Considering Hydrological Change in Reservoir Planning and Management Editor: Andreas Schumann Co-editors: Vladimir Belyaev, Emna Gargouri, George Kuczera, Gil Mahé & Stephen Mallory IAHS Publ. 362 (2013) ISBN 978-1-907161-40-7, 214 + x pp. Price £61.00 This book provides an excellent overview of contemporary problems in reservoir management, from planning aspects of large multi-objective reservoirs and regarding small farm dams in Africa, to governmental matters, to sedimentation issues, to climate change impacts. Given the stochastic nature of hydrological conditions, the limited information available to characterize it and the multi-faceted targets of reservoir management, reservoir planning and operation are ambitious challenges for hydrologists and water managers. Reservoir management considers supply and demand. Demand includes the objectives of water management, but also the expectations of society, which develop with time; ecological targets for reservoir operation are now more important, social aspects and requirements are relevant and there are new constraints and objectives for operation of even older dams. The supply side has become more uncertain with increasing awareness of climate change causing growing concern about its impacts on the performance and reliability of existing and planned water management systems.
Transcript
Considering Hydrological Change in Reservoir Planning and
Management Editor: Andreas Schumann Co-editors: Vladimir Belyaev, Emna Gargouri, George Kuczera, Gil Mahé & Stephen MalloryIAHS Publ. 362 (2013) ISBN 978-1-907161-40-7, 214 + x pp. Price £61.00
This book provides an excellent overview of contemporary problems in reservoir management, from planning aspects of large multi-objective reservoirs and regarding small farm dams in Africa, to governmental matters, to sedimentation issues, to climate change impacts. Given the stochastic nature of hydrological conditions, the limited information available to characterize it and the multi-faceted targets of reservoir management, reservoir planning and operation are ambitious challenges for hydrologists and water managers. Reservoir management considers supply and demand. Demand includes the objectives of water management, but also the expectations of society, which develop with time; ecological targets for reservoir operation are now more important, social aspects and requirements are relevant and there are new constraints and objectives for operation of even older dams. The supply side has become more uncertain with increasing awareness of climate change causing growing concern about its impacts on the performance and reliability of existing and planned water management systems.
Preface
Reservoirs are fundamental components of water resources systems. By altering the temporal distribution of water resources, reservoirs bridge the gap between human-induced water demand and the variability of supply. Considering the stochastic character of hydrological conditions, the limited amount of information which is available to characterize it and the multifaceted targets of reservoir management, reservoir planning and operation is an ambitious challenge for hydrologists and water managers. Reservoir management has two aspects, the supply and the demand side. Under “demand” we summarize the objectives of water management, but also the expectations of societies. These expectations are variable in time. New, ecological targets for reservoir operation have become more and more important in the last decades, social aspects and requirements have to be considered in planning and new constraints and objectives for operation have become evident, even for dams, that were operated for decades previously. But not only the demands are changing; also the supply side has become more and more uncertain. The increasing awareness of climate change results in a growing concern about the impacts of such changes on the performance and reliability of existing and planned water management systems.
Nowadays, reservoir management is more challenging than ever. Reasons for this development are: the natural variability of available water resources seems to be increasing; the requirements of modern societies and the growing concern about negative side-
effects of reservoirs impose new targets and boundary conditions for planning and management;
the number and spatial distribution of reservoirs may result in the accumulation of negative impacts at larger spatial scales in river basins;
many reservoirs all over the world are strongly affected by sedimentation, reducing their storage capacities.
The International Commission of Water Resources Systems (ICWRS) of IAHS promotes research developments on the integration of all the phases of water resource protection, planning, design, management, operation and utilization. Reservoirs are located at the cutting edge of these interests. Thus ICWRS decided in 2011 at the IUGG Assembly in Melbourne to dedicate their next symposium to the topic “Considering hydrological change in reservoir planning and management”. The general aim of this symposium consisted of a presentation and discussion of new approaches for reservoir planning and management to improve the beneficial contribution of reservoirs within the context of Integrated Water Resources Management at the river basin scale. To ensure an integrative approach ICWRS was supported here by other IAHS commissions: the International Commission on Continental Erosion (ICCE), International Commission on Statistical Hydrology (ICSH) and the International Commission on Surface Water (ICSW). As convener I am deeply grateful for the substantial contributions of my co-convenors who were delegated from these commissions or are members of ICWRS: Vladimir Belyaev (Russia), Emna Gargouri (Tunisia), Yan Huang (China), George Kuczera (Australia), Gil Mahé (France), and Stephen Mallory (South Africa). My co-convenors supported me in an excellent way in reviewing the abstracts, selecting the oral presentations and preparing the full papers in close contact with the authors by suggesting improvements of their manuscripts and reviewing the alterations several times. As result of these efforts we are proud to have so many (in total 26) interesting papers which are published in this Red Book. The first paper, submitted by Viglione, Montanari & Blöschl, gives an introduction by summarizing contemporary problems of reservoir management. It is not surprising that this paper has two authors who are strongly involved in the activities of ICWRS, Alberto Montanari, who will be the president of this commission and Guenther Blöschl, its past president.The following 25 contributions can be grouped into different topics as follows:Problems of reservoir planning are discussed in eight papers. Here the questions of optimization of
operation rules for multi-site reservoir systems with multi-objectives, and their adaptation, are discussed. New ways to assess the performance of reservoirs for flood mitigation are demonstrated in one presentation. Non-conventional problems are discussed in two papers: the estimation of storage capacities of small farm dams, which have to be summarized in river basin planning, and the estimation of suitable sites for aquifer recharge.The operation of reservoirs is discussed in three papers. This part starts with a presentation of real-time dynamic control of the world’s largest water power plant, the Three Gorges Dam. The options to adapt operation to stochastic inflow forecasts are discussed and this part of the Red Book ends with a consideration of the frequency of decision making in updating operation schemes.Governmental problems are discussed in two contributions. One is dedicated to institutional design principles and the institutional framework for adaptation strategies of reservoir management. The other paper discusses the problems of limited skills of operators and the dependencies between the competencies of operators and the possible complexity of operation rules. Reservoirs and sedimentation Sedimentation is a major problem for sustainable reservoir management, especially in arid regions. In some parts of the world the yearly reduction of storage capacity by sedimentation is greater than the capacities of newly built reservoirs. In cooperation with the International Commission on Continental Erosion (ICCE) the sediment trapping effects of reservoirs are discussed in four papers. Two of them demonstrate the options to use tracers to estimate the sources of sediments and to analyse the ongoing sedimentation. Another paper discusses sedimentation problems of reservoirs in a region of the world where these processes are very important, in North Africa. Impacts of reservoirs on watersheds are manifold. A selection of these impacts are discussed in four papers of this Red Book: the problems of assessing the losses caused by evaporation from reservoirs which are used for hydro-power production, the impacts of small reservoirs on nutrient transport, the cumulative effects of small reservoirs downstream and the increase of fluctuations of discharges caused by operation of hydropower plants.Climate change and reservoir management The last section of this Red Book is dedicated to changing supply conditions. Climate change will result in changes of inflow for reservoirs, which can be assessed with high uncertainties only. Here five papers handle these problems. Half of them use the output of regional climate models to assess the changes of performance of existing and planned reservoirs; the other half considers the need and chances to adapt the reservoir management to such changes.This summary demonstrates the wide range of topics which are handled in this Red Book under the general theme “Reservoir Management”. It gives an excellent overview about contemporary problems in this field. I thank all authors who submitted their papers to this symposium.
