Interval-parameter Two-stage Stochastic Semi-infinite Programming: Application to Water Resources Management under Uncertainty

In this study, an interval-parameter two-stage stochastic semi-infinite programming (ITSSP) method was developed for water resources management under uncertainty. As a new extension of mathematical programming methods, the developed ITSSP approach has advantages in uncertainty reflection and policy analysis. In order to better account for uncertainties, the ITSSP approach is expressed with discrete intervals, functional intervals and probability density functions. The ITSSP method integrates the two-stage stochastic programming (TSP), interval programming (IP) and semi-infinite programming (SIP) within a general optimization framework. The ITSSP has an infinite number of constraints because it uses functional intervals with time (t) being an independent variable. The different t values within the range [0, 90] lead to different constraints. At same time, ITSSP also includes probability distribution information. The ITSSP method can incorporate pre-defined water resource management policies directly into its optimization process to analyze various policy scenarios having different economic penalties when the promised amounts are not delivered. The model is applied to a water resource management system with three users and four periods (corresponding to winter, spring, summer and fall, respectively). Solutions of the ITSSP model provide desired water allocation patterns, which maximize both the system’s benefits and feasibility. The results indicate that reasonable interval solutions were generated for objective function values and decision variables, thus a number of decision alternatives can be generated under different levels of stream flow. The obtained solutions are useful for decision makers to obtain insight regarding the tradeoffs between environmental, economic and system reliability criteria.     

Water Resources Management and Planning under Uncertainty: an Inexact Multistage Joint-Probabilistic Programming Method

In this study, an inexact multistage joint-probabilistic programming (IMJP) method is developed for tackling uncertainties presented as interval values and joint probabilities. IMJP improves upon the existing multistage programming and inexact optimization approaches, which can help examine the risk of violating joint-probabilistic constraints. Moreover, it can facilitate analyses of policy scenarios that are associated with economic penalties when the promised targets are violated within a multistage context. The developed method is applied to a case study of water-resources management within a multi-stream, multi-reservoir and multi-period context, where mixed integer linear programming (MILP) technique is introduced into the IMJP framework to facilitate dynamic analysis for decisions of surplus-flow diversion. The results indicate that reasonable solutions for continuous and binary variables have been generated. They can be used to help water resources managers to identify desired system designs against water shortage and for flood control, and to determine which of these designs can most efficiently accomplish optimizing the system objective under uncertainty.     

An Inexact Two-stage Fuzzy-stochastic Programming Model for Water Resources Management

An inexact two-stage fuzzy-stochastic programming (ITFSP) method is developed for water resources management under uncertainty. Fuzzy sets theory is introduced to represent various punishment policies under different water availability conditions. As an extension of conventional two-stage stochastic programming (TSP) method, two special characteristics of the proposed approach make it unique compared with existing approaches. One is it could handle flexible penalty rates, which are much reasonable for both of the authorities and users, and have seldom been considered in the TSP framework. The other is uncertain information expressed as discrete intervals and probability distribution functions can be effectively reflected in the optimization processes and solutions. After formulating the model, a hypothetical case is employed for demonstrating its applicability under two scenarios, where the inflow is divided into four and eight intervals, respectively. The results indicate that reasonable solutions have been obtained. They provide desired allocation patterns with maximized system benefit under two feasibility levels. The solutions present as stable intervals with different risk levels in violating the water demands, and can be used for generating decision alternatives. Comparisons of the solution from the ITFSP with that from the ITSP (inexact two-stage stochastic programming) and TSP approach are also undertaken. It shows that the ITFSP could produce more system benefit than existing methods and deal with flexible penalty policies for better water management and utilization.     

A Stochastic Non-linear Programming Model for a Multi-period Water Resource Allocation with Multiple Objectives

A rapid increase in demand and severe droughts in recent years has increased the pressure on water supplies throughout most parts of Australia. This has resulted in the need for tools to allocate limited water across users in different regions, and explore scenarios so as to achieve economic, social and environmental benefits. A major challenge in water resource allocation is dealing with the uncertainty in the system, particularly with respect to reservoir inflow. Stochastic non-linear programming is applied to water resource allocation to accommodate this uncertainty across the time periods of the planning horizon. A large range of solutions is produced representing the distributions of uncertainty in reservoir inflow. These solutions are used in a Monte Carlo simulation to estimate the trade-off in amounts of water allocated versus risk of not achieving minimal reservoir levels. The methodology is applied to a case study in South East Queensland in Australia, a region which is currently facing a severe water shortage over the next 3 years. A new water supply initiative that the Queensland State Government is considering to overcome the water crisis is assessed using the methodology.     

