIANPING YANG, YONGJIAN DING & RENSHENG CHEN Cold and Arid Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, Chinajianping@ns.lzblaclcn

Abstract Most of the water supply in China is related to monsoon precipitation, which tends to be higher in the south of the country. Even in the drier north there is significant precipitation in both strong and ordinary monsoon years. However, there have been increasingly severe water shortages in north China due to greater demands caused by rapid economic development and associated increases in population, particularly in urban centres. This has been exacerbated since about 1980 by higher evaporation rates as a result of regional climatic warming. The mismatch between water supply and demand presently acts as a constraint on economic development in the north. However, there may still be severe floods during times of intense rainfall. Local water conservation measures include voluntary reductions of domestic water use, developing agricultural practices which reduce runoff loss, and more efficient use of water in industry. On the larger scale, plans have been made for a water transfer system to transfer surplus water from the southern part of the country to mitigate the severe shortages in the north. The eastern branch of the south–north water transfer project is presently under construction. The middle and western branches are still in the planning stage. It is essential that scientific water management practices be put in place for both imported and local water resources. This will best balance the time and space variations of water in China.Key words China; countermeasures; water resource _________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 349–357.

Impact of population growth and climate change on the quantity and quality of water resources in the northeast of India

U. C. SHARMACNRM, VPO Tarore, Bari Brahmnan – 181133, Jammu & Kashmir, Indiaucsharma2@rediffmail.com

Abstract The northeastern region of India is extremely rich in water resources but a continuous increase in human interference and mismanagement has rendered these resources in a fragile state. The region receives about 510 km3 of water as annual rainfall. It has two major river basins, the Brahmaputra and Barak, which drain 194 413 and 78 150 km2, with an annual runoff of 537.0 and 59.8 km3, respectively. The prevalence of shifting cultivation has resulted in deforestation and soil loss, causing silting of riverbeds and frequent occurrence of floods. Due to population pressure, more and more forest area is being cultivated, putting the whole ecology in peril. The declining trend in rainfall and frequent temperature fluctuations are a signal of climate change. The demand for water for domestic use has suddenly increased due to the rapid population growth and a change in the life style of the people. Water demand is high and the supply is not commensurate with it. Due to mismanagement of rainwater, about 3.586 106 ha of land has become prone to flooding. Further, water quality has also deteriorated due to its pollution by nitrates, chlorides and sulphates, and increased use of fertilizers and pesticides in an effort to increase crop productivity in the region. If the rate of population increase remains unabated, the water resources are likely to dwindle further and the quality of water is likely to deteriorate as well. Key words climate change; India; quantity and quality of water; population growth_________________________________________________________-Water Resources Systems—Hydrological Risk, Management and Development (Proceedings of symposium HS02b held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 281, 2003. p. 358–364.

World water use and water availability: trends, scenarios, consequences

IGOR A. SHIKLOMANOV & JEANNA А. BALONISHNIKOVA State Hydrological Institute (SHI), Second Line 23, St Petersburg 199053, Russiaishiklom@zb3627.spb.edu

Abstract New results of an assessment of future world water use obtained at SHI in 2001 are presented. Using data from Shiklomanov (2003) as well as new data on water use all over the world, a new scenario has been developed for sustainable global water use before 2025, i.e. a “Sustainable Development” scenario. This scenario is an alternative to that used in Shiklomanov (2003) which was developed in 1997 and is known as the “Conventional Scenario”. According to the Sustainable Development scenario, world water use until 2025 will be approximately stable. It will increase by about 6% before 2010, and then gradually decrease. Despite the fact that stabilization (and even a decrease of water use in the future) can significantly decrease the pressure on water resources, this will not greatly affect the specific water availability in most regions in the world due to population growth. Key words global water resources; water availability; water use