Editor-in-Chief
Andreas SchumannRuhr University Bochum, Germany
Contents
Preface by Andreas Schumann iii
Challenges of reservoir planning and management in a changing world Alberto Viglione, Alberto Montanari & Günter Blöschl
1
1 Problems of reservoir planning
Research on the jointly optimal water-supply operation of a multi-reservoir system in Jinchang City of Shiyang River basin, China Tang Jiakai, Qian Ju, Han Xiaoyan, Liu Fen & Wan Liu
13
Improving the future performance and reliability of multi-reservoir systems by multi-objective optimization Ruben Müller & Niels Schütze
24
A simulation study on modifying reservoir operation rules: tradeoffs between flood mitigation and water supply Cherry May R. Mateo, Naota Hanasaki, Daisuke Komori, Kei Yoshimura, Masashi Kiguchi, Adisorn Champathong, Dai Yamazaki, Thada Sukhapunnaphan & Taikan Oki
33
Flood risk mitigation by reservoirs – application of multivariate statistical methods for risk assessments downstream Markus Schulte & Andreas Schumann
41
How flexibility in urban water resource decisions helps to manage uncertainty Mohammad Mortazavi, George Kuczera & Lijie Cui
49
Small farm dam capacity estimations from simple geometric relationships in support of the water use verification process in the Inkomati Water Management Area Tendai Sawunyama
57
Identification of suitable for aquifer recharge sites in Moura region (southern Portugal) Sina Abadzadesahraei
64
2 The operation of reservoirs
Real-time dynamic control of the Three Gorges Reservoir by coupling numerical weather rainfall prediction and flood forecasting Yun Wang, Hua Chen, Dan Rosbjerg, Henrik Madsen, Peter Bauer-Gottwein & Jinxing Wang
75
Impact analysis of long-term stochastic inflow prediction and its uncertainty on reservoir operation during drought situations Daisuke Nohara, Hiroko Miki & Tomoharu Hori
83
Reservoir operation and the frequency of decision making Stephen J. L. Mallory 91
3 Governmental problems
Ostrom’s institutional design principles and reservoir management: a study on 101
adaptation to climate variability and change Ana Cristina Souza da Silva, Carlos De Oliveira Galvão, Gerald Souza da Silva & Francisco de Assis de Souza Filho
Reservoir operating rules across a range of system complexities and degree of operator competencies Stephen J. L. Mallory, Jenny Pashki, Celiwe Ntul & Beason Mwaka
107
4 Reservoirs and sedimentation
Occupation du sol sur deux grands bassins d’Algérie et du Maroc, transport sédimentaire et barrages / Land-cover on two great basins in Algeria and Morocco, sediment transport and dams Gil Mahe, Mohamed Aderghal, Jamal Alkarkouri, Hamid Benabdelfadel, Djilali Bensafia, Telesphore Brou, Miloud Chaker, Mohamed Chikhaoui, Sylvie Coupleux, Remi Crouzevialle, Claudine Dieulin, Anas Emran, Mohamed Ezzaouini, Emmanuelle Goussot, Faiza Hallouz, Kenza Khomsi, Abdellah Laouina, Nadia Machouri, Veronique Maleval, Mohamed Meddi, Medare Nging, Olivier Planchon, Boualem Remini, Nathalie Rouche, Hasna Saadi, Mohamed Sfa, Mohamed Sinan, Maria Snoussi, Sabrina Taibi, Samir Toumi, Armand Tra Bi Samir Yahiaoui & Abdelaziz Zerouali
115
Using caesium-137 measurements to establish a sediment budget for the catchment of a small reservoir in southern Italy Paolo Porto, Desmond E. Walling & Carmelo la Spada
125
Effects of land use and climate changes on small reservoir siltation in the agricultural belt of European Russia Vladimir R. Belyaev, Valentin N. Golosov, Maxim V. Markelov, Nadezda N. Ivanova, Eugenia N. Shamshurina & Olivier Evrard
134
Impact of the Ertan Reservoir on reduction in sediment load in the lower Jinsha River, China Xinbao Zhang, D. L. Higgitt, Qiang Tang, Yi Long, Xiubin He & Anbang Wen
146
5 Impacts of reservoirs on watersheds
Water consumption from hydropower production: review of published estimates Tor Haakon Bakken, Ånund Killngtveit, Kolbjørn Engeland, Knut Alfredsen & Atle Harby
155
Impacts of hydropower station daily regulation on flow regimes downstream Chen Qihui, Yan Yan, Wang Yinli, Chen Yunyun & Qiu Liyin
161
Cumulative influence of small reservoirs on downstream flows in a semi-arid catchment: Merguellil, central Tunisia Andrew Ogilvie, Patrick Le Goulven, Christian Leduc, Roger Calvez, Mark Mulligan & Mohamed Ayachi
166
The effect of small impoundments on nutrient transport in a suburban watershed Yuta Shimizu, Shin-Ichi Onodera, Koki Onishi, Mitsuyo Saito & Masashi Yoshikawa
172
6 Climate change and reservoir management
Evaluation of reservoir operation flexibility under variable hydrological conditions with user defined rules Gokcen Uysal, Aynur Sensoy, A. Arda Sorman, Turker Akgun & Tolga Gezgin
181
Evaluation of changes in deficit volumes: support for protection of localities suitable for construction of reservoirs Martin Hanel, Ladislav Kašpárek, Martina Peláková, Adam Beran & Adam Vizina
187
Assessing the sensitivity of an Alpine reservoir to hydrological change and improving its operation by adaptive optimization Anghileri Daniela, Pianosi Francesca & Soncini-Sessa Rodolfo
193
Assessing the capacity of water resources to meet current and future water demands over the Ebro catchment (Spain) Marianne Milano, Denis Ruelland, Alain Dezetter,Julie Fabre, Sandra Ardoin-Bardin & Eric Servat
199
Assessing climate change impacts on operation and planning characteristics of Pong Reservoir, Beas (India) B. Soundharajan, Adebayo J. Adeloye & Renji Remesan
207
Key word index 213
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 1-10.
