Research On Optimal Allocation Of Water Resources In Yizheng City Based On Multi-objective And Multi-source

Water is the fundamental resource for all development.The optimized allocation of water resources is beneficial for improving the efficiency of water resource utilization and alleviating the contradiction between supply and demand.The water resources in Yizheng City are complex,with the Yangtze River and Huai River watershed passing through the area.The southern part belongs to the Yangtze River Basin and the northern part belongs to the Huai River Basin,resulting in uneven spatial distribution of water resources;Water resources mainly come from precipitation,with uneven distribution of precipitation time and weak water resource regulation and storage capacity.Fully utilizing the existing water allocation system and cross basin water replenishment lines in Yizheng City,unifying the scheduling of water storage and diversion projects,comprehensively considering economic,social,and ecological benefits,and reasonably allocating various water sources are conducive to promoting the high-quality development of Yizheng City.This article takes Yizheng City as the research object.Based on the analysis of water resources and their development and utilization characteristics in Yizheng City,and based on the water resource bulletin and water resource investigation and evaluation report data,it explores the use of BP neural network for water demand prediction,analyzes the corresponding relationship between water demand and water supply frequency in the research area,and selects appropriate representative years.Based on this,it conducts water resource allocation research for planning level years,Utilize the constructed multi-objective and multi water source planning model to optimize the allocation of water resources in Yizheng City.The specific work content and achievements of this article are as follows:(1)Establish a BP neural network for water demand prediction and predict the water demand in Yizheng City.Collect historical data on social economy and water use,establish a water demand prediction BP neural network based on the actual water use situation in Yizheng City,and predict the water demand in the planning level years 2025 and 2030.By comparing and analyzing the prediction results with the traditional prediction method quota method,it is found that the two methods have significant differences in the prediction results of agricultural water demand and industrial water demand.Furthermore,predict the water demand in the planning level years at different local water frequency.(2)Study the correspondence between water demand and water supply frequency in Yizheng City and select an appropriate representative year.A simulation calculation model for the relationship between irrigation water demand and precipitation of rice was established based on the principle of water balance.The temporal variation characteristics of annual rainfall,flood season rainfall,net rainfall,and irrigation water demand in the study area were analyzed.The quantitative relationship between irrigation water demand and annual rainfall was calculated,and the differences in representative years selected based on different factors were compared.The corresponding frequency relationship was analyzed.The conclusion is that the frequency relationship between different influencing factors is complex and variable,An objective method was proposed to determine the representative year by minimizing the selection coefficient,and a formula for calculating the selection coefficient was constructed.The selection coefficient was applied in the research area to select a relatively reasonable representative year that comprehensively considers water supply and demand.(3)Research on the optimal allocation of water resources in Yizheng City using a multi-objective and multi-source planning model.Build a multi-objective multi water source planning model with economic,social,and ecological benefits as the objectives,and determine the detailed parameters of the model based on the supply and demand water volume of different water inflow situations.With the goals of minimizing regional water shortage,maximizing gross domestic product,and minimizing pollutant emissions,the model is solved using a fast non dominated genetic algorithm with elite strategy(NSGA-Ⅱ),Obtain water resource allocation plans for different inflow conditions in the planning level year.According to the water resource allocation plan,there is a certain degree of water shortage in ecological water,industrial water,and agricultural water in 2025 and 2030 when the local water inflow frequency is 90%.When the frequency of local incoming water is constant,the utilization rate and water supply rate of transit water decrease with the increase of its own incoming water frequency,while the utilization rate and water supply rate of local surface water increase with the increase of incoming water frequency;When the frequency of incoming water in transit is constant,the utilization rate and supply rate of available water supply in transit both increase with the increase of local water frequency.The utilization rate of available water supply in local surface water increases with the increase of self incoming water frequency,while the supply rate of local surface water decreases with the increase of self incoming water frequency.