The Change Of Ecosystem Health Level And Driving Factors In Xiangjiang Changsha Comprehensive Hub Reservoir Area

The water conservancy projects have hindered the continuity of the river to some extent,changed the river capacity,river water level and velocity,affected by human activities,the water ecosystem is more sensitive.The Xiangjiang Changsha comprehensive hub project has brought a series of environmental,economic and social benefits to the Changsha Zhuzhou Xiangtan Urban Agglomeration,and also brought some negative effects.The health of the water ecosystem health directly affects the human health and the sustainable development of the social economy.Therefore,Reach on the change of ecosystem health level and driving factors in Xiangjiang Changsha comprehensive hub reservoir area,which is of great significance to the protection and development of water resources in Changsha Zhuzhou Xiangtan Urban Agglomeration,the improvement of water environment quality and the establishment of "two-oriented society"(resource-conserving&environmental-friendly society).This research is based on the reality of the reservoir area and establishing index system of PSR framework model to analyze the temporal and spatial variation of the ecosystem health level in the reservoir area and at the same time to discusses the driving mechanism of the changes in the ecosystem health level,and proposes the improvement of the ecosystem health level on this basis.1.Selecting 2006,2009 and 2010 as the typical year before storage in the reservoir area,and 2011,2014 and 2016 stands the typical year after storage in the reservoir area,then the entropy weight method combined with TOPSIS method was used to evaluate the ecosystem health level in the reservoir area.Reach shows that? In 2006-2016,the overall ecosystem health level of Xiangjiang Changsha comprehensive hub reservoir area score was fluctuating upward trend,increased from 0.2697 to 0.4968.The level of health increased from grade ?(sub-morbid)to grade?(critical),and the ecosystem health level was obviously improved.? The ecosystem health level of the stress subsystem was reduced from grade ?(critical)to grade ?(critical)or grade ?(sub-morbid),and tress increased;The ecosystem health level of the state subsystem is from grade ?(sub-morbid)raising to grade ?(critical);The ecosystem health level of the response subsystem is from grade IV(sub-morbid)or grade ?(critical)raising to class ?(sub-health).? From the analysis of the spatial dimension,Changsha reservoir,Xiangtan reservoir,Zhuzhou reservoir ecosystem health level score showed a rising trend,the ecosystem health grade all all from level ?(sub-morbid)rise to ?(critical),ecosystem health level increased significantly,and the Zhuzhou reservoir area(0.5274)>Xiangtan reservoir area>(0.5137)>Changsha reservoir(0.5001).2.The main influence factors of the ecosystem health level in the reservoir area are analyzed by using the unitary linear regression model and the quantity chart,research shows that the main factors affecting the ecosystem health level in the reservoir area includes population density,the level of urbanization,water resources development and utilization,management level of ecosystem in the reservoir area,the investment of environmental protection management accounted for the proportion of GDP,GDP unit water consumption,urban sewage treatment rate,runoff and average per capita water resources.The main driving mechanism of the ecosystem health changes in the reservoir area is the environmental protection mechanism,the water and sediment mechanism,the social economic mechanism and the management system mechanism.3.In order to promote the healthy development of the ecosystem in the reservoir area,the suggestion of improving the health level of the ecosystem is put forward in combination with the reality of the reservoir area.It includes the proactive role of the construction of the reservoir area;Organize and coordinate multi power,and enhance the ecosystem health in reservoir area;To realize the innovation of the ecological management mode and establish an effective protection mechanism.