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.     

Sustainability Assessment of Urban Water Distribution Systems

A methodology is presented for determining sustainability indices for pressure and water age in water distribution systems (WDSs). These sustainability indices are based upon performance criteria including reliability, resiliency, and vulnerability. Pressure and water age are determined for a WDS as a function of operation time using the U.S. Environmental Protection Agency EPANET model. The values of pressure and water age are used to determine reliability, resiliency, and vulnerability performance criteria, which are then combined into the nodal sustainability indices for water age and pressure. In addition, the sustainability index (SI) computations are performed for zones to define the SI for water age and SI for pressure. A combined SI calculation is performed to produce an overall sustainability score for the entire zone in the water distribution network. The proposed methodology can be used to monitor the sustainability of existing WDSs and to help define alternative solutions including changes in pump operation and modifications to WDS to increase the sustainability.     

河流健康检测:水可持续发展评估和河流可持续发展指数

水是最重要的资源之一,随着人口和经济增长,水资源短缺和退化对社会经济发展和环境保护构成了日益严重的威胁。为人类各种竞争性用水提供充足的淡水资源已成为更具挑战和关键的问题。维护和恢复河流健康系统已经成为环境和水资源管理的重要目标。为了解这些挑战,实现未来水管理的可持续发展,有必要对河流健康进行综合评估。河流健康评估工具已经发展到测量河道的生态状况和自然资本。基于将河流健康测量延伸至包含水资源的社会经济价值,本文提出一个用于评估河流可持续性的指标框架,讨论了可持续发展指标如何用于评估水可持续性发展的具体问题,介绍了我们所采用的可持续发展评估的过程分析方法,以及由此方法得到的中国黄河下游可持续发展综合指数。该方法提供了一种系统方式,以纳入可持续发展的所有领域,并可生成一套定制指标。本文认为可持续发展指标框架为评估河流的可持续性提供了透明和参与的基础。这种评估为关键问题识别提供了信息和概貌,尤其对支撑政策制定很有帮助。     

Technical and Environmental Sustainability Assessment of Water Distribution Systems

An environmental and technical sustainability assessment methodology is developed for both centralized and dual water distribution systems (WDSs) with and without fire flow scenarios. Technical sustainability of potable and reclaimed water networks is measured by a sustainability index (SI) assessment using reliability, resiliency, and vulnerability performance criteria. The U.S. Environmental Protection Agency EPANET software is used to simulate hydraulic (i.e. nodal pressure) and water quality (i.e. water age) analysis in a WDS. Total fresh water use and total energy intensity are considered as environmental sustainability criteria. The procedure considers two separate alternatives for meeting fire flows: (1) adding pumping to a system or (2) adding a non-potable WDS. The reclaimed system is designed using linear programming (LP) optimization. For each alternative, multi-criteria decision analysis (MCDA) is used to combine technical and environmental sustainability criteria for an urban WDS.     

农村饮水安全工程项目可持续性评估研究

针对农村饮水安全工程建设项目中存在的持续性不足的问题,探索了农村饮水安全工程项目可持续性评估的指标体系,构建了基于PPP模式的农村饮水安全工程可持续性评估模型,采用层次分析法并从工程项目的经济、社会以及环境效益角度出发,评估农村饮水安全工程建设的可持续性综合效益值。研究可为农村饮水安全工程建设的可持续性评估提供决策依据。     

An Entropy-Based Approach to Fuzzy Multi-objective Optimization of Reservoir Water Quality Monitoring Networks Considering Uncertainties

In this study, a new fuzzy methodology for a multi-objective optimization of reservoir Water Quality Monitoring Stations (WQMS) was developed, based on Transinformation Entropy (TE), the IRanian Water Quality Index (IRWQI), and fuzzy social choice considering uncertainties. The approach was utilized in the Karkheh Dam reservoir in Iran. The objective functions were: 1) minimizing costs, 2) minimizing redundant information and uncertainties, and 3) maximizing the spatial coverage of the network. A CE-QUAL-W2 model was used for the simulation of water quality variables. The IRWQI was computed to reveal a complete picture of the reservoir water quality. The TE quantities were calculated for each pair of potential stations. The TE values were plotted against the spatial distances among potential WQMS to obtain the TE–Distance (TE–D) curve, and minimize redundant information among stations, while providing coverage of the entire network. A multi-objective Genetic Algorithm (NSGA-II) was applied to obtain Pareto-optimal solutions taking stakeholder preference into account. The most preferred solution was then obtained using fuzzy social choice approaches to achieve a consensus. The fuzziness embedded in the decision-making procedure, the uncertainty in the value of mutual information, and the uncertainty in identifying the optimal distance among WQMS were also investigated. Results indicated that the three fuzzy social choice approaches (Borda Count, Minimax, and Approval Voting) led to the same number of optimized WQMS in each fuzzy alpha-cut. Based on the fuzzy linguistic quantifiers method, the number of optimized WQMS was increased.     

