Serviceability evaluation of water supply networks under seismic loads utilizing their operational physical mechanism

The serviceability of water supply networks(WSNs)under seismic loads has significant importance for estimating the probable losses and the impact of diminished functionality on affected communities.The innovation presented in this paper is suggesting a new strategy to evaluate the seismic serviceability of WSNs,utilizing their operational physical mechanism.On one hand,this method can obtain the seismic serviceability of each node as well as entire WSNs.On the other hand,this method can dynamically reflect the propagation of randomness from ground motions to WSNs.First,a finite element model is established to capture the seismic response of buried pipe networks,and a leakage model is suggested to obtain the leakage area of WSNs.Second,the transient flow analysis of WSNs with or without leakage is derived to obtain dynamic water flow and pressure.Third,the seismic serviceability of WSNs is analyzed based on the probability density evolution method(PDEM).Finally,the seismic serviceability of a real WSN in Mianzhu city is assessed to illustrate the method.The case study shows that randomness from the ground motions can obviously affect the leakage state and the probability density of the nodal head during earthquakes.

Water Supply Networks as Cyber-physical Systems and Controllability Analysis

Cyber-physical systems (CPS) is a system of systems which consists of many subsystems that can stand alone in an individual manner and can be taken as a typical complex network. CPS can be applied in the critical infrastructures such as water supply networks, energy supply systems, and so on. In this paper, we analyze the structure of modern city water supply networks from the view of CPS theory. we use complex network theory to build an undirected and unweighted complex network model for the water supply networks to investigate the structural properties, and present the structure of the water supply networks and detect communities by a spectral analysis of the Laplacian matrix. Then, we analyze the structure and controllability of water supply networks by the structural controllability method. The results show the feasibility and effectiveness of the proposed complex network model. © 2014 Chinese Association of Automation.

Selection of Water Transmission Method and Analysis of Pipe Network Zoning in Municipal Water Supply and Drainage Design

With the acceleration of urbanization,the demand for water supply and drainage pipe networks has increased significantly.In the planning of urban construction,it is necessary to optimize the design of the water supply and drainage system pipe network to effectively save energy while providing residents with more accessible water resources.Therefore,the municipal water supply and drainage system and the water transmission methods should be designed according to the geographical conditions of the city.In this paper,we mainly analyze the design of municipal water supply and drainage systems and the selection of water transmission methods.Besides,the optimization of the water supply and drainage network zoning process and pipe network maintenance is also discussed,so as to provide a reference for municipal water supply and drainage work.

Impact of the Condition of Drinking Water Supply Networks on the Quality of Water Intended for Consumption: The Case of the Network in the Commune of Daloa (Central West of Côte d’Ivoire)

The potability of drinking water depends not only on the source and the treatment system, but also on the quality of the waterworks. In fact, the quality of drinking water is considerably degraded by the dilapidated state and lack of maintenance of drinking water networks. In Côte d’Ivoire, the majority of drinking water networks in the various towns are ageing. In Daloa, despite the efforts made by the company in charge of water treatment and distribution to make the water drinkable, the water at consumers’ taps is often colored, has an unpleasant aftertaste and settles after collection. As a result, people are concerned about the potability of tap water, and some are turning to alternative sources of drinking water of unknown quality. In order to determine the factors responsible for the deterioration in water color and taste, as well as the sectors of the network most affected, a diagnosis of the network’s equipment was carried out. Water samples taken from the network were analyzed for color and turbidity. The diagnosis revealed that most of the equipment (suction pads, valves, drains and fire hydrants) is outdated and irregularly maintained. Analyses show that the water is more colored in cast-iron and PVC pipes than in asbestos cement pipes. Coloration values in the network range from 0 to 27 UVC for asbestos cement pipes, from 15 to 56 UCV for ductile iron pipes, and from 11 to 102 UCV for PVC pipes. On the over hand, turbidity values vary from 8.02 to 3.32 NTU for ductile cast iron pipes, 8.51 to 16.98 NTU for asbestos cement pipes and 0.9 to 6.98 NTU for PVC pipes. Old cast-iron pipes release ferric ions on contact with water, degrading their color. Old cast-iron pipes release ferric ions into the water, degrading its color. The high color values observed in the vicinity of drains are thought to be due to irregular maintenance of the network. In fact, after network maintenance, a reduction rate ranging from 2% to 73% is observed for turbidity, while for color, the rate varies from 5% to 72%. In short, the network’s obsolescence and irregular maintenance contribute significantly to the deterioration of water quality.

