Efficiency of Urban Water Supply Utilities in India

The two parameters of services output of water utilities are the per capita water available for consumption and the hours for which water is supplied per day. However, water utilities in India differ on the level of these outputs substantially. This paper uses the data for water utilities in 31 cities to analyse their performance in delivery of services. Using data envelopment analysis, a measure of technical efficiency for various utilities is calculated. The results indicate that water utilities can increase the delivery of water on a per capita basis and increase the hours of supply per day by about 18%. Nearly 37% of the increase in services could result from changing the scale of operation. This paper also discusses if the institutional framework within which these utilities operate has implications on their efficiency.     

Assessing the Vulnerability of California Water Utilities to Wildfires

Water Resources Management - Wildfires are becoming more frequent and destructive in California, and it is essential to quantify their potential impacts on drinking water utilities. This study aims...     

数据包络分析在城市供水效率评价中的应用

为了提高城市供水效率,缓解我国城市用水危机,首先应对城市供水效率进行科学地评价,这是一个复杂的多指标综合评价的问题。在详细分析众多城市供水效率评价因素的基础上,建立了基于数据包络分析理论的城市供水效率相对有效性的评价模型,并将该模型应用于实际之中,结果表明该方法不仅对输入、输出数据有很大包容性,而且不需要预先给出指标的权重,比传统方法更加方便、有效。     

Critical Elements Analysis of Water Supply Systems to Improve Energy Efficiency in Failure Scenarios

Water supply systems (WSS) are significant energy consumers, which makes it crucial to find methods to increase energy efficiency. A novel approach is presented here to locate and quantify the most vulnerable elements in terms of energetic efficiency. The method is based on a linear programming (LP) optimization model and the elimination of different components in the system to analyze their impact on energy costs. Pump reallocation is then suggested as a novel dynamic design paradigm for temporary changes in the system to cope with extreme scenarios. Exposing the critical components of WSS improves maintenance prioritization and inventory and contributes to the planning of future investments in the system. Pump reallocation provides an innovative approach for response to critical conditions, it is suggesting rethinking the design concepts to incorporate not just long-term solutions but also rapid, temporary steps in response to failures.

     

使用 R 对 1995-2011 年我国水资源状况的分析

缓解水资源危机,合理开发利用水资源,关键是从时空维度量化水资源,分析和挖掘出有价值的知识和规律。R是一种免费的软件,具有丰富的统计计算和图形展现等功能,已成为大数据分析、挖掘和展现的利器。在概述水资源数据特点的基础上,以1995—2011年全国各省份水资源统计数据集为例,介绍如何使用R对水资源数据进行分析,包括假设检验、趋势分析等。结果既能通过图形化方式清晰直观地看到不同地区、省份的空间维度下,水资源按时间的变化情况,也可以快速选择出最佳趋势拟合方式等,符合领域业务要求。     

Design of a Control System Using an Artificial Neural Network to Optimize the Energy Efficiency of Water Distribution Systems

Sustainable management of water supply systems is a major challenge within the framework of the water-energy nexus. The main strategies to improve the operation of these systems are related to increasing the hydraulic and energy efficiency of pumping systems. In this context, this work presents a new artificial neural network (ANN) controller to improve the operation of water distribution systems (WDSs) that includes in its algorithm the specific energy consumption (SEC) as a decision parameter. Therefore, pressure control at the measuring points is also based on the energy efficiency of the pumps. The technique was applied to control the pressures in an experimental setup that emulates a WDS with two consumption zones with different topographies. For this purpose, the controller acted on a conventional pump, a booster pump and a control valve. To analyze the performance under the controller action, tests were performed emulating water-demand scenarios, introducing perturbations and changing the pressure setpoints. The real-time control performance was proven based on the dynamic performance, steady-state performance and SEC. The experimental results showed that the proposed controller kept the pressures close to the setpoints and provided a reduction in the SEC between 15.1% and 17.8%, compared with the uncontrolled system, and an economy that varied from 2.5% to 8.1% compared with the performance of the ANN based only on pressure control.

     

Urban Water Management Using Fuzzy-Probabilistic Multi-Objective Programming with Dynamic Efficiency

This paper introduces a new multi-objective optimization model for integrated urban water management. The model, based on compromise programming, is applied for the case of Tabriz city in Iran. The water demand of this city is rapidly growing and because of the limited resources, water supply is now more vulnerable to any mismanagement. Therefore the model attempts to optimize the water supply plan of city concerning three main objectives of maximizing the water supply, minimizing the cost and minimizing the environmental hazards. Due to the vagueness in defining the first objective, it is modeled by using the fuzzy set theory. Further, the uncertainty in satisfying some constraints is tackled by using the chance constraint approach. The decision variables are the extent of water withdrawal from the city aquifer, three different water transfer schemes and also the extent of demand management by leaks detection and pipes rehabilitation. Then the fuzzy-probabilistic multi-objective model is solved by considering the new idea of dynamic efficiency in the utility of decision maker and the results provide the optimum water supply in the planning horizon. The model results in robust solutions in which the demand management option dominates the new water transfer. Implementing the results of this model supports the environmental conservation and sustainable development.     