Challenges of reservoir planning and management in a changing world
ALBERTO VIGLIONE1, ALBERTO MONTANARI2 & GÜNTER BLÖSCHL1,3
1 Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Vienna, [email protected] Dipartimento di Ingegneria Civile, Ambientale e dei Materiali, University of Bologna, Italy3 Centre for Water Resource Systems, Vienna University of Technology, Vienna, Italy
Abstract Possible shifts of the rainfall regime in the next decades may have important implications for reservoir planning and management. Also, land-use change may alter the inflow regime to reservoirs, including the water and sediment dynamics. This paper reviews challenges to reservoir planning and management, and emerging approaches to address these issues in a changing world. Changing persistence of streamflow may increase the uncertainties of sizing reservoir storage, and changing floods may increase the uncertainties associated with spillway design. Short-term reservoir operation can be supported by ensemble forecasts and robust operation models to assess the uncertainties of management alternatives. Reservoir sedimentation is a major issue in many parts of the world which may be exacerbated by changes in catchment land use. It is argued that robust bottom-up approaches are needed that are vulnerability or resilience centred to complement the traditional top-down (scenario) approaches to reservoir planning and management.Key words reservoirs; flood estimation; climate change; runoff processes; long range dependence; sediment; reservoir operation and control; sustainability
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 13-23.
Research on the jointly optimal water-supply operation of a multi-reservoir system in Jinchang City of Shiyang River basin, China
TANG JIAKAI, QIAN JU, HAN XIAOYAN, LIU FEN & WAN LIUCollege of Earth and Environmental Sciences, Lanzhou University, 222 Southern Tianshui Road, Lanzhou 730000, Gansu, [email protected]
Abstract There are three reservoirs providing water for Jinchang City in Shiyang River basin, China. To resolve water scarcity problems, a mathematical model of jointly optimal operation of a multi-reservoir is established, which is based on the minimum amount of water shortage as the aim function. Processes of optimal operation of three reservoirs are calculated according to in–out discharge data from 1990 to 2007 using the Genetic Algorithm method. The result indicates that the total amount of water supply reaches 633 hm3 in Jinchang City through the operation system, the ratio of water shortage decreases from 28.1% to 16.1%. In addition, an ANN model is proposed for optimal operation. Comparing with the Genetic Algorithm method, the ANN model is better, with a smaller simulation error (<8%). The pattern of jointly optimal operation of a multi-reservoir can provide a basis for the optimal allocation of water resources in Jinchang City.Key words reservoirs operation; genetic algorithm; artificial neural network; water supply
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 24-32.
Improving the future performance and reliability of multi-reservoir systems by multi-objective optimization
RUBEN MÜLLER & NIELS SCHÜTZE
Institute of Hydrology and Meteorology, Dresden University of Technology, 01069 Dresden, [email protected]
Abstract Current climate circulation models simulate a climate change-induced decreasing amount of precipitation in the region of Saxony (Germany) in summer. Consequently, the operation of reservoirs has to consider decreasing inflows, more severe drought periods, as well as increasing demands for water. In order to adapt to these new pressuring conditions and to meet the future demands of all water sectors and simultaneously to provide flood protection, new management strategies for the reservoirs are required. This study combines multi-objective optimization and Monte Carlo simulation for finding effective management strategies for multi-purpose multi-reservoir systems. To achieve robust operations, a new framework is developed which comprises: (i) the physically-based rainfall–runoff model, (ii) a time series model for the generation of a large number of synthetic inflow time series, (iii) a comprehensive reservoir model, and (iv) an adapted multi-objective optimization algorithm and advanced visualization methods for a compact presentation of the results for the decision maker. In a real case application, the new framework is used to find operating rules of a multi-purpose multi-reservoir system in the Ore Mountains, Germany. The overall robustness of the multi-reservoir system operation is quantified and trade-offs between management goals and reservoir utilizations are shown.Key words multi-purpose multi-reservoir system; multi-objective optimization; rule curves; visualization
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 33-40.
