A Model for Optimal Allocation of Water to Competing Demands

The present study develops a simple interactive integrated water allocation model (IWAM), which can assist the planners and decision makers in optimal allocation of limited water from a storage reservoir to different user sectors, considering socio-economic, environmental and technical aspects. IWAM comprises three modules—a reservoir operation module (ROM), an economic analysis module (EAM) and a water allocation module (WAM). The model can optimize the water allocation with any of two different objectives or two objectives together. The two individual objectives included in the model are the maximization of satisfaction and the maximization of net economic benefit by the demand sectors. Weighting technique (WT) or simultaneous compromise constraint (SICCON) technique is used to convert the multi-objective decision-making problem into a single objective function. The single objective functions are optimized using linear programming. The model applicability is demonstrated for various cases with a hypothetical example.     

寺坪水电站优化调度模型

随着社会经济的快速发展,水资源供需矛盾日趋尖锐,如何合理调度有限的水资源已成为水资源管理中的现实而紧迫的任务。通过进一步研究水库调度的机理,采用非线性规划作为优化求解方法构建了水库优化调度模型,非线性规划结合了线性规划和动态规划各自的优点,并将水库调度中的各种因素融入数学模型中,较准确地计算模拟期间各种优化变量数值条件下的目标函数值,并比较得出最优值。之后,基于多目标思想,给出了一组Pareto前沿解集,通过寺坪水电站的应用,构建不同的目标函数,得到一系列决策方案,以便决策者选择偏好的决策方案。     

基于二元水循环及系统熵理论的城市用水配置

基于二元水循环理论,在分析城市水资源配置系统结构基础上,构建了考虑水资源质、量均衡的城市用水优化配置模型,并运用多目标求解方法获得水资源分配的可行方案;对信息熵进行改进,构建了系统熵,并将其应用于可行方案的评价中。对昆明市水资源的优化配置计算结果表明,当重视生态效益或者综合考虑生产、生活、环境及生态效益时,系统熵值较小,这将有利于水资源系统的长期健康运行;该方法不仅能对城市用水系统进行简洁有效的分析评价,亦能对用水系统的结构调整、系统发展提供参考意见。     

流域水资源规划的系统观与方法论

本文系统地阐述了在市场经济条件下, 水资源总体规划体系应建立以流域系统为对象、以流域水循环为科学基础、以合理的配置为中心的系统观, 以多层次、多目标、群决策方法作为流域水资源规划的方法论. 另外在规划方案具体设置当中, 要兼顾可能和需要两方面因素.     

Operating Rules of an Irrigation Purposes Reservoir Using Multi-Objective Optimization

A multi-objective optimization technique for the operation of an irrigation reservoir is presented in this paper. The study deals with two different objective functions (OF): the minimization of reservoir release deficit from the irrigation demand (OF1) and the maximization of net benefit by the demand sector (OF2). In the first step, monthly optimization of each individual objective was performed with a deterministic non-linear programming (NLP) algorithm, that gave the lower and upper bounds for the multi-objective analysis. In the second step, multi-objective optimization was performed through the Constraint method that operates by optimising the objective function OF1, while the other (OF2) was constrained to satisfy release strategies generated by the optimization. Non-dominated set of release strategies is generated by parametrically varying the bounds of the constraints obtained from the individual optimal solutions. In the third step, the interactive analytical Step method was applied to find the best compromise solution, between the two OFs, by minimizing the distance of each non-dominated solution to an ideal solution that represents the utopian optimum for both OF1 and OF2. Furthermore, the interactive approach allows to improve the performance of the reservoir in terms of compromise irrigation releases, by changing the OF values until the satisfaction of predetermined criteria fixed by the planners and decision makers. The proposed water allocation model was applied to the Pozzillo reservoir operation, that supplies the Catania Plain irrigation area (Eastern Sicily).     

