Multi-criteria Decision Making for Integrated Urban Water Management

The city of Zahedan, in South-eastern Iran, has high population growth, limited local freshwater resources and inadequate water distribution system resulting in water supply failures in recent years. This paper will investigate integration of several demand management measures such as leakage detection on water distribution network, water metering and low volume water fixtures as well as the conjunctive use of surface and groundwater resources of this city. For integration of water management criteria, compromise programming will be used as a multi-objective decision making method. The criteria include minimizing the cost, maximizing water supply and minimizing the social hazards due to the water supply operations. This model will derive optimum long-term plans for implementation of water resources. The results will show that demand management can delay a water transfer project for Zahedan city up to 10 years. Compromise programming is as an efficient tool for integrated water resources management in urban areas and the method is capable to being used by decision-makers in other cases.     

Managing Water Supply and Demand to Achieve Economic and Environmental Objectives: Application of Mathematical Programming and ANFIS Models

The integrated management of water supply and demand has been considered by many policymakers; due to its complexity the decision makers have faced many challenges so far. In this study, we proposed an efficient framework for managing water supply and demand in line with the economic and environmental objectives of the basin. To design this framework, a combination of ANFIS and multi-objective augmented ε-constraint programming models and TOPSIS were used. First, using hydrological data from 2001 to 2017, the rate of water release from the dam reservoir was estimated with the ANFIS model; afterwards, its allocation to agricultural areas was performed by combining multi-objective augmented ε-constraint models and TOPSIS. To prove the reliability of the proposed model, the southern Karkheh basin in Khuzestan province, Iran, was considered as a case study. The results have showed that this model is able to reduce irrigation water consumption and to improve its economic productivity in the basin.

     

Consideration of Trends in Evaluating Inter-basin Water Transfer Alternatives within a Fuzzy Decision Making Framework

Evaluation of water supply schemes is an essential task for meeting the goals of inter-basin water transfer project system management. In general, water supply operation involves multi-objective and multifactor optimization and decision. In recent years, multicriterion decision making (MCDM) has emerged as an effective methodology due to its ability to combine quantitative and qualitative criteria for selection of the best alternative. This paper presents a new optimization method using fuzzy pattern recognition to appraise the water supply decision schemes in inter-basin diversion systems. The proposed method is capable to incorporate not only the will of the decision-makers but also the future development trend of water resources and water supply demand and makes the optimization results more reasonable and applicable. One case study for the Xi-River-to -Tanghe Reservoir Water Transfer Project System in China is presented to demonstrate the application of this method.     

A Multi-objective Linear Programming Model with Interval Parameters for Water Resources Allocation in Dalian City

Water resources management has been of concern for many researchers since the contradiction between increased water demand and decreased water supply has become obvious. In the real world, water resources systems usually have complexities among social, economic, natural resources and environmental aspects, which leads to multi-objective problems with significant uncertainties in system parameters, objectives, and their interactions. In this paper, a multi-objective linear programming model with interval parameters has been developed wherein an interactive compromising algorithm has been introduced. Through interactive compromising conflicts among multi-objectives, a feasible solution vector can be obtained. The developed model is then applied to allocation of multi-source water resources with different water qualities to multiple users with different water quality requirements for the Dalian city for 2010, 2015 and 2020 planning years. The model pursues the maximum synthesis benefits of economy, society and the environment. The results indicate that the proportion of reused water to the total water amount is gradually increasing, and the proportion of agricultural water consumption to the total water consumption is gradually decreasing. The allocation of multi-source water resources to multiple users is improved due to incorporation of uncertain factors into the model that provide useful decision support to water management authorities.     

Integrated Water Resources Management in Polrud Irrigation System

Water is needed in all aspects of life and is vital to its social, economical and environmental dimensions. Having a key role in sustainable development, water management requires an integrated approach. Irrigation Water shortage promotes the development of innovative management and supply enhancement models. Effective water management requires a comprehensive consideration of all related aspects, e.g., technical, social, environmental, institutional, political and financial. Then the conventional methods of cost-benefit analysis and single-objective models have changed to multi-objective models. The rising of population in Iran puts significant pressure on authorities and infrastructures to provide water. Without improvement in water management, Irrigation demand will continue to increase, water supplies will diminish and the population pressure will decay infrastructure. This paper describes compromise programming to solve multi-criteria decision making in irrigation planning for Polrud project in the North of Iran. The important objectives of project are: regulation of reliable water at the demand time, improving rice and tea production, domestic water supply, environmental needs as well as reducing social conflicts. After execution of the model, results show the optimum decision for crops pattern and extents of allocated water to each area. This study is a successful implementation of IWRM in irrigation planning.     

