Nested Optimization Approach for the Capacity Expansion of Multiquality Water Supply Systems under Uncertainty

A nested optimization approach is proposed to solve capacity expansion problems of multiquality water supply systems. The problem to be solved consists of determining the infrastructure that should be built and/or rehabilitated at a specific time. This decision should be taken in a long-term planning perspective. It should consider how the operation will be performed to satisfy demand and water quality requirements by using multiple sources with different water quality at the source, take into account the temporal and spatial distribution of the water resources available and remain aware of the environmental impacts. In addition, decision processes which do not appropriately consider inherent uncertainties (e.g., hydrological, demographic, and technological uncertainties) can lead to suboptimal solutions. Here, uncertainty is handled using scenario planning with the aim of finding expansion solutions that can be expected to perform well under a set of possible future situations (or scenarios). The solution method combines simulated annealing with nonlinear programming to determine the solution to the nested optimization problem.     

城镇供水管网监测自动化系统设计

通过分析管网系统组成与运行要求,选取相应监测点及监测仪器,建立一套实时快速、准确可靠、先进实用、高度自动化的信息采集、监测与控制的自动化系统,以便对供水管网的安全运行状态、水情信息以及设备的运行等进行实时监测与控制,为供水安全可靠、水资源优化配置等提供决策支持手段,进一步提高管理决策的水平和效率。     

Design of Water Distribution Network for Equitable Supply

Water shortage is experienced in different parts of the world in different magnitude. In certain countries, water deficit is a regular phenomenon and in some other countries it happens for a short duration, due to failure of any component in the system. Shortage of water at source can be best tackled by distributing the available water equally among the consumers. This paper deals with the design of water distribution network capable of equitable supply during shortage in addition to the satisfactory performance under non-deficit condition. Performance of a typical water distribution network, with shortage of water at source is illustrated in detail. Head dependent outflow analysis with extended period simulation, is used to determine the actual supply from each node to consumers. Relationship between duration of supply and volume available at source as well as supply from each node are established for understanding the behaviour of network under low supply situation. A term “inequity” which is the maximum difference in supply demand ratio among different consumers is presented. This is based on the actual performance of the network instead of surrogate measures, generally used for reliability. It is illustrated that the maximum “inequity” in supply in a network during the entire duration of supply can be estimated with single analysis. Design of a water distribution network, duly considering equity in addition to the cost minimization and minimum head requirement is presented. Genetic Algorithm is used for solving this multi objective problem. The solution technique is illustrated using two benchmark problems, namely two loop network and Hanoi network. Results show that considerable improvement in equitable supply can be achieved with additional investment on pipes above the least cost solution. Hence it is better to design networks duly considering deficit condition for better reliability. It is also illustrated that it will be difficult to improve equity beyond a limit for a given network, through selection of different pipe diameters.     

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.     

东深供水改造工程全线计算机监控系统设计

介绍东深供水改造工程全线计算机监控系统的系统设计及其思路，主要阐述监控系统的任务要求、结构配置特点和实现功能，重点强调监控系统设计的关键技术和技术创新、先进性，以便为国内外同类工程提供借鉴．     

东深供水改造工程综合通信传输网络设计

东深供水改造工程综合通信传输网络围绕“泵站无人值班，远方调度控制”的工程建设目标，结合工程全线监控系统、语音系统、图像监视系统、会议电视系统的传输需求，组成一个适用于综合性多媒体通信网络的工程专用传输网络．从介绍工程对通信网络的传输需求入手，主要介绍综合通信传输网的网络结构、配置及其功能特点．     

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.

     

基于遗传算法的农村供水管网优化设计

农村饮水安全工程的供水管网优化设计,对于节约工程投资、提高工程社会效益具有重要意义。为了对供水管网进行管径优化,从经济性和可靠性出发,以投资成本最低为目标函数,以水力学指标为约束条件,建立管网优化数学模型。运用遗传算法进行模型求解,针对供水管网优化模型的特点,选取自然数编码,建立合适的适应度函数,设置选择、交叉、变异等遗传算子,并选取工程实例进行优化求解,通过与传统方法的计算结果对比,验证了遗传算法用于供水管网优化的实用性。     

