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.

Developing and introducing of the resourcesaving technologies into the water-supply systems of mining enterprises

The article deals with modeling the tailing ponds influence on water resources. New technology using hydrocyclons of new design has been offered for additional purification of gold dressing mill wastewater. Laboratory and plant test have determined the optimal parameters of hydrocyclon. Introduction of new technology into system of water supply will prevent environment pollution and make it possible to process recoverable resources.

Optimal operation of water supply systems with tanks based on genetic algorithm

In view of the poor water supply system’s network properties, the system’s complicated network hydraulic equations were replaced by macroscopic nodal pressure model and the model of relationship between supply flow and water source head. By using pump-station pressure head and initial tank water levels as decision variables, the model of optimal allocation of water supply between pump-sources was developed. Genetic algorithm was introduced to deal with the model of optimal allocation of water supply. Methods for handling each constraint condition were put forward, and overcome the shortcoming such as premature convergence of genetic algorithm; a solving method was brought forward in which genetic algorithm was combined with simulated annealing technology and self-adaptive crossover and mutation probabilities were adopted. An application example showed the feasibility of this algorithm.

Evaluation and optimization of secondary water supply system renovation

Due to pollution in second water supply system (SWSS),nine renovation alternative plans were proposed and com-prehensive evaluations of different plan based on Analytical Hierarchy Process (AHP) were presented in this paper. Comparisons of advantages and disadvantages among the plans of SWSS renovations provided solid foundation for selecting the most appro-priate plan for engineering projects. In addition,a mathematical model of the optimal combination of renovation plans has been set up and software Lingo was used to solve the model. As a case study,the paper analyzed 15 buildings in Tianjin City. After simulation of the SWSS renovation system,an optimal scheme was obtained,the result of which indicates that 10 out of those 15 buildings need be renovated in priority. The renovation plans selected for each building are the ones ranked higher in the com-prehensive analysis. The analysis revealed that the optimal scheme,compared with two other randomly calculated ones,increased the percentage of service population by 19.6% and 13.6% respectively,which significantly improved social and economical benefits.

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.

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.

Method of Distinguishing Hydrologic Drought for Water Supply System

It is very common to design water supply system to adjust runoff. Thus it will not meet the practical needs if only the hydrologic drought in natural basin is studied. In practice the natural water balance and water deficits must be researched, i. e. . the adjusting effects of the water supply sys- tem such as a reservoir should be considered, and the drought event be distinguished according to the special system. The problem of drought identification under adjusted runoff was investigated in this study. By considering water transfer during different periods, a method to distinguish hydrologic drought for the water supply system was developed, and a standard drought severity index SWDSI was proposed. The method has been applied in Pan Jiakou water supply system in China. From 1953 to 1997,a total of 14 hydrologic droughts were identified in the water supply system, among which there were 3 severe droughts, 6 moderate droughts and 5 light droughts. The results are in good agreement with the historic drought records.

Drinking water quality & health risk assessment of secondary water supply systems in residential neighborhoods

Secondary water supply systems(SWSSs)are important components of the water supply infrastructure that ensure residents’drinking water safety.SWSSs are characterized by long detention time,warm temperature,and unreasonable management,which may trigger the deterioration of water quality and increase risks.In this study,drinking water quality index(DWQI)and health risk assessment(HRA)were selected and modified to quantitatively assess the water quality and health risks of SWSSs in residential neighborhoods.In total,121 seasonal water samples were selected.It was observed that the water quality was excellent with the DWQI of 0.14±0.04,excluding one sample,which was extremely poor owing to its excessive total bacterial count.The HRA results revealed that the health risks were low:negligible non-carcinogenic risk for any population;negligible and acceptable carcinogenic risk for children aged 6–17 and adults.However,samples revealed higher carcinogenic risk(7.63×10−5±3.29×10−6)for children aged 0–5,and arsenic was the major substance.Summer samples had poor water quality and higher health risks,which called for attention.To further investigate the water quality and health risks of SWSSs,monthly sampling was conducted during summer.All 24 water samples were qualified in Chinese standard(GB 5749-2022)and characterized as excellent quality.Their HRA results were consistent with the seasonal samples’and the health risks were mainly concentrated in May.Overall,our study provides a suitable framework for water quality security,advice for managers,and references for administrators in other cities.

Behaviour of Haloacetic Acids in Drinking Water Distribution Systems

To guarantee the safety of drinking water quality after chlorination,the formation,distribution and factors influencing the concentrations of haloacetic acids(HAAs)in a water distribution system(WDS) were investigated both on a full-scale WDS(FWDS) and pilot-scale WDS(PWDS) within a city in northern China.The results of both investigations showed that trichloroacetic acid(TCAA) and dichloroacetic acid(DCAA) were the dominating types of HAAs.In the FWDS,variations in the HAA content showed negative correlations with total residual chlorine,pH and non-purgeable organic carbon(NPOC)and positive correlations with temperature and UV_(254).In the PWDS,the concentration of HAAs after rechlorination followed the rule of 'first rise and then fall';therefore,locating an appropriate rechlorination point and lowering the single chlorine dosage could be used as effective measures to control the HAA content in WDSs.