A Negotiation-Based Multi-Objective, Multi-Party Decision-Making Model for Inter-Basin Water Transfer Scheme Optimization

The planning and management decisions often involve multiple objectives and multiple parties with conflicting interests due to the complexity of inter-basin water transfer systems. In this paper, the objectives, the groups involved and the corresponding conflicting interests that characterize water transfer decisions are analyzed. A multi-party, multi-objective decision/bargaining model based on the ??satisfaction principle?? is developed for inter-basin water transfer system decision-making. In order to obtain an ideal multi-party decision, bargaining is first broken down into two stages, and then decision alternatives are chosen using fuzzy pattern recognition. This model is simple, and it is more adaptable for solving practical multi-objective and multi-party decision problems. Finally, an inter-basin water transfer scheme optimization example is demonstrated by using the developed model.     

Multi-Objective Surface Water Resource Management Considering Conflict Resolution and Utility Function Optimization

In the present research, a multi-objective model is developed for surface water resource management in the river basin area which is connected to the lake. This model considers different components of sustainable water resource management including economic, social and environmental aspects, and simultaneously tries to resolve conflicts between different stakeholders by means of non-symmetric Nash bargaining, which is linked to the multi-objective optimization method. This study proposes a new methodology to improve Nash Conflict Resolution through finding the optimum degree of the utility function. The proposed model is examined in the Zarrineh River basin in Iran. The results show that the amount of available resources or volume of reservoirs play a significant role in determining the optimal degree of the utility function and efficiency of the proposed method in such a way that the higher amount of resources or the larger reservoirs will result in the higher optimal degree of the utility function. In the proposed multi-objective model, two different amounts of surface water inflow are considered. The first assumed amount is the long-term average flow rate and the second one is equal to 80% of the first mode, which is reduced based on the estimated impacts of climate changes. This multi-objective allocation model could supply 100 and 97.5% of the environmental demand of Lake Urmia in the first and second situations, respectively.     

多目标约束下区域水资源优化配置研究

随着社会经济的快速发展,用水需求增加与水资源短缺、水资源污染之间的矛盾日益尖锐,使得水资源已经成为制约区域社会经济发展的瓶颈。文章在综合考虑经济、社会、生态等因素的基础上,建立区域多目标水资源优化配置模型,实现从传统的单目标约束向多目标约束转变的新研究思路。在多目标约束下以济宁市为研究对象,通过建立模型和对优化配置结果的分析,诊断出济宁市农业和工业存在严重缺水情况,超过全市平均缺水率的城市有市中区、任城区、曲阜市、邹城市、泗水县和嘉祥县。研究结论将为区域水资源优化配置、落实最严格水资源管理制度提供决策依据。     

Simulation and Multi-Objective Management of Coastal Aquifers in Semi-Arid Regions

Groundwater is the main water resource in many semi-arid coastal regions and water demand, especially in summer months, can be very high. Groundwater withdrawal for meeting this demand often causes seawater intrusion and degradation of water quality of coastal aquifers. In order to satisfy demand, a combined management plan is proposed and is under consideration for the island of Santorini. The plan involves: (1) desalinization (if needed) of pumped water to a potable level using reverse osmosis and (2) injection into the aquifer of biologically-treated waste water. The management plan is formulated in a multi-objective, optimization framework, where simultaneous minimization of economic and environmental costs is desired, subject to a constraint so that cleaned water satisfies demand. The decision variables concern the well locations and the corresponding pumping and recharging rates. The problem is solved using a computationally efficient, multi-objective, genetic algorithm (NSGAII). The constrained multi-objective, optimization problem is transformed to an unconstrained one using a penalty function proportional to constraint violation. This extends the definition of the objective function outside the domain of feasibility. The impact of prolonged droughts on coastal aquifers is investigated by assuming various scenarios of reduced groundwater recharge. Water flow and quality in the coastal aquifer is simulated using a three-dimensional, variable density, finite difference model (SEAWAT). The method is initially applied to a test aquifer and the trade-off curves (Pareto fronts) are determinedl for each drought scenario. The trade-off curves indicate an increase on the economic and environmental cost as groundwater recharge reduces due to climate change.     

