Research On Ecological Rehabilitation Model And Technology Of Eco-clean Small Watershed In Hubei Water Source Area Of South-to-north Water Diversion Middle Route Project

As the water source area of the South-to-North Water Diversion Middle Route Project,the Danjiangkou Reservoir area and its upper area have a large pollution risk in recent years,due to the serious point source pollution,increasingly prominent non-point source pollution,and the existence of potential pollution risk sources.In order to ensure the safety of the water environment in the Danjiangkou water source area and the smooth implementation of the South-to-North Water Transfer Project,a series of small watershed management projects have been carried out,and a large number of ecological restoration engineering technologies have been developed.However,due to the lack of unified layout and overall planning of existing engineering technologies,the overall governance effect is not obvious and the sustainability is poor,which is difficult to meet the needs of small watershed ecological restoration projects.Therefore,this paper takes the Hubei Water Source Area of South-to-North Water Diversion Middle Route Project(hereinafter referred to as’Hubei water source area’)as the research area.On the basis of field research,focusing on the ecological and environmental problems,considering all kinds of landscape elements of mountains,rivers,forests,farmland and lakes,put forward to the ecological restoration engineering technology system of small watersheds that can be popularized and applied in Hubei water source area,explore new methods of restoring and improving ecological environment of river basin in order to guide the construction of eco-clean small watersheds the South-to-North Water Diversion Middle Route Project,at the same time provide technical support for eco-clean small watershed construction work in southern hilly and mountainous region.The work and main research conclusions are as follows:(1)Taking Hubei water source area as the research area,from the perspective of improving the ecosystem service function,the optimal confluence area threshold of the eco-clean small watershed is set to 30km~2,and the study area is divided into 482eco-clean small watershedss.According to the ecological restoration goals,the eco-clean small watersheds are divided into three types:ecological agriculture,urban development,and ecological conservation,and the spatial distribution patterns of different types of eco-clean small watersheds are obtained.(2)Select different types of typical ecologically eco-clean small watershed construction projects in Hubei water source areas to conduct field investigations,take Hujiashan,Shuangtang River and Qingshui River eco-clean small watersheds as examples to analyze the ecological environment status and existing problems of different types of ecologically clean small watersheds.Combined with literature analysis and GIS spatial analysis,the ecological environment problems of different types of eco-clean small watersheds are summarized,and the focus of restoration of different types of eco-clean small watersheds is finally determined.(3)Determine the ecological restoration goals of different types of eco-clean small watersheds according to the focus of ecological restoration,and propose 6 ecological restoration models and 21 combined ecological restoration technologies,thereby constructing different types of eco-clean small watersheds ecological restoration models and technical systems in Hubei water source area.