The Application of a Water Rights Trading Model Based on two-Stage Interval-Parameter Stochastic Programming

In recent decades, increasing conflicts have occurred between different water users because of issues related to water resource allocation. To better allocate water resources, this study adopts the latest water rights trading model instead of the traditional water resources allocation model and combines it with a two-stage interval-parameter stochastic programming model (TISP). The combined model was applied to the Sanjiang Plain with multi-area, multi-source, and multi-water users, and the optimized promised water availability for every user in the area was obtained. The analysis shows that a higher promised water availability corresponds to a higher benefit but also promotes additional risks because of water shortages, whereas a lower promised water availability corresponds to a lower benefit, although it is more likely to result in water waste at high inflow levels. The combined model formed an effective link between water use benefits and water deficiency punishments that enabled us to obtain an optimized promised water availability that considers benefits and risks simultaneously. The second result is that the water rights trading model can improve the utilization efficiency of water resources, which are typically transferred from inefficient water use areas to efficient water use areas, resulting in a benefit to all areas. Additionally, in the water rights trading model, self-profit motivation at a micro-level can emerge in adaptation at a macro-level, which stabilizes the water resource system and reduces the possibility of system collapse because of extreme water shortages.     

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.     

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.     

漳卫南灌区农业水资源优化配置研究

考虑到不确定条件下漳卫南灌区农业水资源管理的复杂性,为了解决当灌区水资源用户供水目标不能满足需求时的水资源优化配置问题,结合LFP模型与TSP模型的优点,开发了一种分式两阶段随机规划模型(FTSP)。选择漳卫南灌区最大控制性工程岳城水库的两个大型供水灌区作为验证实例,模型应用结果表明,不同决策情景所对应的经济效益和缺水风险不同,最优决策实现了经济效益和缺水风险之间的平衡;不同径流水平下,各用户的正常灌溉面积会发生相应变化,高径流水平时所有用户均能得到正常灌溉。     

Interval-parameter Two-stage Stochastic Nonlinear Programming for Water Resources Management under Uncertainty

Over the past decades, controversial and conflict-laden water allocation issues among competing interests have raised increasing concerns. In this research, an interval-parameter two-stage stochastic nonlinear programming (ITNP) method is developed for supporting decisions of water-resources allocation within a multi-reservoir system. The ITNP can handle uncertainties expressed as both probability distributions and discrete intervals. It can also be used for analyzing various policy scenarios that are associated with different levels of economic consequences when the promised allocation targets are violated. Moreover, it can deal with nonlinearities in the objective function such that the economies-of-scale effects in the stochastic program can be quantified. The proposed method is applied to a case study of water-resources allocation within a multi-user, multi-region and multi-reservoir context for demonstrating its applicability. The results indicate that reasonable solutions have been generated, which present as combined interval and distributional information. They provide desired water allocation plans with a maximized economic benefit and a minimized system-disruption risk. The results also demonstrate that a proper policy for water allocation can help not only mitigate the penalty due to insufficient supply but also reduce the waste of water resources.     

玛纳斯河流域山前平原区地下水系统模型研究

新疆干旱少雨，冰川融水季节性较强，要满足工、农业的快速、持续发展，需合理有效地开采、利用地下水资源。玛纳斯河流域周边地区经济发展较快，以灌溉为主的农业生产及工业发展更离不开水资源的供给。本文分析了玛纳斯河流域平原区地下水资源赋存特点，依据开采区含水层水文地质特征，在对研究区边界及初始条件进行合理概化基础上建立了地下水系统模拟模型。考虑到地下水资源动态变化受人工开采型、水文-人工开采型、气候型等混合形式影响的特点，将水资源补给、排泄项划分到7个时段，研究区划分为620个单元和339个结点，采用有限元方法对模型进行数值离散，在边界条件及垂向水交换量进行动态模拟基础上对潜水和承压水非稳定流动态流场进行了拟合，拟合结果中误差小于0．5m的结点数超过总结点数的85％。得到了该区地下水系统水文地质参数，实现了地下水开采较大的冲洪积扇区较高精度的水资源动态模拟，同时为水资源变化预报预测提供了可靠参数及模型基础。     

水权分置与流域和谐发展

流域作为一种区域概念,它的经济、社会、环境协调发展对于建设社会主义和谐社会具有重要意义。从水资源产权的概念和内涵出发,分析了对流域水资源产权进行初次和二次分置的措施、方式和意义,并在此基础上给出政策意见:要促进流域上下游、左右岸、干支流的和谐发展,必须健全和完善流域管理体制,培育水权二次转让市场,利用政府和市场的协同力量实现水资源分配公平和效率的统一。     