Multi-objective optimization of water supply network rehabilitation with non-dominated sorting Genetic Algorithm-II

Through the transformation of hydraulic constraints into the objective functions associated with a water supply network rehabilitation problem, a non-dominated sorting Genetic Algorithm-II (NSGA-II) can be used to solve the altered multi-objective optimization model. The introduction of NSGA-II into water supply network optimal rehabilitation problem solves the conflict between one fitness value of standard genetic algorithm (SGA) and multi-objectives of rehabilitation problem. And the uncertainties brought by using weight coefficients or punish functions in conventional methods are controlled. And also by in-troduction of artificial inducement mutation (AIM) operation, the convergence speed of population is accelerated;this operation not only improves the convergence speed, but also improves the rationality and feasibility of solutions.

Functionality analysis of an urban water supply network after strong earthquakes

An urban water supply network(WSN)is a crucial lifeline system that helps to maintain the normal functioning of modern society.However,the hydraulic analysis of a significantly damaged WSN that suffers from pipe breaks or leaks remains challenging.In this paper,a probability-based framework is proposed to assess the functionality of WSNs in the aftermath of powerful earthquakes.The serviceability of the WSN is quantified by using a comprehensive index that considers nodal water flow and nodal pressure.This index includes a coefficient that reflects the relative importance of these two parameters.The demand reduction(DR)method,which reduces the water flow of nodes while preventing the negative pressure of nodes,is proposed.The difference between the negative pressure elimination(NPE)method and the DR method is discussed by using the example of a WSN in a medium-sized city in China.The functionality values of the WSN are 0.76 and 0.99 when nodal pressure and nodal demands are used respectively as the index of system serviceability at an intensity level that would pertain to an earthquake considered to occur at a maximum level.When the intensity of ground motion is as high as 0.4 g,the DR method requires fewer samples than the NPE method to obtain accurate results.The NPE method eliminates most of the pipes,which may be unrealistic.

Optimal Dispatching of Large-scale Water Supply System

This paper deals with the use of optimal control techniques in large-scale water distribution networks. According to the network characteristics and actual state of the water supply system in China, the implicit model, which may be solved by utilizing the hierarchical optimization method, is established. In special, based on the analyses of the water supply system containing variable-speed pumps, a software tool has been developed successfully. The application of this model to the city of Shenyang (China) is compared to experiential strategy. The results of this study show that the developed model is a very promising optimization method to control the large-scale water supply systems.

Water Supply Network Losses in Jordan

Water supply network losses are an international problem especially in countries suffering from water scarcity like Jordan. Jordan is one of the poorest countries in its water resources and it is estimated to be below the water poverty line. Jordan is located in the Middle East and has a surface area of approximately 90,000 km2. Its population is around 6.3 million and it is estimated that the population will be 7.8 million in 2022. The gap between water supply and demand is widening due to development and a relatively high population growth rate. In addition, global climate change is expected to intensify the water shortage problem in Jordan. Thirteen years of complete records obtained from the Ministry of Water and Irrigation were analyzed. According to these records, water losses in Jordan reach about 50%. In view of the evaluation of the data and the case study conducted in this research, it is believed that Jordan can overcome the water shortage problem by adopting a water demand management strategy. In this context, efforts should be focused on reducing water losses. If this is achieved, it will save huge quantities of water and revenue.