A simulation study on modifying reservoir operation rules: tradeoffs between flood mitigation and water supply
CHERRY MAY R. MATEO1, NAOTA HANASAKI2, DAISUKE KOMORI1,
1 Institute of Industrial Science, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, 153-8505 Tokyo, [email protected] National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan3 Office of Water Management & Hydrol., Royal Irrigation Department,811 Samsen Rd, Dusit, Bangkok 10300, Thailand4 School of Geographical Sciences, University of Bristol, University Road, Clifton, Bristol BS8, UK
Abstract A simulation model was used to evaluate two proposed reservoir operation rules in Bhumibol and Sirikit reservoirs in the Chao Phraya River Basin. H08, an integrated hydrology and water resources model, was combined with CaMa-Flood, a river routing model considering inundation dynamics, to simulate the impacts of reservoir operation on the river basin. Simulated reservoir inflows were used as input to the reservoir operation module coupled with H08. The inclusion of CaMa-Flood in the system allows the assessment of impacts of reservoir operation on inundation within the entire river basin. It was found that hedging significantly reduces the occurrence of the reservoir emptying during dry seasons. A low linear storage constraint, set three months before the onset of the rainy season, significantly reduces the reservoir overflows. The simulation framework developed would be useful in designing optimal reservoir operation rules that are effective for mitigating both flood and drought damages.Key words integrated hydrology and water resources model; H08; CaMa-Flood; balancing flood mitigation and water supply provision; Bhumibol and Sirikit Reservoir; Chao Phraya River Basin
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013)41-48
Flood risk mitigation by reservoirs – application of multivariate statistical methods for risk assessments downstream
MARKUS SCHULTE & ANDREAS SCHUMANNInstitute of Hydrology, Water Resources Management and Environmental Engineering, Ruhr University Bochum, D-44780 Bochum, [email protected]
Abstract A flood is an extreme hydrological event which is characterized by several correlated variables (flood
peak, volume and duration). The efficiency of flood reservoirs is strongly affected by the event-specific combination of the two correlated characteristics flood peak and flood volume. As flood events with unusual combinations of these characteristics can be more critical than a single design flood, growing emphasis is given to multivariate frequency analysis to consider this uncertainty. Here a new approach to assess the efficiency of a reservoir for downstream flood risk mitigation which considers interactions of tributaries is discussed. It is shown that coincidences of floods which are originating from different sub-basins have a large impact on the efficiency of a reservoir. As the interaction of tributaries depends strongly on the spatial and temporal distributions of rainfall, the event-specific flood risk mitigation by a reservoir stays uncertain. This uncertainty can be described by multivariate statistical analyses. Here it is shown how multivariate statistics can be used to locate reservoirs within river basins under consideration of their capacity to mitigate floods downstream. Key words flood risk; multivariate statistic; copulas; coincidence
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 49-56.
How flexibility in urban water resource decisions helps to manage uncertainty?
MOHAMMAD MORTAZAVI, GEORGE KUCZERA & LIJIE CUISchool of Engineering, University of Newcastle, Callaghan, NSW 2308, [email protected]
Abstract Uncertainty in future climate change and demand presents a significant challenge to the planning and management of urban water supply systems. One of the approaches to deal with uncertainty is to break large investments into a series of smaller decisions. In fact, spreading investments over time lets decision makers respond to unfolding contingences. This study considers the issue of identifying Pareto-optimal solutions for urban water supply that are robust in the face of uncertain future demand. The approach is based on the simulation of three plausible future demand scenarios to allow expected economic performance to be traded off against the variability in performance. A case study demonstrates the feasibility of this approach for a complex urban water supply system. The primary objective is to minimize the expected present worth of costs associated with infrastructure decisions, operating rules and drought contingency plans. By introducing a second objective which minimizes the difference in present worth costs across future demand scenarios, the trade-off between efficiency and robustness is identified. The results show that a significant change in investment and operating strategy occurs when the decision maker expresses a stronger preference for robustness.Key words multi-objective optimization; demand growth; urban water management; scheduling
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 57-63.
Small farm dam capacity estimations from simple geometric relationships in support of the water use verification process in the Inkomati Water Management Area
TENDAI SAWUNYAMAInstitute for Water Research, Rhodes University, PO Box 94 Grahamstown, 6140, South [email protected]
Abstract Within the Inkomati Water Management Area in South Africa, there are a large number of small farm dams. While they are of economic value, the management of these dams raises key questions for water managers. As a result, a study to verify the storage of all farm dams has been initiated, as part of the development of an integrated river-basin-scale modelling system. The initial step towards this goal is the development of a tool to estimate the capacity of small farm dams from simple geometric relationships. The methodology used is the Geographical Information System (GIS)-based approach, with dam geometries such as the surface area, fetch and width being estimated. The results show that there is a large variation in farm dam geometries resulting in a wide range of possible storage capacities for any given surface area and that farm dam geometries tend to vary between sub-catchments.Key words small dam capacities; Geographical Information System; Inkomati Water Management Area, South Africa
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 64-72.
Identification of suitable sites for aquifer recharge in Moura region (southern Portugal)
SINA ABADZADESAHRAEIDepartment of Natural Resources and Environmental Studies, University of Northern British Columbia, 3333 University Way, Prince George, British Columbia V2N 4Z9, Canada [email protected]
Abstract Recent research found a decrease in the recharge of the karstic Moura-Ficalho (MF) aquifer and called for further research on appropriate mitigation strategies to reverse desertification. This research identifies areas where natural recharge has occurred within the MF aquifer and where recharge could be increased through Managed Aquifer Recharge (MAR) techniques. Topographic maps and hydraulic heads were constructed using Geographic Information System (Arc GIS) software to identify sites with sufficient ground storage space for artificial recharges. Data analysis found the northern, western, and eastern margins of the Moura region unsuitable for recharge due to impermeable layers, insufficient groundwater storage space, and insufficient water resources. The central region of the MF was also unsuitable as the groundwater and hydraulic potential throughout the aquifer could not be increased. The southern margin was shown to be most suitable for groundwater recharge as it had adequate groundwater storage space and an available water supply.Key words Moura-Ficalho (MF) aquifer system; sink holes; natural recharge; Managed Aquifer Recharge (MAR); Geographic Information System (Arc GIS)
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013)75-82.
Real-time dynamic control of the Three Gorges Reservoir by coupling numerical weather rainfall prediction and flood forecasting
YUN WANG1, HUA CHEN1,2, DAN ROSBJERG2, HENRIK MADSEN3, PETER BAUER-GOTTWEIN2 & JINXING WANG4
1 State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China 2 Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, DK-2800 Kongens Lyngby, [email protected] DHI Water-Environment-Health, Agern Allé 5, DK-2970 Hørsholm, Denmark4 Hydrological Forecast Center, Ministry of Water Resources, Beijing 100053, China
Abstract Combining numerical weather rainfall prediction and flood forecasting to enhance forecast accuracy of inflow and extend the lead-time can effectively improve reservoir operation mode. In this study, the Regional Spectrum Model (RSM), which is developed by the Japan Meteorological Agency, was used to forecast rainfall with 5 days lead-time in the upper region of the Three Gorges Reservoir (TGR). The Xinanjiang Model was applied to forecast inflow to the TGR. In terms of relative error of inflow, relative error of flood peak and time difference of flood peak the performance of these combined forecasts was compared with that of a forecast based on using observed inflow and assuming that no further rain would fall. Taking the largest flood event in 2012 as an example, all inflow forecasting results were used to implement real-time dynamic control of the FLWL of the TGR. Compared with the designed operation rule, operation results showed that the dynamic control scheme significantly improved hydropower generation without increasing flood risk.Key words numerical weather rainfall prediction; flood forecasting; flood limited water level; real-time dynamic control; Three Gorges Reservoir
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 83-90.