IFTSQP: An Inexact Optimization Model for Water Resources Management under Uncertainty

Abstract

An interval-fuzzy two-stage quadratic programming (IFTSQP) method is developed for water resources management under uncertainty. The methodincorporates techniques of interval-parameter programming, two-stage stochastic programming, and fuzzy quadratic programming within a general optimization framework to tackle multiple uncertainties presented as intervals, fuzzy sets and probability distributions. In the model formulation, multiple control variables are adopted to handle independent uncertainties in the model's right-hand sides; fuzzy quadratic terms are used in the objective function to minimize the variation in satisfaction degrees among the constraints. Moreover, the method can support the analysis of policy scenarios that are associated with economic penalties when the promised targets are violated. The developed method is then applied to a case study of water resources management planning. The results indicate that reasonable solutions have been obtained. They can help provide bases for identifying desired water-allocation plans with a maximized system benefit and a minimized constraint-violation risk.     

An Inexact Chance-constrained Quadratic Programming Model for Stream Water Quality Management

Water quality management is complicated with a variety of uncertainties and nonlinearities. This leads to difficulties in formulating and solving the resulting inexact nonlinear optimization problems. In this study, an inexact chance-constrained quadratic programming (ICCQP) model was developed for stream water quality management. A multi-segment stream water quality (MSWQ) simulation model was provided for establishing the relationship between environmental responses and pollution-control actions. The relationship was described by transformation matrices and vectors that could be used directly in a multi-point-source waste reduction (MWR) optimization model as water-quality constraints. The interval quadratic polynomials were employed to reflect the nonlinearities and uncertainties associated with wastewater treatment costs. Uncertainties associated with the water-quality parameters were projected into the transformation matrices and vectors through Monte Carlo simulation. Uncertainties derived from water quality standards were characterized as random variables with normal probability distributions. The proposed ICCQP model was applied to a water quality management problem in the Changsha section of the Xiangjiang River in China. The results demonstrated that the proposed optimization model could effectively communicate uncertainties into the optimization process, and generate inexact solutions containing a spectrum of wastewater treatment options. Decision alternatives could then be obtained by adjusting different combinations of the decision variables within their solution intervals. Solutions from the ICCQP model could be used to analyze tradeoffs between the wastewater treatment cost and system-failure risk due to inherent uncertainties. The results are valuable for supporting decision makers in seeking cost-effective water management strategies.     

A New Interval Two-stage Stochastic Programming with CVaR for Water Resources Management

Water Resources Management - In area of water resources management, decision-makers usually need to make plans under various uncertainties in order to achieve the maximal total net benefits and...     

Decision-making in Water Management under Uncertainty

Decision-making in water management requires the delivery of accurate scientific information. However, the task is challenging under the situation where a large amount of uncertainty exists in the available information (e.g., model outputs). This paper investigates the effect of uncertainty on the ranking of options in water management. Different methods for ranking the management options under uncertainty are reviewed and they account for only partial uncertainty information in model outputs. To consider the full uncertainty information, a new ranking procedure is proposed in this paper, which is capable of providing more information to decision makers and at the same time taking their opinions on uncertainty into consideration. The ranking is achieved by conducting pair-wise comparison of management options, on the basis of the risk defined by the probability of obtaining an unacceptable ranking and the mean difference in model outputs in pair-wise comparison. An application example is presented to illustrate the use of the proposed ranking approach. Furthermore, the sensitivity of management option ranking to different ranking methods and to model uncertainty is also investigated.     

Dual-Interval Two-Stage Optimization for Flood Management and Risk Analyses

In this study, a dual interval two-stage restricted-recourse programming (DITRP) method is developed for flood-diversion planning under uncertainty. Compared with other conventional methods, DITRP improves upon them by addressing system uncertainties with complex presentations and incorporating subjective information within its optimization framework. Uncertainties in DITRP can be represented as probability distributions and intervals. In addition, the dual-interval concept is presented when the available information is highly uncertain for boundaries of intervals. Moreover, decision makers’ attitudes towards system risk can be reflected using a restricted-resource measure by controlling the variability of the recourse cost. The method has been applied to a case study of flood management. The results indicate that reasonable solutions for planning flood management practice have been generated which are related to decisions of flood-diversion. Several policy scenarios are analyzed, assisting in gaining insight into the tradeoffs between risk and cost.     

