Study On Leakage Assessment And Control Of Urban Water Supply Networks For Water Supply Companies

The shortage of water resources is becoming more and more serious with the acceleration of urbanization.The leakage of water supply networks is one of the main reasons for the low utilization rate of water resources in cities and towns in my country.The single leakage rate indicator currently adopted by the Ministry of Housing and Urban-Rural Development cannot fully assess the water supply networks leakage situation in terms of active leakage control,water supply networks facility renovation and transformation,and unit leakage.Therefore,the study a new comprehensive evaluation index system has been established and how to control leakage damage has been highlighted in this article.This study combines the water supply service performance indicators of the International Water Association and applies them to the analysis and improvement of the leakage indicators of the Ministry of Housing and Urban-Rural Development,and establishes a comprehensive assessment system for water network leakage.Based on the water balance theory,the water volume of each component in the main urban area of a city in the south of the Yangtze River is analyzed.The feasible control method of leakage for urban water supply networks is studied,which provides technical support and method reference for assessment and management of urban pipeline network leakage.First of all,the study aims at the current operating status of Chinese urban water supply system,combined with the six water service performance indicators recommended by the International Water Association,and establishes two indicators that are divided into leakage prevention indicators and water leakage indicators,and are highly applicable to Chinese cities and towns.Two-class-three-level-twelve-index tree-shaped pipe network leakage assessment system.The tree-shaped comprehensive evaluation system consists of 2 first-level indicators,4 second-level indicators,and 12 third-level indicators.Based on the water balance theory and engineering experience,this article summarizes the calculation methods of 12 indicators.The tree-shaped pipe network leakage assessment system established by the research provides a new way to promote the comprehensive leakage assessment of the pipe network of urban water supply companies.Secondly,after establishing a comprehensive leakage assessment system,this article takes a city in the south of the Yangtze River as an example,analyzes the water composition of each component in the study area from 2018 to 2019 according to the water balance method,and applies the comprehensive leakage assessment system Evaluation.After calculation,the leakage rate of the study area in 2018 and 2019 was 11.51% and 10.63%respectively.The analysis also indicates the the relationship between the leakage of the water supply networks and the pipe materials,pipe diameters etc.The smaller the pipe diameter,the greater the probability of the leakage accident;the galvanized pipe has the highest probability of the leakage accident.The index calculation results confirmed the key role of concealed leak detection in physical leakage control,and indirectly confirmed the importance of DMA concealed leak management.Finally,a study on the application of DMA management to the leakage control of urban water supply networks and an analysis of the three DMA leakage evaluation methods were conducted.Taking two independent metering management communities in the study area as an example,In 2019,a pilot test for detection and repair of dark leaks was carried out,which demonstrated the feasibility of DMA management and control of leaks.After the independent metering area management in the study area,the average daily minimum night-time flow value in 2019 decreased by 5.4% compared with 2018,and it is gradually decreasing.Aiming at the operation mode of leakage control of the water supply networks,a long-term assessment and management mechanism based on the results of leakage control is proposed.