Water Allocation Research On Medium And Small River Basin

The goal of water resources allocation is to achieve a maximum balance between the supply and demand of water resources,and to obtain the maximum benefit or the minimum cost of water supply on the premise of improving the ecological environment,by reasonably suppressing the socio-economic and ecological water demand and appropriately expanding the water supply.At present,most of the water allocation methods and practices are focused on large basins,urban agglomerations,or large-scale basins/areas in provinces and cities.Their water allocation methods have problems such as poor adaptability and poor operability in small and medium-sized watersheds.The research of small and medium watersheds is equivalent to downscaling of large watersheds,causing contradictions and problems are locally amplified.The differences of large and medium-small watersheds are significant,the anisotropy is prominent,and the heterogeneity is increased.In the down-scaled study area,the level of water resources security is low,the ability to adjust storage capacity of the allocation project is low,the mutual compensation ability of various projects is poor,the water supply system is more fragile,and the degree of water shortage is sensitive.However,the data integrity is poor,the precision is low,and the previous research and work foundation is weak.Therefore,there is an urgent need to start with the scale of medium and small sized river basins,to study and develop a set of methods that are suitable for the allocation of water resources in medium and small river basins,and to provide an effective tool for solving the problem of water resources allocation in medium and small river basins.Based on the above considerations,relying on the "Water Resources Comprehensive Planning Project in Panshi City",taking small and medium-sized river basins as the research object.The water resources allocation methods of medium and small river basins are proposed by analyzing the conditions of water resources endowment in medium and small river basins,identification of water resources development and utilization problems,water demand and water availability analysis,and water resources allocation.The method is applied in Panshi City,a county-level administrative region of Jilin City.The main conclusions include:(1)Based on the concept of medium and small river basins,this paper analyzes the basic features of medium and small watersheds,and gives the differences in water resources and their development and utilization surveys,future water demand and water availability analysis,and water resource allocation between large river basins and medium-sized river basins.It including different scale basins.Characteristics and differences,and some problems faced by the allocation of water resources in small and medium-sized river basins.(2)Aiming at the characteristics and some problems of water resources allocation in middle and small river basins,the water resources allocation methods for medium and small river basins are studied and proposed,including:1)Water resources survey and evaluation methods in the absence of data;2)Calculation of water resources development and utilization and identification of existing problems;3)The quantification method of the definition of water requirement caliber and development index;4)Calculation of available water quantity;5)Construction and solution of water resource optimization configuration model based on characteristics of medium and small river basins.(3)Choose Panshi city,a county-level administrative district of Jilin City,as the example of water resources allocation method for small and medium-sized river basins.In view of the characteristics of small-scale projects of small and medium-sized watersheds in the area under the jurisdiction of Panshi City,weak capacity for water storage,low water resources development rate,and low water resources availability,the monthly adjustments and comparisons of different series of different levels of seniority are conducted.Analyze and give the result of water allocation of the recommended scheme and sub-optimal recommendation scheme.The recommended scheme considers the construction of a project of diverting water from the Songhua River into Panshi city.In 2030,the Annual average water demand will be 255.64 million m3,and Annual average water supply will be 252.96 million m3,and the water shortage rate is 1.0%;The sub-optimal recommendation scheme does not consider the water transfer projects and chooses low water requirements.In 2030,the average water requirement for many years will be 238.36 million m3.The average annual water supply will be 228.19 million m3,and the water shortage rate will be 3.0%(mainly in the urban area and Hongqiling Town).