Planning for Regional Water System Sustainability Through Water Resources Security Assessment Under Uncertainties

A leader-follower relationship in multiple layers of decision makers under uncertainties is a critical challenge associated with water resources security (WRS). To address this problem, a credibility-based chance-constrained hierarchical programming model with WRS assessment is developed for regional water system sustainability planning. This model can deal with the sequential decision-making problem with different goals and preferences, and reflect uncertainties presented as fuzzy sets. The effectiveness of the developed model is demonstrated through a real-world water resources management system in Beijing, China. A leader-follower interactive solution algorithm based on satisfactory degree is utilized to improve computational efficiency. Results show the that: (a) surface water, groundwater, recycled water, and off water would account for 27.01, 27.44, 23.11, and 22.44% of the total water supplies, respectively; (b) the entire pollutant emissions and economic benefits would consequently decrease by 31.53 and 22.88% when the statue changes from quite safe to extremely far from safe; and (c) a high credibility level would correspond to low risks of insufficient water supply and overloaded pollutant emissions, which lowers economic benefits and pollutant emissions. By contrast, a low credibility level would decrease the limitations of constraints, which leads to high economic benefits and pollutant emissions, but system risk would be increased. These findings can aid different decision makers in identifying the desired strategies for regional water resources management under multiple uncertainties, and support the in-depth analysis of the interrelationships among water security, system efficiency, and credibility level.     

Risk Assessment for Ecological Planning of Arid Inland River Basins Under Hydrological and Management Uncertainties

The Shiyanghe river basin, an arid inland basin of northwest China, is taken as an example to analyze the risk for achieving the ecological planning objective in arid inland river basins under uncertainty conditions. Hydrology and management uncertainties that affect the accomplishment of ecological planning objective are analyzed quantitatively with the methods of Bayesian theory based Probabilistic model, scenario analysis and interval analysis. Bayesian probabilistic analysis method was used to analyze the hydrological uncertainties in the form of probability and interval distributions in planning period, while the scenario analysis method and interval method were used to analyze the managing uncertainties in the form of interval numbers. Instead of the ecological risk analysis, which for arid inland river basin, of studying the impact of environmental and human factor on ecological system, water resources and environment, we focused on analysing the possible impact of hydrological and management uncertainty factor on the ecological planning, and forecasting the degree of the completion under the uncertainty. Our study provided the probabilities of achieving ecological planning objective and the possible deviation of different scenarios. The more local water resources and higher level of local water resource utilization and management appeared to lead higher probability to achieve the ecological objective. This study can help environment and water resource managers and planner to formulate a rational planning for arid inland river basins under hydrological and management uncertainty.     

基于最严格水资源管理制度的水资源利用考核关键技术研究——以南水北调东线江苏省受水区为例

针对技术与管理层面对最严格水资源管理制度量化实施支撑不足的问题,为满足跨流域调水复杂水工程集群的管理需求,以南水北调江苏受水区为研究对象,从水资源高效利用角度出发,基于课题组建立的多层次水资源模拟与配置模型,核定并解析地级市、水资源分区、区段、梯级等多层次区域用水总量控制目标,基于现状用水与高效用水不同模式,进行用水总量考核;构建水资源利用效率指标体系,评估水资源利用效率。结果表明:水资源利用总量控制考核全体达标;水资源利用效率方面,北高南低,差距较大,其中最高综合得分1. 2,最低-5. 1;研究区节水潜力有待进一步深入挖掘,尤其是在水源相对充足的区域,水资源利用效率更为低下。基于多层次水资源模拟与配置模型及其反算功能,解决了省控控制条件与不同层面水资源管理部门量化执行需求之间的脱节,为最严格水资源管理制度下的水资源利用考核提供技术支撑,为区域水资源管理提供示范与借鉴。     

A Fuzzy Robust Nonlinear Programming Model for Stream Water Quality Management

An interval-parameter fuzzy robust nonlinear programming (IFRNP) approach was developed for stream water quality management under uncertainty. The interval and fuzzy robust programming methods were incorporated within a general framework to address uncertainties associated with the nonlinear objective and the left- and right-hand sides of the constraints. A piecewise linearization approach was developed to deal with the nonlinear cost function. IFRNP could explicitly address complexities of various system uncertainties, where parameters were represented as both interval numbers and fuzzy membership functions. Furthermore, the dual uncertain information associated with the lower and upper bounds of each interval parameter could be effectively tackled through the concept of fuzzy boundary interval. The proposed IFRNP method was applied to a case of water quality management in the Guoyang section of the Guo River in Anhui province, China. A number of cost-effective schemes for water quality management were generated, and allowable wastewater discharge amounts were recommended. The results indicated that IFRNP was applicable to water quality management problems, where high nonlinearities and dual uncertainties exist.     