A Comparison of Modelling Systems for the Development and Revision of Water Resources Management Plans

In this paper, two modelling systems used for the simulation of water resources management are compared. These modelling systems can be used in the implementation of the European Water Framework Directive or to perform any other kind of integrated assessment with regard to water resources management. In such investigations the use of models is inevitable, as integrated water resources management demands the survey of large areas as well as the inclusion of the different functions of the water cycle and water utilisation processes. Water quantity data provides important input for hydro-chemical, hydro-ecological or hydro-economic models. If no significant water resources management activities are realised in the basin under study, these data can be provided by simple rainfall-runoff models. If significant water resources management activities are realised or planned, the effects of these water resources management activities must be taken into consideration. Then, however, the use of water resources management models becomes necessary. Two such modelling systems, WRAP and WBalMo, are compared. Both have been designed for the development and revision of water resources management plans. Due to different approaches regarding the modelling routines the models lead to different results in the calculation of water quantities. By tracking the simulation algorithms, an understanding of the detected differences becomes possible. By adapting the spatial configuration of the modelled system, equivalent results can be obtained.     

Mathematical Modelling for the Integrated Management of Water Resources in Hydrological Basins

Mathematical models are tools that can facilitate the instrumentation of the Integrated Water Resources Management (IWRM). The first basin models to be developed were completely hydrological; today, due to the urgent need to plan the sustainable use of water resources, new models are needed that in addition to hydrology also incorporate social, economic, legal, environmental and other aspects. The objective of this work was to identify the characteristics that mathematical basin models must have in order to satisfy the requirements of IWRM. To achieve this, the conclusions of the main international conferences on water and the environment were analyzed; these were conferences in which IWRM was promoted as a strategy to face the challenges of both sectors. IWRM considers social participation as a key element in the decision-making process; consequently, the models must be accepted and applied, and their results interpreted, by those who participate in the process even if they are not modelling experts. This requires a change of perspective in the scientific community for the development of new IWRM models, in government institutions regarding their role as water administrators, and in water stakeholders regarding their role as decision-makers. The results of the analysis indicate that models for IWRM must be accessible to non-expert users, integrate different viewpoints, representing adequately the problem to be solved, in addition be flexible and have a structure focused on practical solutions.     

Water Resources Development and Management A Challenging Task for Botswana

Abstract

Since Botswana is part of drought prone region of Southern Africa due to its semi-arid climate, conservation and careful management of the water resources is a matter of necessity and great importance. Hence, the focus on water resources management and, in particular, integrated management has become critical over the past decade. This paper addresses the problem of water resources development with a particular reference to Botswana, which is a semi-desert region. The vagaries of climate, unpredictable, patchy rainfall, and even more erratic run-off events all make hydrological modeling difficult. High rates of evaporation and evapotranspiration losses present an additional challenge to water resources planners. Lack of good dam sites is another problem in Botswana's ancient, flat, and eroded landscape. This paper describes the present and future water demands of this country and a suggestion is made to improve the situation of water shortage. The Botswana National Master Plan has been developed to meet the challenge. The aim is to integrate the expanding water supply system of eastern Botswana, through a north-south carrier pipeline. A brief presentation and discussion of this system is given along with other challenges faced by the water resources planners, such as conjunctive use of the groundwater and surface water resources     

Management of Water Resources

Abstract

Recent reforms in water resources management in the Murray-Darling Basin are discussed from the perspective of water allocation, water rights, irrigation, and the environment, with particular reference to differences between details in the states of Victoria and New South Wales. A similar review of water resources management is made for Vietnam with some further discussion of the new water law of 1998. Contextual differences are discussed and the opportunities for Vietnam to make use of Australian experience are briefly analysed.     

Institutional Evolution in Lake Okeechobee Management in Florida: Characteristics,Impacts, and Limitations

The management of Lake Okeechobee in Florida has undergone significant changes in the last decade. Socio-political, environmental and demographic factors have driven changes in the environmental and water policy, which in turn have led to wide-ranging institutional changes and a shift toward multiobjective planning and implementation in the Lake management. This article describes the changes in the philosophy and practice of water resources management in South Florida hydrologic system, of which Lake Okeechobee is a crucial component. The impacts of the changes on management goals and decision processes are illustrated through a case study of the use of climate information in Lake management. The article concludes with a brief examination of the implications of the institutional changes, including greater public participation, for the long-term sustainability of the social-ecological system in South Florida.     