基于可持续发展的区域水资源优化配置研究

运用可持续发展的水资源优化配置理论,以区域经济发展与水环境保护相协调为目标,建立地下水开采漏斗区水资源多目标优化配置模型。采用多目标遗传算法对漏斗区水资源进行合理配置。优化配置结果表明:基本解决了漏斗区供需矛盾,缓解了地下水的开采压力。     

改进的风险决策及NSGA-Ⅱ方法在马莲河流域水资源综合管理中的应用

将马莲河流域系统概化为5个水资源分区,采用指标分析法进行2020和2030年供需水量预测和平衡分析。利用改进的决策树法进行风险分析,将专家咨询概率法引入到决策树敏感性分析中,最终得到2020、2030年的推荐水资源供需分配方案。然后,利用系统分析理论和优化技术建立了流域的大系统、多目标水资源优化配置模型,并采用优化的NSGA-Ⅱ方法进行求解,得到流域2030年推荐水资源配置方案下的最佳分配方案。最后,根据最佳分配方案和预测的流域需水量,进行了流域的水资源平衡分析,通过平衡分析的结果进行流域的综合管理研究。最佳配置方案实现了流域内水资源的最优分配,使宝贵、有限的水资源产生最大的社会、经济及环境效益,为流域经济、能源产业的快速发展提供水资源保障。     

Multi-criteria Decision Analysis: A Strategic Planning Tool for Water Loss Management

Water utilities particularly in the developing countries continue to operate with considerable inefficiencies in terms of water and revenue losses. With increasing water demand and scarcity, utilities require effective strategies for optimum use of available water resources. Diverse water loss reduction options exist. Deciding on which option to choose amidst conflicting multiple criteria and different interests of stakeholders is a challenging task. In this paper, an integrated multi-criteria decision-aiding framework for strategic planning of water loss management is presented. The PROMETHEE II method was applied within the framework in prioritizing water loss reduction options for Kampala city. A strategic plan that combines selective mains and service lines replacement and pressure management as priorities is the best compromise based on preferences of the decision makers and seven evaluation criteria characterized by financial-economic, environmental, public health, technical and social impacts. The results show that the most preferred options are those that enhance water supply reliability, public health and water conservation measures. This study demonstrates how decision theory coupled with operational research techniques could be applied in practice to solve complex water management and planning problems.     

面向发电、供水、生态要求的赣江流域水库群优化调度研究

以赣江流域内已建成的大型控制性水库为研究对象,将赣江流域上游至下游用水区概化成7个主要用水区域,综合考虑各水库的运用目标、流域主要用水区域水量需求以及河道内生态流量的要求,以水库群总发电量最大、用水区域总缺水量最小和外洲控制站调度后流量与天然流量偏差最小为目标,建立面向发电、供水、生态要求的赣江流域水库群优化调度模型,采用多目标粒子群算法进行求解,得到不同来水频率下发电、供水和生态3个目标的非劣解集,并对3个目标之间的竞争关系进行了剖析。最后分析了各典型方案相应的水库水位过程和区域缺水情况。结果表明:各来水频率下,发电、供水、生态3个目标之间竞争程度有强有弱,其中发电目标与生态目标之间、供水目标与生态目标之间存在较强的竞争性,发电目标与供水目标之间则相对较弱。     

Sustainable Water Supply and Demand Management in Semi-arid Regions: Optimizing Water Resources Allocation Based on RCPs Scenarios

Climate as one of the key factors in water resources management affects the amount of water in the hydrological cycle, which subsequently impacts the level of water availability. Considering the challenges that the South Alborz Region, Iran is currently facing in supplying water for various consumers; in this study, the climate change adaptation scenarios are investigated for sustainable water supply and demand. This study uses a procedure in which five different adaptation approaches, under RCPs scenarios, were established using the WEAP model to assess the impacts of various adaptation strategies on increasing the balance between water supply and demand over current and 2020s accounts. The findings suggest an imbalance between supply and demand in the current situation with the greatest imbalance in domestic use while the minimum in the industrial sector. The results of assessing adaptive scenarios show that various scenarios have different effects on balancing the water supply and demand by different consumers; on the other hand, the scenarios that directly affect domestic water demand have the greatest effect on minimizing the gap between supply and demand in the region; therefore, the options for decreasing the population demand along with diminishing the losses in the domestic water distribution network are the most effective alternatives for balancing supply and demand under all of the climate scenarios. The findings of this research indicate that adaptive management with the focus on restricting demand helps actively management of water resources in the regions with scarce water resources.