区域水资源与水污染控制系统综合规划

本文提出在区域范围内将水资源与水污染控制作为一整体进行综合规划。依据系统规划的目标关系,采用解释结构模型法,构建具有6个目标层次的系统综合规划目标体系;结合规划特点,将所建综合规划目标体系量化,以满足区域用水需求、改善水环境质量及系统年成本最低为目标,建立了多目标综合规划数学模型。将该方法用于北方某区域规划,其最佳方案可减少天然水资源开采量56％,提高污水处理率30%,再生水利用率32%,仅计算全区域使用再生水所节省的水资源费每年可达14143万元,具有显著的社会、经济与环境效益。     

Integrated Decision Support System for Prognostic and Diagnostic Analyses of Water Distribution System Failures

This paper presents an innovative decision support system (DSS) for prognostic and diagnostic analyses of water distribution system (WDS) failures. The framework of the DSS is based on four novel models developed and published by the authors of this paper. The four models include reliability assessment model, leakage potential model, leakage detection model, and water quality failure potential model. Information obtained from these models together with external information such as customer complaints, lab test results (if any), and historical information are integrated using Dempster-Shafer (D-S) theory to evaluate prognostic and diagnostic capabilities of the DSS. The prognostic capabilities of the DSS provide hydraulic and water quality states of a WDS whereas the diagnostic capabilities of the DSS help to identify the failure location with minimal time after the occurrence and will help to reduce false positive and false negative predictions. The framework has ‘unique’ capacity to bring the modeling information (hydraulic and Quality), consumer complaints, historical failure data, and laboratory test information under a single platform to perform a prognostic and diagnostic investigation of WDS failures (hydraulic and Quality). The proof of concept of the DSS has been demonstrated using data used in published four articles. The outcomes of this research widely addressed the uncertainties associated with WDS which improves the efficiency and effectiveness of diagnosis and prognosis analyses of WDS. It is expected that the developed integrated framework will help municipalities to make informed decisions to increase the safety, reliability and the security of public health.     

Adjustable Robust Optimization for Multi-Period Water Allocation in Droughts Under Uncertainty

Optimal water resource allocation can go some way to overcoming water deficiencies; however, its achievement is complex due to conflicting hierarchies and uncertainties, such as water availability (WA) and water demand (WD). This study develops a robust water withdrawal scheme for drought regions that can balance the trade-offs between the sub-areas and water use participants, ensure sustainable regional system development, and guarantee robust solutions for future uncertainties. A bi-level affinely adjustable robust counterpart (AARC) programming framework was developed in which the regional authority as the leader allocates water to the sub-areas to maximize the intra- and intergenerational equity, and the sub-areas as the followers allocate water to their respective water departments to maximize their economic benefits and minimize water shortages. A case study from Neijiang, China, is given to illustrate the applicability and feasibility of this framework. The novelty of this study is to propose a sustainable bi-level AARC regional water allocation framework which integrates intra- and inter-generational equity of regional water use and priority rules reflected by goal preference programming between water departments under uncertainties of WA and WD simultaneously in water deficient regions.

     

不确定条件下的多水源联合供水调度模型

本文针对城市供水调水系统中存在的不确定性与复杂性，运用区间两阶段随机规划的方法，建立了多水源联合供水调度的优化模型。该模型以供水调度系统成本最小为目标函数，模拟了地表水源、地下水源、外来水源等多种水源联合供水，并对多种水源的调水目标进行优化。以区间形式给出优化结果，为决策者提供宽裕的决策空间。利用该方法，可充分考虑系统中不确定因素对系统成本的影响，更真实的反映多水源联合供水系统的实际情况。     

Water Supply Network Optimisation Using Equal Flow Algorithms

Algorithms to optimise water supply networks are developed and compared when a given set of transfer arcs is constrained to carry the same (or proportional) amounts of flow. Initially, a dynamic multi-period mathematical model is designed as a network flow model. A network simplex-based algorithm, Equalflow, and a subgradient-based algorithm, SUBeqf, are then presented. Both algorithms are characterised by polynomial complexity and can solve large-scale instances that arise when considering water system requirements. A specialised interface for water supply networks provides a data input processor to generate the overall multi-period network model in the implementation of the procedures. The implementation of the algorithms allows the consideration of different types of equal flow instances that take place in water resource system optimisation. The performances of the two algorithms and analysis of their computational efficiency with respect to state-of-the-art mathematical programming software are reported, considering equal-flow instances from a synthetically generated network and two water supply systems in the Sardinia region of Italy.     