水资源管理系统区间数属性联系贴近度评价

针对水资源管理系统区间数多属性决策评价问题,借鉴集对分析理论,采用区间数属性联系贴近度评价方法,通过引进系统范数的概念进行属性区间数指标决策矩阵规范化处理,将区间数决策矩阵转化为联系数加权决策矩阵,获得水资源管理系统方案评价的计算方法,并通过实例对该方法的有效性和实用性进行验证,取得了较为满意的结果。     

加强水能资源管理促进农村水电建设

本文介绍了重庆市的水能资源开发和管理现状,就如何进一步加强水能资源开发和管理工作提出了建议。     

Water Resources Management Strategies for Adaptation to Climate-Induced Impacts in South Africa

This paper focuses on the development of a framework for strategy considerations for water resources management in South Africa to meet the development goals in the municipal and agricultural sectors. The north western part of South Africa experiences severe periods of drought and according to the climate change projections, will be most vulnerable to future climate induced water supply stress. A framework for selecting appropriate strategies is presented. A series of potential adaptation strategies most suitable for long term adaptation are discussed. These include both supply and demand side strategies. Barriers and obstacles to implementing these strategies include human and financial resource deficiencies at local municipal and community levels.     

The Use of System Dynamics Simulation in Water Resources Management

In this paper we discuss the use of system dynamics as a methodology with which to address dynamically complex problems in water resources management. Problems in regional planning and river basin management, urban water management, flooding and irrigation exhibit important short-term and long-term effects, and are often contentious issues with high potential for conflict. We argue that system dynamics combined with stakeholder involvement provides an appropriate methodology to address these issues effectively. We trace the theoretical and practical evolution of system dynamics in these areas over the past 50 years. From this review of the literature and selected case studies we identify and discuss a number of best practices and common pitfalls in applications of system dynamics simulation.     

Development of Data and Information Centre System to Improve Water Resources Management in Indonesia

Most provinces in Indonesia will be facing water scarcity problems in the next decades due to increasing water demands resulting from population growth, urbanization and economic and industrial developments. As a consequence, they will also be facing a number of problems with regards water resource management, such as a lack of data and information needed to evaluate the real status of water resources, the unsystematic development of relevant infrastructure and economic instruments, inadequate human resources for the operation and maintenance of water resources, and a lack of interest in improving research and development activities. This paper examines the application of data and information management for improved water resources management in Indonesia through “one door data service system” linked among the related institutions from different sectors and levels both at the central and regional government agencies. One of the key solutions to help solve water resource problems would therefore be to obtain supporting data and information by developing an information system and water resources data centre (WRDC). Rapid developments in information and communication technology (ICT) could be used to support data communication and management requests in order to build capacity of the water resources sector, and as a prerequisite for an integrated water resources management program. Improved efficiency and effectiveness could be achieved by making relevant data and information available, as well by establishing a communication system among related institutions. Further, provinces should also prioritize developing human and social capital through education, service delivery and career development, as well as training for water resources development and management. Data and information such as the hydrological and water quality data, information of water resources potential, irrigation areas, population and economic growth as well as the others related data need to store in both the tabular and spatial formats. The water resources data management and warehouse system is a web-enabled application that permits spatial data to be stored with tabular data in a standard database management system. This system permits a dynamic generation of output from the tabular and spatial data and enables users to generate answers to their queries online, rather than simply presenting static maps and tables from the database. The WRDC applications were developed and chosen by gathering the ideas suggested by users at the ministerial, provincial and river basin levels. Within the resulting inventory system, information was grouped into irrigation scheme system; water resources potential; natural disaster; hydrological data and station networks; and other information. For the users at the ministerial level access the system by using local area network (LAN) connections and other users at the provincial and river basin levels or elsewhere in the world can use the internet for connections and regular browser software for system operation.     

A Decision Support System to Improve Water Resources Management in the Conchos Basin

The Conchos basin is the largest tributary to the lower part of the Rio Grande/Rio Bravo basin. During recent years a severe drought has affected México’s ability to deliver water from the Conchos basin as required by the 1944 Treaty. In addition, it has generated not only economic problems in the USA and México but also political frictions between these two countries. The Mexican Conchos river has historically contributed with the highest amount of water to USA as established on the water treaty. A Decision Support System (DSS) was developed for the Conchos basin in order to gain a better understanding of the water resources management process in the basin, and to identify the alternatives to improve the cited process. The DSS is a semi-distributed model, based on System Dynamics, and developed using Powersim software. The DSS has been used to evaluate 25 long and short tem water resources allocation alternatives for the two main basin’s users: Irrigation Districts and Water Treaty. Some of the most important factors being tested on the 25 water management alternatives include National Commission of Water’s yearly water allocation policy, reservoir operation rules, improvement on water distribution efficiencies, etc. The DSS model shows that the historic water resources allocation implemented by the Federal government produces adequate results as compared with the other tested water management alternatives. However, for short term drought scenarios, it is showed that there could be other management alternatives that could perform better than the current water management allocation. In general, the DSS shows what we already expect of dynamic models of systems to provide that understanding the effects of multiple interacting variables in necessary to develop good natural resource management policies.