Study On Water Environment Carrying Capacity In Henan Province Based On Three Evaluation Models

Since the 18 th national congress of the communist party of China,China has made vigorously strengthening ecological environmental protection and promoting ecological progress to the top priorities in building a moderately prosperous society in all respects.Therefore,more attention has been paid to the carrying capacity of the water environment.The research on the carrying capacity of water environment will help to rationally evaluate the carrying capacity of regional water environment.Furthermore,it provides theoretical support and reference for the decision-making process of regional industrial structure adjustment and rational allocation of water resources,so as to better promote the sustainable development of water environment,water resources,ecological environment and social economy.This paper selected Henan province as the research area,and combined with its current situation of natural environment and social and economic development,an evaluation index system of WECC in Henan province is constructed,which includes 3 subsystems and20 evaluation indexes.Based on this system,three evaluation models of fuzzy synthesis,principal component analysis and BP neural network were used to evaluate the carrying capacity of water environment in Henan province from two dimensions of time and spatial.At the same time,the spatial visualization function of ArcGis is used to show the characteristics of water environment carrying capacity in different regions of Henan province.The results show that the carrying capacity of water environment in Henan province is on the rising tendency from 2013 to 2018,indicating that water environment and social economy are developing in a good direction.Based on the fuzzy comprehensive evaluation model and the BP neural network model,the mean value of the water environment carrying capacity of Henan province in recent six years is 0.6010 and 0.5711,indicating that the water environment carrying capacity of Henan province is still at a medium level,and the water environment and water resources are still in a relatively uncoordinated state with the development of human society and economy.The fuzzy comprehensive evaluation model was used to evaluate and analyze each subsystem of water environment carrying capacity,and the mean value of comprehensive evaluation of water resource subsystem was 0.4352,which was in the poor bearing range of level IV.The mean value of comprehensive evaluation of water ecological environment subsystem is 0.7894,which is in the better bearing range of levelII.The mean value of comprehensive evaluation of socio-economic subsystem is 0.5824,which is in the middle bearing range of level III.Obviously,the water resources system is the main factor that leads to the insufficient carrying capacity of water environment in Henan province.The water environment carrying capacity of Henan province shows a decreasing trend from southwest to northeast under the spatial dimension.Through research and analysis,the main reason lies in the uneven spatial distribution of population size and natural resources.Xinyang,Nanyang and Luoyang have the most outstanding water environment carrying capacity in the whole province,while Zhengzhou,the provincial capital,is at the middle level.The research results of WECC in Henan province based on three different evaluation models will have positive guiding significance for the formulation of countermeasures to improve water environment carrying capacity.