     

西辽河平原区水资源供需平衡分析

西辽河平原区河道沙化现象日益突出,引发了一系列的生态环境问题,水资源匮乏是河道沙化的主要原因。利用MIKE BASIN软件,建立了西辽河平原区水资源管理规划模型,根据平原区水循环的特点,在流域关键节点径流量、供水量及水资源蓄变量3个方面对模型进行了验证,结果令人满意。利用建立的模型,基于3次平衡理论对研究区2020水平年水资源供需状况进行了分析。结果表明:西辽河平原区缺水程度为24.7%,属资源性缺水,强化节水及跨流域调水是解决本区水资源供需矛盾的有效措施。采取强化节水措施后,减少需水占一次平衡缺水的63.6%,引绰济辽跨流域调水工程实施后,受水区水资源短缺问题得以缓解,通辽市科尔沁区地下水位有望每年回升0.16 m。     

Scenario Optimisation of Pumping Schedules in a Complex Water Supply System Considering a Cost–Risk Balancing Approach

The optimisation of water pumping plant activation schedules is a significant issue when managing emergency and costly water transfer under a drought risk. This problem needs specific optimisation tools to deal with complex multi-reservoir supply systems and to consider different alternative scenarios. The effectiveness of emergency transfers alleviating droughts requires early warning and activation; on the other hand, the high operating costs of pump stations require system managers to take a robust approach that defines activation rules. The proposed optimisation procedure combines scenario optimisation analysis with a cost-risk balancing approach. The model searches for the identification of optimal decision rules by balancing the risk of water shortages and the operating costs of pumping stations. Scenario optimisation provides ‘barycentric’ values that define the activation threshold by comparing hydrological synthetic series results. A multi-objective approach is also required in order to balance energy cost minimisation requirements and a reduction of damage needs that can be caused by water shortages. Consequently, a scenario optimisation has been developed considering the multi-objective and cost-risk balancing problem. A model application has been developed optimising water management and energy costs in a real water system with shortage risks in the South Sardinia (Italy) region.     

基于MDIP-VIKOR的水库多目标调度方案评价模型

针对水库多目标调度方案优选问题,构建了MDIP-VIKOR评价模型。模型有机地耦合了主客观权重优化技术和VIKOR模型,一方面运用最小鉴别信息原理提高了指标权重的可信度,另一方面运用最大化群体效益和最小化个体损失的评价原理进行评价决策,增强了决策过程的合理性。实例应用结果表明:所建模型有效融合了主客观权重信息,所选出的调度方案追求的是在不降低原防洪标准前提下提高梯级水库的综合效益,具备更高的合理性和更强的执行性,可为水库多目标调度决策提供一种新途径。     

基于多目标不确定性机会约束规划的矿区水资源配置研究

以矿区水资源配置系统为研究对象,针对矿区生态恢复过程水资源配置的多目标、模糊、不确定性的特点,构建多目标不确定性机会约束规划模型对矿区水资源进行优化配置。基于生态优先的配水原则,以碳排放最小化目标代替传统的污染物排放量最小化目标,兼顾碳排放最小化、系统经济效益最大化以及缺水量最小化,建立矿区生态环境-经济社会-水资源协调发展的多目标模型,统筹分配地下水、地表水、矿井水以及再生水。对实际情况中的不确定性因素采用区间参数的方法表示,并通过遗传算法对模型进行求解,得到合理的水资源配置方案。将模型应用于宁夏回族自治区羊场湾矿区,结果表明：以碳排放为目标的不确定性机会约束规划多目标模型能够很好地统筹矿区经济发展目标与水资源节约目标,配置方案可保证各个用水部门的需水满足度达到100%,而以污染物排放量为目标的优化方案存在区域缺水的情况。系统可带来年碳净吸收量(CO₂)为533.7～702.4 t,预期年经济效益为162.3×10⁴～163.7×10⁴元,区域年供水富余量为43.5×10⁴～49.7×10     

基于改进SD的区域水土资源联合配置研究

将区域水土资源联合配置的多学科综合与新技术的应用成果相结合,以水土资源联合配置的体系为基础,定量刻化了水资源、土地资源配置系统与社会、经济、环境发展之间的互动影响关系,将包括需水、供水、土地需求及供给和生态环境影响等相关的水资源、土地资源联合配置的要素,与社会、经济、环境系统耦合成一个复杂的水资源-土地资源-社会经济-生态模拟系统,利用基于图论改进的流率基本入树的系统动力学(SD)规范建模方法,建立起了比较完整的区域水土资源优化配置的系统动力学流率基本入树模型。运用该模型,对位于苏南丘陵地区的句容市按照不同水土资源联合配置方案(情景)的水资源、土地资源与社会经济环境耦合系统进行模拟计算,该计算结果可为水资源、土地资源的联合统一管理提供基础支撑。     

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%。