Study On The Problems Of The Planning Of Urban Water Supply

With the rapid development of China’s social economy and the continuous improve-ment of urbanization level,it become more serious for water shortage、water quality deterioration and sudden water pollution incidents and other issues.So there is new requirements for the development of urban water supply.Therefore,in order to solve the current situation of water supply preferably,use of water resources rationally,optimize water supply and water quality,it’s very important to work out a scientific and rational water supply planning.However,there are some question for the existing water supply planning,so this article will do a detailed analysis for the existing problems of urban water supply planning,and putting forward the corresponding solution for water demand forecast,pipe network layout and water-saving planning which is the most important three aspects of the existing problems,and providing a reference for the subsequent urban water supply planning.For the large error of water demand forecast by ‘index prediction method’,the paper puts forward the basic idea of “forecasting by means of ‘index prediction method’,and supplementing with the mathematical model method”.Selecting several water demand forecasting methods(Annual growth rate method,regression analysis method,moving average method,exponential smoothing method and grey forecasting method),and verifying the accuracy and applicability of the model with the highest daily and annual water consumption data from 2000 to 2015 in Guiyang.Finally,evaluating and selecting these forecasting methods.For the problem of pipe network layout in the existing water supply project,this paper puts forward the optimal layout of the water supply pipe network based on the "Distribution Blocking System",and introducing the method and basis of the partitioning of the pipe network in detail.And simulating the number and location of water entry of each water supply area with EPANET 2.0 software.In the end,the paper contrastively analyse the effect of the partitioning and non-partitioning by detailed cases in this aspects of the water pressure,water quality,pipe network leakage and the investment of the pipe network.For the problem of water-saving goal setting,this paper puts forward the optimization model of water-saving quanity allocation of water-using subsystem based on economic investment and the optimization model of unconventional water supply construction cost,and establishing the constraint based on the "water-saving city" assessment index.In the end,optimizing the water-saving goal of the planing period and finding a water-saving goal which is in line with the water saving city assessment and make the optimal investment in the construction,and providing some reference for the preparation of the water-saving part of the water supply planning.At last,taking the urban water-saving target of Banan District in Chongqing as an example,the model is applied practically,There are still many other problems to be studied in the redaction of the water supply planning.This paper has not been solved because of the length of space.In this study,there are still some shortcomings,such as the verification of several water demand forecasting methods.And the applicability of other forecasting methods can not give the corresponding assessment.For distribution blocking system theory,there is no mathematical model for the partition,the regional size of the partition is not quantitatively analyzed;For the redaction of water-saving,water-saving measures are not analyzed.