Factors related to the functionality of community-based rural water supply and sanitation program in Indonesia

This study used multinomial logistic regression and Bayesian belief networks(BBN)to analyze factors influenc-ing the functionality of the community-based rural drinking water supply and sanitation program(PAMSIMAS)in Indonesia.28,936 PAMSIMAS projects in 33 provinces in Indonesia were analyzed.The data indicates that 85.4%of the water supply systems were fully functioning,9.1%were partially functioning,and 5.5%were not functioning.In the regression analysis,good management is positively associated with functionality and a high investment per capita is negatively associated with the functionality.The latter suggests the need for comprehen-sive economic analysis in the feasibility study in scattered housing sites and remote-undeveloped areas.We also found that high community participation at the beginning of the project was associated with the not functioning system,while women’s participation was positively associated with the functionality.Furthermore,the household connection is more likely to be functioning than communal connection.BBN analysis shows if the beneficiaries do not pay for water,the probability of not functioning systems is 20 times higher than systems with fee collec-tion.Moreover,the combination of strong management,strong financial status,and household connection rather than communal connection increases the probability of fully functioning to 98%.Improvement of data collection is also necessary to monitor the current conditions of all PAMSIMAS systems in Indonesia.This study offers a country-level perspective for better implementation of the community-based rural water supply and sanitation program in developing countries.

Analytic Hierarchy Process(AHP)to Optimize the Service in a Water Supply Network

Decision making in drinking water supply networks is increasingly complex due to the large number of variables involved.In order to make better decisions it is necessary to use adequate and robust methodologies.This paper presents the application of the Analytic Hierarchy Process(AHP)related to the operation of the drinking water supply network of the city of Chihuahua,Mexico,where two possible alternatives are delineated with the objective to optimize the service.The application of AHP was carried out in 24 sectors that have substantial differences in their efficiency but with instrumentation and measurement in all the variables contemplated by the operating agency,with a population of 221,722 inhabitants which represent a 30%of the total population of the city,the results indicate that the best alternative is the one with less criteria to be controlled and fewer repercussions on the cost of operation and investment in the rehabilitation and replacement of the network.

基于WSNs多参数水质监测的终端设计

针对传统水质监测系统不能对水质参数进行实时在线监测,难以准确检测水质参数的动态变化、水质参数检测误差大等问题,提出了基于无线传感器网络(WSNs)多参数水质监测的终端设计方案。采用模块化设计以满足个性化需要;采用太阳能和蓄电池双电源供电,以延长无线节点的工作时间。仿真测试结果显示:pH值、电导率、溶解氧的平均相对误差分别为2.21%,0.69%,2.05%,比传统的水质监测系统的精度提高了30%左右。

基于WSNs的城市绿地墒情监测硬件平台构建

针对北京城市绿地节水灌溉的需要,以CC2530无线射频芯片为核心,设计了基于无线传感器网络(WSNs)的低功耗终端数据采集节点和协调器,给出了节点硬件的低功耗设计思路,构建了绿地墒情监测硬件平台。实验结果显示:系统能够准确获得环境温度、土壤水分的数据。节点睡眠时的工作电流仅为10μA,节点实际平均工作电流仅为0.265 mA,功耗性能优于市场同类产品约30%。

基于WSNs的巢湖水质监测系统的设计

介绍了基于无线传感器网络(WSNs)的巢湖水质监测系统。通过Zig Bee无线技术与wifi、GPRS等通信技术对数据进行接收与远程通信,实现对水温、p H值、溶解氧、电导率、浊度等数据的定时采集、处理、远程存储、显示和实时分析并预警。并通过实验测试,取得实质性成果。

一种用于水质监测的WSNs节点的设计与实现

提出了一种基于无线传感器网络的水质监测传感节点设计方案,该节点由传感器模块、主处理器模块与无线通信模块和能量供应模块组成,其中传感器模块采用独立的模块结构,与主处理器之间由RS-485总线相连,主处理器与无线通信模块是以符合IEEE 802.15.4协议的CC2430芯片为基础设计的。多个传感器节点采用Zig Bee协议栈实现自组网,从而构建一个参数设置灵活、节点布置快速的水质自动监测系统。

基于WSNs的水环境云端监测系统研究

为了对水环境进行数据采集、传输和显示的全方位处理,设计了一套基于无线传感网(WSNs)的水环境云端监测系统,阐述了系统的网络架构及具体组成部分,包括终端监测节点、簇头节点、数据汇聚节点和基于Yeelink的远程监视中心,并详细介绍了各部分的软硬件设计。同时,支持用户在手机终端实时监测采集到的水温、压强、p H值等信息。通过实验和测试可以看出,该系统为低成本实时在线水质监测提供了一套可行的方案。