Synthetic Reconstruction of Water Demand Time Series for Real Time Demand Forecasting

The forecasting of the demand applied to water supply systems has been an important tool to realize time control. The use of the time series to do the forecasting of the demand is the main way that has been used by researchers. By this way, the need of a complete time demand series increases. This work presents two ways to reconstruct the water demand time series synthetically, using the Average Reconstruction Method and Fourier Method. Both the methods were considered interesting to do the synthetic reconstruction and able to complete the time series, but the Fourier Method showed better results and a better fitness to approximation of the water consumption pattern.

基于KingWater全组态平台在供水智能调度系统的开发与应用

结合供水企业实际需求案例,从优化调度以及智能控制两个方面对城市的供水系统进行了详细地分析和介绍,并针对如何实现智能化控制,降低企业运营成本,缩短系统开发周期,降低开发运维成本,使项目快速落地。通过采用面向工程师的全组态开发平台KingWater,快速完成供水智能调度系统及信息化系统的开发、部署与应用,开发运行效果表明:所开发的系统具有较好的易用性、可靠性和可扩展性并能高效实现随需而变。

Geographic Information System Application for Water Supply System:A Case Study in Paphos,Cyprus

Geographic Information Systems(GIS) can be successfully introduced as a tool to manage water system infrastructures.This technology was taken into consideration after the local authorities’ estimation for almost 30%losses in the water distribution networks in cities.The major issue of water shortage in

Watershed management for water supply in developing world city

The water supply system in Shanghai provides about 2.55×109 m3/a,of which more than 50% is derived from the Upper Huangpu River Watershed. During the process of rapid urbanization and industrialization,the role of watershed management in sustaining clean drinking water quality at surface sources is emphasized in Shanghai. This paper proposes an integrated watershed management (IWM) approach in the context of the current pressures and problems of source water protection at the Upper Huangpu River Watershed in Shanghai. Based on data sets of land use,water quality and regional development,multi-criteria analysis and system dynamics techniques were used to evaluate effectiveness and improve decision-making of source water protection at a watershed scale. Different scenarios for potential source water quality changing from 2008 to 2020 were predicted,based on a systematic analysis and system dynamics modeling,a watershed management approach integrating land use prioritization and stakeholder involvement was designed to conserve the source water quality. The integrated watershed management (IWM) approach may help local authorities better understand and address the complex source water system,and develop improved safe drinking water strategies to better balance urban expansion and source water protection.

Development of a Strategic Planning Model for a Municipal Water Supply Scheme Using System Dynamics

This paper reports the development of a system dynamics model for the strategic planning of a municipal water supply scheme. The model is capable of handling the critical variables that impact on the operations of a water supply scheme. The model was developed using the dynamo programming software to handle the process dynamics. Other supporting softwares—Fortran, Clipper 5, and Epiglue are used to handle data input, analysis and presentation of results in a user-friendly environment. The model was validated by applying it to the simulation of the University of Ibadan Water Supply Scheme for which extensive data of operations were collected over a period of ten years. The results obtained were found to be realistic and useful for the planning of plant operations. It is concluded that the model developed is sensitive to variable changes and has the capability of answering various operational “what-if” questions. As a strategic planning tool, the present model generates, for different scenarios, important operational information for the management of the water supply scheme. It is concluded that SD model is a useful tool to assist water managers and policy makers in making decisions and evolving strategic planning for water supply.

Operating Rule Classification System of Water Supply Reservoir Based on Learning Classifier System

An operating rule classification system based on learning classifier system （LCS）, which learns through credit assignment （bucket brigade algorithm, BBA） and rule discovery （genetic algorithm, GA）, is established to extract water-supply reservoir operating rules. The proposed system acquires an online identification rate of 95% for training samples and an offline rate of 85% for testing samples in a case study. The performances of the rule classification system are discussed from the rationality of the obtained rules, the impact of training samples on rule extraction, and a comparison between the rule classification system and the artificial neural network （ANN）. The results indicate that the LCS is feasible and effective for the system to obtain the reservoir supply operating rules.

Complex Sequence Quality Evaluation Model for Concealed Water Supply Pipeline of Prefabricated Construction

The accurate assessment of the quality can materially affect the safety and life of the prefabricated construction.In this paper,we studied the overall module of concealed water supply pipeline,and a new complex sequence quality evaluation model was established.By analyzing the small evaluation index elements of the model,the weight of the larger evaluation index could be deduced.The total quality evaluation score of the overall module could be obtained by calculating the weight value of the evaluation index,and then the quality standard of the overall module could be obtained.

WaterCAD软件在供水系统管网平差中的应用

WaterCAD软件可对供水管网系统进行静态与动态模拟分析和设计,能够快速、便捷地为用户产生各种图表、曲线和报告。利用WaterCAD软件对寿光市城区供水管网进行平差计算,以不同颜色表示节点压力、节点流量、管段管径、管长、流速、流量等各项信息,使供水管网系统化、图形化和直观化。采用此软件,可以保障供水系统的安全,提高供水系统的自动化水平。