An Inexact Two-Stage Water Resources Allocation Model for Sustainable Development and Management Under Uncertainty

In this study, an inexact two-stage water resources allocation (ITWR) model is put forward for supporting sustainable development and management of water resources in Sanjiang Plain, China, which is in such a situation, with multi-water source, multi-water supply subarea, multi-water user and multi-planning goal. The costs of net system, water supply and recourse are analyzed. The developed ITWR model, which shows a strong ability in tacking with various uncertain factors in probability distributions and discrete interval numbers, mixes the techniques of interval-parameter programming (IPP) and two-stage stochastic programming (TSP) within a general optimization framework. And it also has formed an effective link in such a conflict between the policy scenarios and the associated various levels of economic penalties, when the pre-allocation targets of water resources are violated. Based on this model, a series of scenarios under different levels of pre-allocation water is done and different degrees of water surplus and shortage are obtained correspondingly. The results indicate that the reasonable distribution plans with maximum system benefit and minimum system-failure risk have been generated. And these results are valuable for saving water resources to realize its sustainable development and mitigating the penalty to gain economic benefits maximum, and thus some desired results are provided for decision makers in tackling with a complex and uncertain water-resource system.     

Optimal planning of water supply system for long-term sustainability

Developing a long-term system plan for sustainable water supply is a challenging task due to system complexity and future uncertainties in water demands and source availability. Here a coupled optimization model is proposed for water supply system design and long-term operations by deciding system component sizes and water flow allocations simultaneously. The objective is to minimize overall system costs (i.e., sum of capital and operation costs) while meeting water demands and operational constraints. The economic costs include initial component construction costs and operation expenditure over pre-defined operation years. The proposed model integrates a genetic algorithm with a linear programming model to optimize water infrastructure investments and annual water transfers satisfying flow constraints. The coupled model was applied to a simplified water supply network composed of multiple water sources and users. For the application network, various qualities of water from different sources could be supplied to different users. Plausible future scenarios with time varying water demands were simulated representing potential future conditions. Application results show that the proposed coupled model is beneficial in decision making process to design structural components in near future and prepare long-term policies for water shortage and water right issues in upcoming years. The model can be tailored to a specific system and various regulations and conditions can be incorporated within the model without adding complexity to the optimization framework.     

Water Resource Models in the Mekong Basin: A Review

Development of the water resources of the Mekong Basin is the subject of intense debate both within the Mekong region and internationally. Water resources modelling is playing an increasingly important role in the debate, with significant effort in building integrated modelling platforms to describe the hydrological, ecological, social and economic impacts of water resource development. In the hydrological domain, a comprehensive set of models has been effective in building understanding of the system, and in identifying and describing the issues and trade-offs involved in basin-scale water planning. In the ecological and social domains, quantitative modelling has not progressed very far; geo-spatial analysis and qualitative frameworks remain the most commonly used tools. Economic models have been used to assess the costs and benefits of water resources development and to describe the trade-offs between different sectors and users. These analyses are likely to play an important role in the policy and planning debate, but are hampered by uncertainties in valuation of ecosystem services. Future efforts should focus on optimising the use of existing model platforms for the Mekong, including structured comparison of multiple hydrological models to quantify errors and identify an optimum set of modelling tools for different applications. A comprehensive research effort is needed to incorporate groundwater into hydrological models for regional planning. Options for social impact assessment should be reassessed before major investments are made in complex modelling platforms, and participatory social survey methods evaluated as part of an integrated assessment framework.     

串联水库联合供水的风险分析

为干流多个串联水库与地下水库联合对区域供水系统建立风险分析模型。以系统分析的思想为基础，考察来水和用水的不确定性，利用地表水和地下水联合调配数学模型，采用随机模拟技术对串联水库联合供水的风险进行定量描述。对石家庄地区的分析计算结果表明，该方法充分考虑了区域工农业需水量约束和生态环境需水约束，得出的结论对区域决策具有参考意义。