Assessing the Accuracy of Soil and Water Quality Characterization Using Remote Sensing

Assessing the risks of agricultural management practices on agro-ecosystem sustainability has special relevance in Ohio, USA due to the states prominence in agricultural production. However, identifying detrimental management practices remains controversial, a situation that may explain the inability to halt the recurring harmful algal blooms in inland waters, or the build-up of nutrients in the agricultural soils. Thus, detailed and accurate information is required to identify soils and water susceptible to degradation, and to support counteractive remedial measures. In this study soil and water spectral reflectance data were acquired with an Analytical Spectral Device, and modeled with laboratory measured physical and chemical properties using the Analysis of Variance (ANOVA) and decision trees. Results reveal no site differences in pH for the water, but the differences in electrical conductivity (EC) were significant. Similarly, the pH for soils did not vary significantly with depth increments. However, the no till (NT) managed soils had significantly higher pH. EC varied with depth of the water, whereas the soil carbon: nitrogen (C/N) ratio varied with management in 4 out of 5 sites. Finally, this study shows that remotely sensed data can be utilized to effectively characterize agricultural management practices based on inherent soil and water properties, thus providing information critical for assessing the efficacy of Water Quality Trading initiatives.     

Water Consumption Variability Based on Cumulative Data From Non-simultaneous and Long-term Measurements

Water Resources Management - Devices for water consumption measurement provide data from periodical readings in a non-simultaneous and cumulative manner. This may result in inaccuracies within the...     

Ownership, Investment Policies and Funding Choices of Italian Water Utilities: An Empirical Analysis

Nowadays, the efficient management of water has become the focus of vast debate, both in the academic literature and in the practical and regulatory field. Due to the growing importance and scarcity of water resources, it has become crucial to better understand how to improve the organizational efficiency of water utilities. By adopting an accounting perspective and using statistical methods, this paper analyzes whether and to what extent investment and financial strategies differ among clusters of water utilities with different ownership structures. The paper focuses on the Italian water industry, a context considered particularly appropriate due to the coexistence of utilities with different ownership structures. The main results of the paper show that ownership affects the level of investment as well as the financial structure and costs of water utilities. The evidence provided by this study should encourage national governments and regulatory authorities to select water utilities with the greatest investment potential measured in terms of financial efficiency and effectiveness.     

基于层次分析法的云南省小康水利现状评估

云南省开展小康水利规划研究,力争在2020年实现小康社会下的小康水利。为确保这一目标的顺利实现,基于层次分析法提出了由防洪抗旱减灾、水资源合理配置、水资源高效利用、水源地保护与河湖健康保障、水管理、水利发展保障6大体系26项指标组成的云南省小康水利评价指标体系。通过层次分析法计算各项指标权重,并利用构建的小康水利指标体系对云南省2011年水利发展现状进行评价。云南省小康水利现状水平为71分,距离实现小康水利还有一定差距。水管理能力得分仅为40.8分,为主要制约因素,这与云南省水利发展现状基本相符,现状评估结果可为云南省小康水利建设规划提供依据。     

惠州抽水蓄能电站能效分析

综合效率是评价抽水蓄能电站节能与否的重要指标,它从根本上反映电站节能水平。对抽水蓄能电站的能源流程进行了分析,针对抽水蓄能电站现有估算的综合效率的数据异常问题进行了探讨,结果表明这一现象主要是由于统计周期内水量不平衡所导致的。通过比较分析估计效率与循环效率,在考虑水量平衡以及上库水量的蒸发渗漏后完善了综合效率计算方法,并从整个电站水资源综合利用的角度出发,定义计算了综合能效。还利用惠州抽水蓄能电站的数据进行了综合效率与综合能效计算,系统地分析了能源流程各环节的能耗情况,并得出了相应的结论。     

基于模糊集对分析-五元减法集对势的新疆水资源承载力评价

为定量评价新疆各地州水资源承载力状况、识别需要进行水资源承载力调控的地区,建立了新疆水资源承载力指标体系与评价等级标准,构建了模糊集对评价模型,结合五元减法集对势对新疆15个地州水资源承载力进行评价并诊断其发展态势.结果表明:新疆水资源承载力呈现出北疆较好、南疆其次、东疆稍弱的情况,评级为Ⅰ级的地区占13.4％,Ⅱ级占...     