水环境容量的不确定性分析计算

水文系统是未确知系统。用水文资料推求设计标准下的河段水量时,不同的方法、不同的系列很可能得到不同的结果,所以由此计算的水体环境容量也具有不确定性。基于这种特点,采用未确知数学理论进行分析计算,可得到更趋于合理的河段水环境容量结果,其结果有明确的可信度概念。     

Intermittent Water Supply under Water Scarcity Situations

Abstract

This paper describes the recently developed ‘Guidelines for the design and control of intermittent water distribution systems’. These guidelines outline a new approach to the design of urban water distribution systems for developing countries in order to maintain adequate and equitable supplies under the common conditions of water resource shortage. The guidelines are novel in that they recognise the reality of intermittent supply and hence provide new methods of analysis and design, appropriate for such systems. Design objectives specifically tailored to intermittent systems are developed and drive the design process. These objectives are expressed in terms of equity in supply, adequate pressure at water connections and duration or time of supply that are convenient to the consumers. The modifications required to model such systems have been incorporated into a new network analysis simulation tool coupled with an optimal design tool.     

遗传算法实现农村树状供水管网的优化设计

为改善农村树状供水管网的管径设计方案,应用数学建模和最优化理论,提出在确定管网布置方案的基础上,采用整数编码的遗传算法,建立管径组合方案优化模型。以经济性作为目标函数,并结合实例,编制相应计算程序,对某一农村供水管网进行优化设计,与传统设计方案进行对比。结果表明,该优化设计方案在经济性和水力特性都优于传统的设计方案。     

Resilience Indexes for Water Distribution Network Design: A Performance Analysis Under Demand Uncertainty

Traditionally, the optimal design of water distrubution networks has been dealt with using single-objective constrained approaches, where the aim is to minimize the network investment cost while maintaining minimum pressure head constraints at all nodes. However, in the last decade some authors have proposed multi-objective approaches which optimize other objectives than network investment cost. In most cases, these objectives have been formulated using the concept of resilience index, which mimics the design aim of providing excess head above the minimum allowable head at the nodes and of designing reliable loops with practicable pipe diameters. Although several authors have proposed different resilience indexes for this pupose, to date there is no empirical study that analyzes the advantages and disadvantages of these proposals. This paper evaluates the performance of a well-known multi-objective evolutionary algorithm, the Strength Pareto Evolutionary Algorithm 2, using three different resilience indexes. The results obtained in two water supply networks under a large number of simulated over-demand scenarios show the advantages and disadvantages of these measures.     

自来水公司网络构建及实现

综述了自来水公司构建计算机网络时系统结构、局域网、广域网、网络产品、操作系统等的选型 ,所要考虑的问题和应用效果。     

龙潭水库经济评价及其不确定性分析

以龙潭水库引水工程的实例，进行了国民经济评价、财务评价和不确定性分析，通过对该工程的不确定性分析，说明了敏感性分析和盈亏平衡分析的不同的适用范围和优缺点。     

非市政给水用作消防水源的探讨

从节水的角度 ,对天然水源、工业废水回用水、建筑中水用作消防水源时的水质要求 ,以及设计中的注意事项等问题进行了探讨 ,并对规范中有关条文提出了修改意见     

海岛地区提高水资源保障能力对策探析——以舟山市为例

在调查舟山市水资源开发利用现状的基础上,分析海岛地区水资源开发利用与保护中存在的问题。坚持从海岛实际出发,提出了提高水资源保障能力的思路,积极实施引水、蓄拦水、非常规水、联网、节水、净水等联动战略,促进海岛地区水资源的可持续利用。     

基于GIS和SCADA技术的供水管网信息管理系统设计

阐述了实现供水管网GIS系统与SCADA系统一体化设计的必要性,提出了系统设计方案,实现了GIS和SCADA系统在技术上的互补,增强了模型可视化分析能力。通过实例验证,表明该系统具有较强的实用价值。     

茂名市农业节水水平对供水能力的影响分析

本文基于茂名市水资源状况、 开发利用潜力、 区域经济结构与发展规划、 水生态环境问题等特点,结合农业灌溉节水水平、 水资源开发利用空间布局、 以及经济定位等,构建不同农业节水水平模拟情境,从灌区节水改造、 农业种植结构调整等方面,分析农业节水对茂名市供水能力的影响,为茂名市农业节水措施及水资源优化利用研究方向提供参考依...