Impact analysis of long-term stochastic inflow prediction and its uncertainty on reservoir operation during drought situations
DAISUKE NOHARA1, HIROKO MIKI2 & TOMOHARU HORI1
1 Disaster Prevention Research Institute, Kyoto University, Gokasho, Uji, 611-0011, [email protected] Graduate School of Engineering, Kyoto University, Kyoto Univ. Katsura Campus, Nishikyo, Kyoto, 615-8540, Japan
Abstract Impacts of long-term stochastic inflow predictions (SIPs) and their uncertainties on reservoir operation for water supply under drought situations are analysed and discussed in this study. Multiple sets of SIPs are pseudo-randomly generated with five-day resolution for three months, arbitrarily changing the two kinds of prediction’s uncertainty, namely reliability and discrimination, for a comprehensive analysis of the impact of the SIP. Monte Carlo simulations of long-term reservoir operation for water supply under drought situations are then conducted considering generated multiple SIPs with various uncertainties. The proposed analysing method was applied to an assumed reservoir whose data was derived from Sameura Reservoir in Japan, demonstrating expected impacts of SIPs and their uncertainties on the long-term reservoir operation, and giving a suggestion as to what type of uncertainty in SIP is more important in real-time reservoir operation for more effective drought management.Key words stochastic inflow prediction; reservoir operation; drought management; impact analysis; uncertainty; reliability; discrimination; Monte Carlo simulation
___________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013)91-98
Reservoir operation and the frequency of decision making
STEPHEN J. L. MALLORYInstitute for Water Research, Rhodes University, 492 Dawn Road, Lynnwood, Pretoria, South [email protected]
Abstract Restricting water use during times of drought is an accepted practice in many arid countries to ensure the sustainable use of reservoirs and large systems of interlinked reservoirs. The timing and magnitude of restrictions, referred to in this paper as an operating rule, has been investigated in terms of how often the decision is made as to whether or not to apply restrictions at any point in time. The current practice in South Africa is to make a decision once a year based on the state of storage in the reservoir or system of reservoirs together with stochastic projections of likely inflows over the next 5 to 10 years. The question that is explored in this paper is whether there is an advantage in making this decision more frequently. This analysis has been carried out by adapting an existing water resources model to be able to toggle between annual and monthly decisions. Several hypothetical systems were modelled using both annual and monthly decisions based on the state of storage of the system. The systems modelled varied from those with large carry-over periods, or long critical periods, to those with short critical periods. Multiple users with high and low risk profiles were included in the simulations. The outcome of these simulations in terms of the volume of water supplied to high and low risk users was recorded for each simulation. The conclusion reached is that there is a significant benefit to users from systems with short critical periods to make more frequent decisions on water restrictions rather than an annual decision. Based on this conclusion a recommendation is made about the appropriate frequency of decision making based on the type of system and the risk profile of the user.Key words Reservoir Operation; assurance of supply; water restrictions; hedging
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 101-106
Ostrom’s institutional design principles and reservoir management: a study on adaptation to climate variability and change
ANA CRISTINA SOUZA DA SILVA1, CARLOS DE OLIVEIRA GALVÃO1, GERALD SOUZA DA SILVA2 & FRANCISCO DE ASSIS DE SOUZA FILHO3
1 Federal University of Campina Grande – UFCG, Campina Grande, [email protected] Water Management Agency of the State of Paraiba – AESA, João Pessoa, Brazil3 Federal University of Ceará – UFC, Fortaleza, Brazil
Abstract Elinor Ostrom’s institutional design principles for common pool resources management were refined and extended recently by water resources researchers for studying the governance of adaptation to climate change. Regarding hydrological variability and change and their influence on the management of water reservoirs, this paper shows how Ostrom’s theory can be helpful to better analyse the institutional framework that supports the governance of these systems. This paper analyses the political process of generating adaptation strategies for the management of water resources of one particular reservoir located in the drought-prone semi-arid region of Brazil. The work was based on documental analysis of water resources policy frameworks and plans, as well as past experiences in coping with extreme drought events. The application of Ostrom’s extended principles allowed the suggestion of relevant institutional proposals for a more robust management of the analysed reservoir.Key words water policy; semi-arid; drought; reservoir; climate variability; climate change
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 107-112.