WSNs在水信息采集中的应用

针对传统的水信息获取方式多为人工观测、不适于恶劣的环境中使用这一问题,提出了使用无线传感器网络(W SNs)的节点设计思想。分析了系统的硬件设计方案和通信协议,并详细地讨论了传感器节点、汇聚节点、管理节点的设计方法,在MAC层协议设计上使用分时接收方法避免多节点发送数据时的冲突。实验测试结果表明:节点的功耗少,传输的距离约100m,数据的正确率高达99%以上,很好地满足了实际工程需要。

Reliability analysis of monotone coherent multi-state systems based on Bayesian networks

The Bayesian networks (BNs) provide a robust probabilistic method of reasoning under uncertainty and have been successfully applied to a variety of real-world tasks. Aiming to explore the capabilities of the BN formalism in reliability analysis of monotone coherent multi-state systems, the BNs are compared with a popular tool for reliability analysis of monotone coherent multi-state systems, namely the multi-state fault trees (MFTs). It is shown that any MFT can be directly mapped into BN and the basic inference techniques on the latter may be used to obtain classical parameters computed from the former (i.e. probability distribution of top variable, minimal upper vectors and maximum lower vectors for any performance level, importance measures of components). Furthermore, some additional information can be obtained by using BN, both at the modeling and analysis level. At the modeling level, several restrictive assumptions implicit in the MFT methodology can be removed and various kinds of dependencies among components can be accommodated. At the analysis level, a general diagnostic analysis can be performed. The comparison of these methods is illustrated by an example of the water supply system. © 2016 Beijing Institute of Aerospace Information.

Evaluation of Drinking Water Pollution and Health Effects in Baghdad, Iraq

Contamination of water reserves by biological, chemical, and radiologic agents may affect the health of millions of residents in the Iraq as well as many others throughout the world. Fatal outbreaks of cholera struck several provinces of the country, including Baghdad. The United Nations Environment Programme (UNEP) also says air pollution, resulting from burning oil and aggravated by war, is cause for concern. The study area Baghdad has been divided into two parts: Central Baghdad and Outskirts of Baghdad (included in Baghdad but near the boundaries of Baghdad). The outskirts of Baghdad comprises of 4 cities: Al-Hussaniya located in northern part of Baghdad, Abu-Gurabe located in the western side of Baghdad, Jissr Diyala located in the eastern side of Baghdad and finally Al-Mahmodiya located in the southern side of Baghdad. These cities are in very poor situation in terms of water supply. The quality of water supplied is bad as no attention is given to WTP's in these places, which is also because of the fact that given the insecure war conditions, these areas are inaccessible. The sewage is thrown directly into the river because these areas do not have sewage treatment plants. In case of central Baghdad the water supply and sewerage network are broken in some places. Due to this there is mixing of water between the two networks. For this study we taking water supply samples and collect all the samples from WTPs and water supply network (houses, shops and different places). We made the analysis to parts first bacteriologies, second chlorine and after analysis these samples in lab we will give in our study numbers of fail samples, type of diseases and how many case during year 2007 in Baghdad City. Also in this study we will give Estimated Deaths from Water-Related Diseases 2010 to 2035.

An Integrated Optimal Approach for Solar Powered Rural Water Distribution Systems in the Gambia

In the Gambia and across sub-Saharan Africa, reliable access to clean water and electrical power is constrained. As most rural water supply systems are built, enhanced understanding of efficiencies and optimisation is required. Here, methods of integrating estimations of power outputs from solar photovoltaic arrays into gravity-fed water distribution network modelling are investigated. The effects of powering a rural water distribution system that is replenished with groundwater pumps that use solar power are investigated, along with the effect of this on other network design decisions. The water storage tank and pipework of a rural community with an estimated 2800 people and 28 standpipes from a borehole was selected. EPANET modelling software and genetic algorithms were used to run network optimisation simulations of: water tank location, elevation and volume;pipe diameter and configuration;and optimal system design in terms of cost. Different scenarios were produced, including supply, demand and required water storage curves, which could have practical application for rural water distribution system design. Indicative costs for theoretical water distribution networks will be useful for decision makers and planners.

Algorithmic Procedure to Design Water Utilization Systems Featuring Multiple Contaminants in Process Plants

This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subject to no limitation on the problem scale.