Utilization Evaluation And Regulation Mechanism Of Water Resources Safety In Three Gorges Reservoir Area (Chongqing Section)

The special geographical location of the Three Gorges reservoir area determines the sensitive area of the national ecological environment protection,the ecological environment construction in the Three Gorges reservoir area is the key to the water quality safety of the Yangtze River Basin.It is an important prerequisite to ensure the ecological security of the reservoir area,which is clear that the spatial and temporal differentiation and evolution trend of water resources security in the Three Gorges reservoir area.With the construction of the Three Gorges Project,the problems existing in the water resources and ecological environment protection of the Three Gorges reservoir area have become increasingly prominent.The development of social economy leads to the increase of domestic sewage and industrial sewage,the range and degree of agricultural non-point source pollution is increasing.Therefore,it is necessary to establish a scientific evaluation index system and evaluation model of water resources safety utilization for the characteristics of the Three Gorges reservoir area to find out the areas with more serious water resources safety and make clear the stress factors and major bottlenecks affecting the safe use of water resources.It is of great theoretical and practical significance to promote the protection of water resources in the Three Gorges reservoir area and realize the sustainable development of water resources and socio-economy.In order to secure the use of water resources more objective comprehensive evaluation,combined with the machine learning algorithm of autonomous learning,R language to construct the evaluation model of water resources utilization in Three Gorges Reservoir area of Chongqing were selected based on BP neural network,construct RF(random forest)model were compared,and combined with the previous research results were compared to verify,confirm the feasibility of the evaluation method.At the same time,through the visualization of GIS technology,analyzed the three gorges reservoir area of chongqing water security by using the space change and the future development trend,to clear its limiting factors,the specific conclusions are as follows:(1)Based on the connotation and theoretical framework of water resources security,this paper chooses 21 index factors from four aspects: water resources economic security,social security,ecological security and supply and demand security,with reference to the evaluation index system of water resources safety utilization at home and abroad,constructs the evaluation index system of water resources security in Chongqing by a set of relatively complete and independent the Three Gorges Reservoir area,and according to the evaluation standard,to determine the threshold of each index in the evaluation grade.(2)The three-layer BP neural network model was used to evaluate the water resources safety of the study area in 2014.The RF model and the related research results were validated.Shapingba and Jiangbei Districts are the basically safe areas.Through the evaluation of the subsystems,it is concluded that the safety of the water resources in the districts and counties,such as the economic safety of the county in Wuxi and the social security of the main urban areas,is the main factor restricting the safe use of water resources in the region and regulation.(3)By choosing the water security data of the three gorges reservoir area in 2000-2014,the BP neural network is employed to construct an evaluation mode of safe utilization of water resources.Then,index prediction in combination with an ARIMA model is performed to analyze the temporal and spatial differences of security utilization of water resources in Chongqing section of the Three Gorges Reservoir area.The results show that in the past 15 years,the ecological security of water resources in the study area is the main reverse force that restricts the safe use of water resources to the safer,and the supply and demand is the second.The results of water resources safety evaluation in 2015-2020 show that the safety of water supply and demand in the study area is the main factor that restricts the overall improvement of water resources.The ecological security is the second,and the control and regulation of these two aspects should be emphasized.(4)By combining the importance function of RF model,the importance index of water resources safety evaluation index of Chongqing section of Three Gorges Reservoir area is obtained,and the emphasis on water resources regulation and control is found,that is,the water consumption and the proportion of ecological water are reduced.Clear the future of water resources safety control of the main focus,namely,ecological security subsystem and supply-demand safety subsystem.