Reservoir operating rules across a range of system complexities and degree of operator competencies
STEPHEN J. L. MALLORY1, JENNY PASHKIN2, CELIWE NTULI2 & BEASON MWAKA2
1 IWR Water Resources, 492 Dawn Road, Lynnwood, Pretoria, South [email protected] Department of Water Affairs, Private Bag X313, Pretoria, South Africa
Abstract South Africa, as with most developing countries, has historically focused its efforts on developing operating rules for reservoirs and systems of interlinked reservoirs on large schemes which support major economic zones. In order to achieve a more equitable approach to water resources management, South Africa embarked on a process to develop operating rules for the smaller reservoirs and systems supplying water to towns and rural areas. This process entailed developing operating rules for over 100 dams across the country. This paper presents some of the lessons learnt from this process. One of the main conclusions is that the operating rules need to be adapted to the level of sophistication that can be accommodated by the reservoir operators. In its simplest form the operating rule is a description of actions to be undertaken under various situations. At the other extreme operating rules consist of complex decision support systems which include stochastic simulation models which carry out simulations every month and advise users of the risk of entering a restriction zone in future so that informed decisions can be made. This could include advice on transfer of water from other sources, the conjunctive use of surface and groundwater, or using desalination plants during serious droughts. A range of example operating rules are presented which cover the scope of this project. The conclusion reached in this paper is that a systematic approach is required to identify the type of operating rules that are applicable in any given situation, and a possible systematic approach is presented.Key words Reservoir Operation; water restrictions; decision support systems
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013). 115-124
Occupation du sol sur deux grands bassins d’Algérie et du Maroc, transport sédimentaire et barrages
1 HydroSciences Montpellier, [email protected] 2 Université Mohammed 5, Rabat, Maroc3 Université de Kenitra, Maroc4 Direction de la recherche et de la Planification de l’Eau, Rabat, Maroc5 Université Saad Dahlab Blida, Algérie6 Université de la Réunion, France7 Institut Agronomique et Vétérinaire Hassan II, Rabat, Maroc 8 Université d’Artois, Arras, France9 Université de Limoges, France10 Agence du Bassin Hydraulique du Bouregreg et de la Chaouia, Ben Slimane, Maroc11 AgroParisTech, Paris, France 12 Ecole Nationale d’Hydraulique de Blida, LGEE, Blida, Algérie13 Météorologie Nationale, Casablanca, Maroc14 LISAH, Montpellier, France15 Ecole Hassania des Travaux Publics, Casablanca, Maroc16 Université de Cocody, Abdijan, Côte d’Ivoire
Résumé En Afrique du nord, le comblement des retenues par les sédiments est un problème majeur pour les barrages. La relation avec l’évolution de l’occupation des sols et le changement climatique est mal connue. L’hypothèse est que les changements d’usage des sols et l’augmentation de la pression agricole, associés à une diminution durable des pluies, fragilisent les sols et les rendent plus sensibles à l’érosion. Deux grands basins versants sont étudiés dans le cadre du programme SIGMED (approche spatialisée de l’impact des activités agricoles sur les transports solides et les ressources en eau de grands bassins versants): l’oued Bouregreg au Maroc et l’oued Mina en Algérie. Un des objectifs est de suivre l’évolution de l’occupation du sol pour identifier les zones sensibles et de comparer avec la sédimentation dans les barrages. L’érosion en provenance des versants immédiats des barrages pourrait constituer une source majeure en sédiments dans les retenues, et être le lieu privilégié d’opérations de protection et de restauration de la végétation, pour prévenir les risques de comblement.Mots clés Bouregreg; Mina; Maroc; Algérie; SIGMED; sédiments; barrage; occupation du sol; érosion
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 125-133
Using caesium-137 measurements to establish a sediment budget for the catchment of a small reservoir in southern Italy
PAOLO PORTO1,2, DESMOND E. WALLING2 & CARMELO LA SPADA1
1 Dipartimento di Agraria, Università degli Studi Mediterranea, Località Feo di Vito, Reggio Calabria, [email protected] College of Life and Environmental Sciences, University of Exeter, Amory Building, Rennes Drive, Exeter EX4 4RJ, UK
Abstract Predicting the expected life of a reservoir and assessing the potential for increasing this life is a great challenge for the hydraulic engineer, as it involves predicting the sediment input to the reservoir. The rate of sedimentation in a reservoir will primarily reflect the amount of sediment eroded from the upstream catchment and the efficiency of sediment delivery to the reservoir. When fine particles dominate the soil texture of a catchment and the land use is conducive to erosion, a large proportion of the soil loss can commonly be ascribed to sheet erosion from the slopes. The fallout radionuclide caesium-137 (137Cs) has been increasingly used to document rates of soil loss by sheet erosion in recent years, both as an alternative to conventional measurements and for calibrating physically-based soil erosion models. This paper reports an example of the application of the 137Cs technique in a medium-scale (14.8 km2) catchment upstream of a small reservoir in southern Italy, aimed at
assembling information on soil erosion and redistribution on the catchment slopes, and flood plain sedimentation rates, in order to establish a catchment sediment budget. Data available from sediment (turbidity) monitoring undertaken at the catchment outlet prior to the construction of the reservoir have been used to estimate the catchment sediment yield. This estimate has been combined with the information provided by the 137Cs measurements, to establish a sediment budget for the catchment. The sediment budget provides a valuable tool for understanding sediment inputs to a reservoir and their sensitivity to climate change, and for planning and implementing sediment control measures within the catchment, in order to reduce reservoir sedimentation rates. Key words reservoirs; caesium-137; erosion rates; sedimentation rates sediment budget; Italy
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 134-145.
Effects of land use and climate changes on small reservoir siltation in the agricultural belt of European Russia
VLADIMIR R. BELYAEV1, VALENTIN N. GOLOSOV1,2, MAXIM V. MARKELOV1, NADEZDA N. IVANOVA1, EUGENIA N. SHAMSHURINA1 & OLIVIER EVRARD3
1 Laboratory of Soil Erosion and Fluvial Processes, Faculty of Geography, Lomonosov Moscow State University, Leninskie Gory, GSP-1, Moscow 119991, [email protected] Institute of Ecology and Geography, Kazan (Volga region) Federal University, 18, Kremlevskaya Street, Kazan 420008, Russia3 Laboratoire des Sciences du Climat et de l’Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Centre de Recherche du CNRS, Avenue de la Terrasse, 91 198 Gif-sur-Yvette Cedex, France
Abstract Small reservoirs of agriculture-dominated areas experience severely increased sediment input caused by soil erosion on cultivated slopes, also accompanied at some locations by gully erosion. This causes rapid decrease of the reservoir water storage and shortened periods of functioning. In this paper we discuss several examples of the 137Cs-based short-term siltation chronology of small reservoirs located in different landscape zones within the agricultural belt of European Russia. From two to four time marks could have been established in 137Cs depth distribution curves constructed from detailed depth-incremental sampling of reservoir infill sediment, allowing reconstruction of sediment microstratigraphy and deposition rates. In combination with other independent information sources this provides insight on the relative importance of recent land use changes and climatic variability in controlling sediment delivery within small agriculture-dominated fluvial systems. In combination with sediment redistribution studies, it has become possible to construct closed sediment budgets for catchments of several reservoirs and make a quantitative assessment of sediment delivery variability. Such information is important for appropriate design and management of small agricultural reservoirs in Russia.Key words small reservoirs; siltation; agricultural land; soil erosion; sediment delivery; 137Cs depth distribution; microstratigraphy; deposition rates; climate changes; European Russia
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 146-152
Impact of the Ertan Reservoir on reduction in sediment load in lower Jinsha River, China
XINBAO ZHANG1, D. L. HIGGITT2, QIANG TANG1,3, YI LONG1, XIUBIN HE1 & ANBANG WEN1 1 Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China [email protected] Department of Geography, National University of Singapore, 118670 Singapore 3 University of Chinese Academy of Sciences, Beijing 100049, China
Abstract The potential effect of dam construction on fluvial hydrological processes related to changes in streamflow discharge and sediment load has been widely understood. However, the underlying mechanism may
not be homogeneous, depending on storage capacity, operation mode and catchment geographic features. Gauging evidence demonstrates that sediment load in the lower Jinsha River has been reduced considerably since 1998 when impoundment of the Ertan Reservoir commenced. However, the observed sediment reduction is much greater than the sediment load discharged into the reservoir. The present paper discovered that reduction of in-stream sediment transportation capacity during major flood events resulting from water impoundment played an important role in riverine sediment regulation, in addition to the well-documented sediment trapping effect.Key words sediment yield; dam construction; sediment transport capacity; trapping effect; Ertan Reservoir; Jinsha River
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 155-160.