Assessment of Potable Water Savings in Office Buildings Considering Embodied Energy

The objective of this article is to assess the potential for potable water savings in office buildings located in Florianópolis, southern Brazil. The embodied energy of four alternatives to reduce potable water demand, i.e., rainwater harvesting, greywater reuse, dual-flush toilets and water-saving taps, was also assessed. The analyses took into account the potable water end-uses for ten buildings. The potential for potable water savings by using rainwater, as well as, the rainwater tank sizing were estimated using computer simulation. As for greywater reuse, it was considered that greywater from lavatory taps could be treated and reused to flush toilets. The potential for potable water savings by using water-saving plumbing fixtures was estimated by considering the replacement of toilets and taps. In order to estimate the embodied energy in the main components, each system was dimensioned and embodied energy indices were applied. The main result is that the potential for potable water savings by using dual-flush toilets ranges from 21.6 % to 57.4 %; by reusing greywater, it ranges from 6.8 % to 38.4 %; by using rainwater, it ranges from 6.1 % to 21.2 %; by using water-saving taps it ranges from 2.7 % to 15.4 %. However, by considering the embodied energy, the average for the ten buildings indicates that dual-flush toilets are the best choice as it is possible to obtain water savings of 5.50 m³/month per GJ of embodied energy, followed, respectively, by water-saving taps, greywater reuse and rainwater usage. The main conclusion is that the assessment of embodied energy should be considered when evaluating potable water savings in buildings as it helps to identify the best alternatives to save more water while causing less environmental impact.     

城市水系统环境可持续性评价框架

把社会水循环定义为水在人类社会经济系统的运动过程.立足社会水循环与自然水循环的匹配性,提出了一个社会水循环的概念模型.依据社会水循环概念模型探讨了城市水系统环境可持续性的评价目的、评价内容框架和评价准则框架,并提出了一组测评城市水系统环境可持续性的指标体系.该指标体系综合考虑了城市给水、用水和污水排放等系统,有效体现了城市水系统各要素的内在联系及其基本特征.     

Sustainability Issues in Water Management

In the 1992 Rio World Summit on Environment and Development/UNCED), water resources are indicated to remain at the core of sustainable development and, thus, they are to be managed and developed on a sustainable basis. Sustainability is a philosophical concept and thus difficult to measure. Yet, we need to describe it on rather precise terms to assess whether our water management practices are sustainable and to ensure sustainability in decision making for management. To this end, a number of sustainability criteria have been defined, based on quantifiable measures, without overlooking immeasurable aspects of sustainable development. This paper considers economic, social and environmental dimensions of sustainability as the basic criteria to be pursued in evaluating how effective our water management plans are in achieving sustainability. On the other hand, actual case studies are needed to test the usefulness of selected criteria by using computer-based interactive optimization and simulation models with associated databases embedded into a decision support system (DSS). The study herein intends to present such a case study based on economic, social and environmental criteria to assess sustainability in management of the Gediz River Basin in Turkey. Various management scenarios developed for the basin are evaluated within a DSS while ensuring multi-stakeholder involvement in defining the three sustainability criteria. The case study is a result of the analyses carried out in SMART (Sustainable Management of Scarce Resources in the Coastal Zone) and OPTIMA (Optimization for Sustainable Water Resources Management) projects funded respectively by the 5^th and 6^th Framework Programmes of the European Union.     

基于生态需水的水资源供需平衡分析

以山东省莱芜市为例,考虑河道内生态需水和河道外生态需水,分析了其水资源供需平衡状况。结果表明:2005年莱芜市用水量约等于供水量,社会经济用水稳定供应,社会经济系统的发展未因水资源问题而受到影响,水资源总量供需平衡;未来莱芜市水资源需求平衡指数大于1,且有变大趋势,说明其缺水将越来越严重;若加强需水管理,则未来平水年平衡指数小于1,基本能保持水资源供需平衡。     

Risk-Based Design of Flood Control Systems Considering Multiple Dependent Uncertainties

Due to random behavior of flood events and inaccuracies in measurements, design, analysis, and operation of flood control systems are subjected to several uncertainties. An important aspect in developing stochastic models for evaluating and analyzing more than one uncertainty is the dependence or independence of them. In flood control projects, hydrologic, hydraulic, geotechnical, and economic uncertainties are important considerations. In this paper, a stochastic Monte-Carlo simulation – optimization modeling approach is described for risk-based design of flood control levees (as a common structural flood control measure): considering multiple dependent uncertainties. It has been applied to the Leaf River reach in Hattiesburg, Mississippi for testing and evaluation of modeling results. Unlike a deterministic model that yields just one set of values for system dimensions, the stochastic model solution gives a range of values for each of them. One of the major reasons for limited field application of uncertainty analysis is difficulties in performing the modeling results in real world contexts. For closing the gap between theory and reality, design charts are developed in this study. This helps decision makers in identifying design values with desired and accepted risks.     

