Assessment Of The Ecological Environment Impact Of Water Diversion Tunnel Passing Through Nature Reserves

Due to the uneven distribution of water resources,there are many cross-basin water transfer construction projects in my country,and the construction mileage of water transfer tunnels is also increasing.More and more water transfer tunnel projects inevitably need to pass through nature reserves.The environment has many impacts.Therefore,it is necessary to evaluate the impact of water tunnels through nature reserves on their ecological environment.This paper analyzes the ecological environment impact characteristics of the water diversion tunnel and the ecological protection requirements of the nature reserve,firstly discusses the ecological environment impact assessment method,and then establishes the evaluation index system of the water diversion tunnel crossing the nature reserve on its ecological environment.As an example,the tunnel passed through the Wudaoxia Nature Reserve in Hubei,and the ecological environment impact assessment was carried out.Mainly obtained the following research results:(1)According to the access principles of nature reserve construction projects and relevant laws and regulations,and at the same time analyze the environmental impact characteristics of the water diversion tunnel,provide a basis for the ecological environment impact assessment of the water diversion tunnel passing through the nature reserve.(2)Scientifically select indicators and establish an index system for evaluating the impact of water tunnels on the ecological environment of the nature reserve.The indicator system includes two categories: biological system influence and non-biological system influence.Among them,there are 3 indicators for biological system influence,and 16 indicators for non-biological system in 6 sub-categories.(3)An on-site investigation was conducted on the ecological environment impact assessment area of the Wudaoxia Nature Reserve through the water diversion tunnel.In the assessment area,there are 432 species of 297 genera and 119 families of vascular plants,including 41 species of pteridophytes,19 families,27 genera,4 families,6 genera and 7species of gymnosperms,and 384 species of 264 genera and 96 families of angiosperms.There is only one species of wild soybean that is a national key protected wild plant.The types of natural vegetation communities are divided into 3 vegetation type groups,3vegetation types,and 7 formations.The types of artificial vegetation communities can be divided into two communities.There are 70 species of wild animals distributed in 39 families,including 1 species of national key protected wild animals and 30 species of key protected wild animals of Hubei Province.(4)Through comparative analysis,the method of combining the analytic hierarchy process and the fuzzy evaluation method is used to evaluate the impact of the water diversion tunnel through the Wudaoxia Nature Reserve on the ecological environment.The comprehensive impact value is 0.3944,which is judged to be a mild impact.Among them,the biological system impact evaluation value is 0.0307,accounting for 7.78% of the total score,and the non-biological system impact evaluation value is 0.3637,accounting for 92.22% of the total score.In comparison,the water diversion tunnel project has minimal impact on the biological system of the protected area,and greater impact on the non-biological system,especially the ecological environment effect of the groundwater level in the protected area.(5)In order to reduce the impact of the water diversion tunnel crossing the Wudaoxia Nature Reserve on the ecological environment,environmental management and monitoring suggestions were put forward during the engineering exploration,construction and operation periods.