Water consumption from hydropower production: review of published estimates
1 Norwegian University of Science and Technology, Trondheim, [email protected] SINTEF Energy Research, Trondheim, Norway
Abstract This paper presents an extensive review of all known published literature on water consumption from hydropower plants. The paper documents that the estimates show a large variation, from close to zero m3/MWh to more than 3500 m3/MWh, where the maximum values are far beyond the values published by IPCC (2011). The highest values are from irrigation reservoirs with very limited hydropower production. The review reveals that there is no consistent methodological approach in place, which is a major obstacle in making a fair comparison between hydropower projects, and ultimately between technologies. Key words energy water nexus; hydropower; water consumption; water footprint; review of estimates
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 161-165.
Impacts of hydropower station daily regulation on flow regimes downstream
CHEN QIHUI, YAN YAN, WANG YINLI, CHEN YUNYUN & QIU LIYINCollege of Water Resources and Hydrology, Hohai University, Nanjing 210098, Chinachenqh @ hhu.edu.cn
Abstract A hydropower station’s daily regulation may change river natural daily runoff and river habitat characteristics, and thus could influence the composition, structure and function of the biocommunity. Based on characteristics of the hydropower station’s daily regulation and concepts of ecohydrological parameters, hydrologic indices on the basis of the time series of hourly water level were applied to elucidate the influences of hydropower station daily regulation on streamflow. The attributes of those daily flow pulses, such as magnitude, rate of change, timing and duration, generated by the hydropower station, were quantified. The results of the study provides references for the assessment of impacts of altered flow regimes on riverine ecosystems due to hydropower stations’ daily regulation. Key words hydropower station’s daily regulation; flow regime; hydrological indices
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 166-177
Cumulative influence of small reservoirs on downstream flows in
a semi-arid catchment: Merguellil, central Tunisia
ANDREW OGILVIE1,2, PATRICK LE GOULVEN1, CHRISTIAN LEDUC1, ROGER CALVEZ1, MARK MULLIGAN2 & MOHAMED AYACHI3
1 IRD, UMR G-eau, 361 rue Jean-François Breton, BP 5095, 34196 Montpellier Cedex 5, [email protected] Department of Geography, King's College London, Strand, London WC2R 2LS, UK3 Commissariat Régional au Développement Agricole, Cité Sidi Layouni, Kairouan 31000, Tunisia
Abstract Despite small reservoirs becoming increasingly widespread across many semi-arid regions, their cumulative influence in large catchments remains poorly understood. Part of the difficulty lies in distinguishing their effect over concurrent human and climatic processes which also affect runoff. In the Merguellil catchment, in semi-arid central Tunisia, detailed analysis of 114 events revealed a 45% decrease in the runoff coefficients of rainfall events under 40 mm occurring on similar conditions of land cover and soil humidity, following the development of reservoirs and contour benches. These are capable of reducing annual flows by 25–30%. However the major decrease in catchment runoff observed after their construction is shown to be largely related to climatic fluctuations. Annual runoff variations were weakly correlated with total rainfall, but driven by changes in the number of rainfall events over 15 mm (5–6 per year) and in their circumstances, notably rainfall intensity, crop cover and antecedent soil moisture. Key words small reservoirs; water harvesting; runoff coefficients; rainfall events; climate influence; semi-arid zones
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 172-178.
The effect of small impoundments on nutrient transport in a suburban watershed
YUTA SHIMIZU1, SHIN-ICHI ONODERA1, KOKI ONISHI1, MITSUYO SAITO2 & MASASHI YOSHIKAWA1
1 Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japany-shimizu @ hiroshima-u.ac.jp 2 Center for Marine Environmental Studies (CMES), Ehime University, 2-5, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
Abstract The objective of this study was to confirm the effect of small impoundments on nutrient transport on a catchment scale. We examined the effect using the ratio that dissolved nitrogen (DN) is divided by Cl -. The ratio increased in the summer season and decreased in the winter season at the outlet of the impoundments. The reason for decreasing of the ratio may be explained by the decline of DN concentration, by assimilation or denitrification. The relation between residence time and magnitude of nitrate removal showed that long residence time can lead to greater reduction of nitrate. However, DN was produced in larger impoundments and sediment interaction may occur as a result. Therefore, smaller impoundments may be more effective for nitrate attenuation than larger ones. From the results, small impoundments management is important for better water environments in a watershed in future, because it has a potential for nutrient removal that can be used more positively for improving water quality at a local scale.Key words small impoundment; residence time; nitrogen removal
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 181-186.
Evaluation of reservoir operation flexibility under variable hydrological conditions with user defined rules
1 Anadolu, University Iki Eylul Campus, Civil Engineering Department, Eskisehir 26555, Turkey
[email protected] Akifer Su Hizmetleri Ltd. Sti, Izmit Icme Suyu Aritma Tesisleri, Baskiskele, Kocaeli 41190, Turkey
Abstract The aim is to operate Yuvacık Reservoir without any flood and drought risk for long-term water supply, to raise the reservoir elevation as high as possible before the inflow recession period starts, which is generally observed in early May. User-defined operating rules are determined, taking hydrological conditions (snow potential, inflow, season and current level) into consideration to construct the simulation model with five years of daily data in which a drought and a wet year are included. In this study, a robust simulation model is analysed for 2001–2005 to investigate the reservoir operation flexibility. In conclusion, the extended period results show that the simulation model is sensitive to the hydrological changes and is applicable for real time operation of the reservoir.Key words HEC-ResSim; long term; reservoir simulation model; variable hydrological conditions
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 187-192.