21世纪珠江片水供求概述

针对珠江片供水体系中存在的工程设施不足、水资源开发利用程度低、农业灌溉发展缓慢、水质污染严重等问题 ,提出未来供水体系应当如何满足社会经济发展要求 ,为水资源管理工作者提供决策参考。     

Measuring Sustainability in Israel's Water System

Abstract

Sustainability of water resources is often gauged as the gap between supply and projections of demand. This static view, however, is insufficient to judge the ability of a system to cope with uncertainty and variability, and does not monitor progress towards sustainability. That is, sustainability should be viewed as a process, not a goal. Commonly used performance indicators such as reliability, resiliency, and vulnerability are some aspects of the concept of sustainability. They are easy to use, can monitor trends, and can be adapted to account for changes in physical and social systems that affect the concept of sustainability. The case of Israel is considered as illustration. The water system and agricultural production dependent on it have exhibited high vulnerability and low resilience and reliability, in spite of change to the master water plan at the beginning of the 1990s.     

Assessing Framing of Uncertainties in Water Management Practice

Dealing with uncertainties in water management is an important issue and is one which will only increase in light of global changes, particularly climate change. So far, uncertainties in water management have mostly been assessed from a scientific point of view, and in quantitative terms. In this paper, we focus on the perspectives from water management practice, adopting a qualitative approach. We consider it important to know how uncertainties are framed in water management practice in order to develop practice relevant strategies for dealing with uncertainties. Framing refers to how people make sense of the world. With the aim of identifying what are important parameters for the framing of uncertainties in water management practice, in this paper we analyze uncertainty situations described by decision-makers in water management. The analysis builds on a series of “Uncertainty Dialogues” carried out within the NeWater project with water managers in the Rhine, Elbe and Guadiana basins in 2006. During these dialogues, representatives of these river basins were asked what uncertainties they encountered in their professional work life and how they confronted them. Analysing these dialogues we identified several important parameters of how uncertainties get framed. Our assumption is that making framing of uncertainty explicit for water managers will allow for better dealing with the respective uncertainty situations.     

A Hierarchical Index System for Analysis of Water Supply-Demand Situation

Water Resources Management - An accurate analysis of water supply-demand situation is essential to solve the increasing contradiction between water resources distribution and socioeconomic...     

灌区水资源供需系统干旱风险机制分析

为了给灌区防灾抗旱工作提供理论支撑,根据灾害学理论,对灌区水资源供需系统干旱风险进行了定义。在灌区旱灾形成中,致灾因子、孕灾环境与承灾体缺一不可,降水偏少是导致旱灾的直接致灾因子,农作物是最主要的承灾体。致灾因子、孕灾环境与承灾体三者相互作用,形成了一个具有一定结构、功能、特征的复杂体系,当它们之间的平衡被打破时,就会形成旱灾。致灾因子的危险性、孕灾环境的风险性和受灾体的脆弱性决定了旱灾的大小。     

水电可持续性评估工具简析

水电可持续性评估工具旨在对水电工程或流域水电开发的可持续性进行量化评估,以指导其未来的开发与管理.以国际水电协会与湄公河委员会分别推出的《水电可持续性评估规范》与“水电可持续性快速评估工具”为研究对象,对两者的评估范围、评估主题与准则、评估形式等进行比较分析,借此结合我国水电特点与政策法规,提出建立符合我国国情的水电可持续性评估工具的基本原则,为评估工具的进一步开发提供参考.     

Prior Assumptions for Leak Localisation in Water Distribution Networks with Uncertainties

Water Resources Management - Hydraulic model-based leak (burst) localisation in water distribution networks is a challenging problem due to a limited number of hydraulic measurements, a wide range...     

Basin Scale Water Resources Systems Modeling Under Cascading Uncertainties

Global change in climate and consequent large impacts on regional hydrologic systems have, in recent years, motivated significant research efforts in water resources modeling under climate change. In an integrated future hydrologic scenario, it is likely that water availability and demands will change significantly due to modifications in hydro-climatic variables such as rainfall, reservoir inflows, temperature, net radiation, wind speed and humidity. An integrated regional water resources management model should capture the likely impacts of climate change on water demands and water availability along with uncertainties associated with climate change impacts and with management goals and objectives under non-stationary conditions. Uncertainties in an integrated regional water resources management model, accumulating from various stages of decision making include climate model and scenario uncertainty in the hydro-climatic impact assessment, uncertainty due to conflicting interests of the water users and uncertainty due to inherent variability of the reservoir inflows. This paper presents an integrated regional water resources management modeling approach considering uncertainties at various stages of decision making by an integration of a hydro-climatic variable projection model, a water demand quantification model, a water quantity management model and a water quality control model. Modeling tools of canonical correlation analysis, stochastic dynamic programming and fuzzy optimization are used in an integrated framework, in the approach presented here. The proposed modeling approach is demonstrated with the case study of the Bhadra Reservoir system in Karnataka, India.