Editorial Comments on the World Commission on Water for the 21stCentury

Abstract

In this study, in order to create a decision-making model on water resources projects, a hierarchy of criteria has been developed by public participation. The Value Management methodology has been used for extraction of the effective criteria and attributes in the scope of Integrated Water Resources Management (IWRM). The hierarchy is generic for water resources management in the Islamic Republic of Iran. Since the evaluations of alternatives with respect to some attributes are uncertain and vague, fuzzy set theory has been used. By merging fuzzy set theory and multi-attribute decision-making a new Decision Support System (DSS), namely FDM, has been developed to compare different alternatives. As an innovation, FDM accepts evaluations of alternatives with respect to the attributes as crisp variables, fuzzy variables, and linguistic variables. FDM embodies an expert system whose duty is to choose an appropriate method among the SAW, Fuzzy SAW, TOPSIS or Fuzzy TOPSIS based on the characteristics of the problem.

The central and Southeastern regions of Iran are considered arid regions, suffering from water shortages. In this paper, water transfers to the Zayanderud basin in Iran have been modeled by FDM. Successful application of this DSS in this study allows for its application by water authorities in other case studies.     

Bi-objective analysis of waste load allocation using fuzzy linear programming

Because of its complexity from both a legal and economic standpoint, the problem of optimal waste load allocation is multiobjective by nature and should be treated accordingly. To perform this task, an optimization technique known as fuzzy linear programming is utilized in solving a multiple-discharge, two-objective waste load allocation problem. The two objectives considered are: (1) the maximization of waste discharge and (2) the minimization of the largest difference in equity measure between the various dischargers. Results from this study reveal that fuzzy linear programming is a valuable tool for solving the multiple-objective water quality management problems. Moreover, it is shown that the selection of a linear or logistic membership function in providing preference criteria between the two objects, has no effect on the best compromising solution.     

水电规划环境影响评价替下七方案优选研究

针对水电开发规划环境影响评价,将多目标规划理论引入水电规划替代方案筛选研究,构建了基于景观多样性变化率、淹没土地面积、移民数量等环境约束的多目标替代方案优选模型,引入灰色关联系数作为粒子群算法的适应值函数,提出了多目标粒子群求解算法.通过模型应用,得到黄河黑山峡河段水电规划多个相对优化方案.模型应用及求解表明,多目标规划理论用干替代方案优化,突破了以往单方案或两个方案评价的片面性.     

基于鲁棒规划方法的农业水资源多目标优化配置模型

在干旱半干旱地区,调整种植结构可以促进农业水资源的高效利用。农业水资源配置需要在多个目标间权衡博弈,对各目标的偏好和赋权直接影响着优化模型的输出和决策方案的制定,但以往研究往往忽略了权重确定过程中因主观等因素的影响而普遍存在的不确定性。针对农业水资源多目标规划中存在的权重不确定性难题,建立了基于鲁棒优化方法的农业水资源多目标优化配置模型方法(MRPWU)。该方法可以把权重中蕴含的复杂不确定性信息纳入建模过程,产生可靠的模型结果;并能提供效益值及风险值均定量化的方案集,便于决策者在权衡效益与风险后确定最优方案。模型以作物种植经济收益和碳吸收量最大化为目标、以水土资源供需平衡等为约束条件,并应用于农业水资源供需矛盾突出的甘肃省民勤县。优化结果表明,随着保护度水平的提高,生态效益上升,经济效益和综合效益下降,系统面临的风险也随之下降。相比于权重为确定参数的模型,MRPWU模型可以在综合效益下降3.7%的同时,较大地提高系统应对权重不确定性以及风险的能力。与2017年的实际情况相比,MRPWU模型可以减少种植面积1.6%、节省灌溉用水3.9%,同时提高生态效益1.6%。     

干旱期水库供水特征及运行性能分析

 阐述了目前较常用的干旱期水库运行性能特征体系的主要表征指标，并给出了可操作的实用性计算表达式；建立了基于供水可靠性最大、供水破坏恢复能力最强以及单一时段破坏深度最小的多目标混合整数规划模型，对模型结构进行了具体描述；在实例应用研究中，运用权重法处理多目标问题，并通过分析多种目标权重组合对模型运算结果的影响，论述了2种多目标函数形式的决策过程特征，比较了2种多目标函   数在干旱期水库运行性能评价应用方面的优缺点。