Evaluation of changes in deficit volumes: support for protection of localities suitable for construction of reservoirs
MARTIN HANEL1,2, LADISLAV KAŠPÁREK1, MARTINA PELÁKOVÁ1, ADAM BERAN1,2 & ADAM VIZINA1,2
1 T. G. Masaryk Water Research Institute, p.r.i., Podbabská 30, 160 00 Prague, Czech Republic [email protected] 2 Faculty of Environmental Sciences, Czech University of Life Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
Abstract Climate change scenarios for the Czech Republic indicate an increase in frequency of deficit events and volume of deficit discharges. The Czech water management legislation considers a number of protected areas potentially suitable for construction of reservoirs for flood protection and/or improving the water balance in the drought periods. In the present study we use hydrological modelling to quantify the volume of the deficit discharges as projected by an ensemble of transient regional climate model simulations. The changes in the deficit volumes are assessed using a simple statistical model considering the generalized extreme value distribution for the deficit volumes. Derived deficits are subsequently compared to the potential volume of the considered reservoirs. It is concluded that for many regional climate model simulations the changes in deficits are comparable or larger than the available volume of water in the reservoirs. The uncertainty is, however, large.Key words deficit volumes; statistical model; regional climate model simulations
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 193-198.
Assessing the sensitivity of an Alpine reservoir to hydrological change and improving its operation by adaptive optimization
ANGHILERI DANIELA, PIANOSI FRANCESCA & SONCINI-SESSA RODOLFODipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Via Ponzio 34/5, 20133, Milano, [email protected]
Abstract The “scenario-based” approach traditionally used in planning and management of water systems can fail to cope with the non-stationary nature of hydro-climatic conditions and the deep uncertainty in their prediction. In this paper, we contribute to the development of new analytical tools for reservoir management, and specifically for: (i) assessing the sensitivity of water resource systems to hydrological changes; (ii) increasing the adaptation capacity of reservoir systems by adaptive optimization. We use the multipur pose regulated Lake Maggiore, at the border between Switzerland and Italy, as a case study. The application of trend detection techniques shows that significant hydrological changes are already undergoing in the investigated watershed. Historical time series can thus be exploited as a testing ground of adaptation strategies, for instance adaptive optimization of the lake operating policy. Simulation results show that the adaptive approach improves the system performances with respect to the scenario-based one in terms of irrigation supply, while it performs
slightly worse for flood control.Key words water resources management; climate change; adaptation; trend analysis
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 199-206
Assessing the capacity of water resources to meet current and future water demands over the Ebro catchment (Spain)
1 UM2, UMR HydroSciences Montpellier, Place E. Bataillon, 34395 Montpellier Cedex 5, [email protected] CNRS, UMR HydroSciences Montpellier, Place E. Bataillon, 34395 Montpellier Cedex 5, France3 IRD, UMR HydroSciences Montpellier, Place E. Bataillon, 34395 Montpellier Cedex 5, France4 Plan Bleu, 15 rue Beethoven, 06560 Valbonne Sophia-Antipolis, France
Abstract Since the late 1970s, a negative trend in river discharge has been observed at the outlet of the Ebro catchment (Spain). This can be attributed to a decrease in mean precipitation, a rise in mean temperature, and a water consumption increase. Moreover, over 230 storage-dams were built to regulate river discharge in the basin. An integrated water resource modelling framework was developed to assess whether future water demands could be satisfied under both climatic and anthropogenic changes. This approach confronts water supplies, generated by a conceptual hydrological model and by a storage-dam module, and water demands and environmental flow requirements. Water demands are evaluated for the most water-demanding sectors, i.e. the agricultural and domestic sectors. The capacity of water resources to meet demands is assessed through a water allocation index. Results show growing competition among users, especially during the summer season. They also highlight the interest of integrated modelling with regard to providing complete analysis of water resources’ capacity to meet water demands under complex evolution scenarios in order to support decision-making.Key words Ebro catchment; water supply; water demands; water allocation; storage-dam modelling; integrated modelling
_____________________________________________________________________________________________________Considering Hydrological Change in Reservoir Planning and Management Proceedings of H09, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 (IAHS Publ. 362, 2013) 207-262.
Assessing climate change impacts on operation and planning characteristics of Pong Reservoir, Beas (India)
B. SOUNDHARAJAN1, ADEBAYO J. ADELOYE1 & RENJI REMESAN2
1 School of the Built Environment, Heriot-Watt University, Edinburgh, [email protected] School of Applied Sciences, Cranfield University, Cranfield, UK
Abstract In India, there is a considerable change in both spatial and temporal patterns of the monsoon rainfall, resulting in reduced crop yields and increasing uncertainty in the agriculture-based livelihoods of the rural population. Changes in rainfall, temperature and evapotranspiration are affecting water resources availability and demands, and hence the performance of irrigation water supply facilities such as reservoirs and canal diversions. In order to accommodate these changes in the water resources situation, there must be substantial improvement in water use and management efficiency but this can only be meaningfully done if the impact of climate change and variability is quantified. Consequently, this work has investigated the effects of climate change and variability on irrigation water security in Beas River basin in India by characterising the yield and performance (reliability, resilience and vulnerability) of the associated Pong Reservoir for current (baseline) and climate-change perturbed future horizons. Climate change perturbations based on CGCM3.1 (third generation coupled GCM) for the A1B and B2A IPCC SRES socio-economic scenarios, appropriately downscaled to basin scale were used. The whole analysis was conducted within a Monte Carlo simulation framework, thus enabling the variability and uncertainty associated with each of these variables to also be quantified. The results show that future inflow series to the Pong will exhibit higher inter-annual variability than the baseline, necessitating increased reservoir capacity to meet existing irrigation water demands. In terms of overall performance, while the reliability (both volume- and time-based) was largely unaffected by climate change, the resilience significantly deteriorated especially for the A1B scenario. There were also noticeable changes in the rule curves