Assessing the Impact of Climate Change on Future Water Demand using Weather Data

Water Resources Management - Assessing the impact of climate change on water demand is a challenging task. This paper proposes a novel methodology that quantifies this impact by establishing a link...     

Generating Monthly Stream Flow Using Nearest River Data: Assessing Different Trees Models

Water Resources Management - The data-driven techniques have gained more attention in stream flow prediction in recent years. In the current study, three different trees models (random forest,...     

Prioritizing Long-term Watershed Management Strategies Using Group Decision Analysis

There is a growing consensus that an effective way of enhancing long-term water resources management and environmental sustainability is through locally based planning at the watershed scale. Managing watershed resources for particular uses requires interactive dialogue among all stakeholders who have different objectives. Therefore, the resolution of inter-group conflict should be an acknowledged task of the planning process. In this paper, an integrated framework for prioritizing watershed management strategies is proposed. A case study is employed to highlight the challenges of using group decision analysis in strategic planning and to illustrate the interaction between different stakeholders on watershed issues. In particular, two group decision-making approaches are used to assess and analyse different stakeholders' preferences for various strategies and alternatives. Professional experts, government agencies and community leaders constitute the different parties included in the framework. The main focus is on the application of group decision analysis in the long-term watershed planning process. The results of the overall preference analysis show that water resources development is the most important strategy followed by agricultural and range management.     

某冶炼厂用水合理性分析与探讨

随着国家环保要求日益严格,冶炼厂对工艺技术进行了改造和提升,工艺和装备水平有了明显的改进和提高,然而在冶炼技术方面的弱点也越来越突出。本着有利于发展产业集群,促进地方经济增长,保护水资源,严格执行最严格水资源管理制度,促进水资源合理开发利用和节约用水,保障经济社会可持续发展的理念,以某冶炼厂为例探讨冶炼厂用水工艺及合理用水量,为冶炼厂用水合理性分析提供参考。     

Water Services are the Bridgehead for a Return to Publicly Owned Utilities in Europe. A Comparative Analysis

Although for decades all across Europe numerous privatization phenomena have involved utilities, today the European Union appears on the edge of a profound change and water services are undoubtedly the bridgehead of a new model. Firstly, in a comparative perspective the present analysis aims to find some clues of the new trend at the national level. In particular, it moves from a case-based approach in order to carry out a wider exam of the relevant regulatory schemes. It thus focuses on the referenda concerning water supply services that took place in Italy and Germany. Plus, it studies local government decisions on the matter in the context of a debate regarding public companies, as in France. Secondly, the present paper gives an overview of the current water regulatory framework at European level. Directive 2000/60/EC gives a peculiar definition of water as a heritage rather than a commercial product as any other. Directive 2014/23/EU excludes water sector from the scope of the new concession regulatory scheme, given that water is a public good of fundamental value to all Union citizens. Besides, Directive 2014/25/EU clearly states that no by no means Member States are obliged to externalize the provision of water services, if they prefer to organize them in ways alternative to procurement. Eventually, the present article stresses out the new favourable background for re-publicisation processes set forth by the current European Union law.     

Probabilistic Water Demand Forecasting Using Projected Climatic Data for Blue Mountains Water Supply System in Australia

Long term water demand forecasting is needed for the efficient planning and management of water supply systems. A Monte Carlo simulation approach is adopted in this paper to quantify the uncertainties in long term water demand prediction due to the stochastic nature of predictor variables and their correlation structures. Three future climatic scenarios (A1B, A2 and B1) and four different levels of water restrictions are considered in the demand forecasting for single and multiple dwelling residential sectors in the Blue Mountains region, Australia. It is found that future water demand in 2040 would rise by 2 to 33 % (median rise by 11 %) and 72 to 94 % (median rise by 84 %) for the single and multiple dwelling residential sectors, respectively under different climatic and water restriction scenarios in comparison to water demand in 2010 (base year). The uncertainty band for single dwelling residential sector is found to be 0.3 to 0.4 GL/year, which represent 11 to 13 % variation around the median forecasted demand. It is found that the increase in future water demand is not notably affected by the projected climatic conditions but by the increase in the dwelling numbers in future i.e. the increase in total population. The modelling approach presented in this paper can provide realistic scenarios of forecasted water demands which would assist water authorities in devising appropriate management strategies to enhance the resilience of the water supply systems. The developed method can be adapted to other water supply systems in Australia and other countries.