Study On The The Impact Of Planning Central Yunnan Water Diversion Project On The Vegetation Of The Water Sources And Down Stream Terrestrial Ecological Evaluation Region

Central area of Yunnan province suffered from drought frequently in recent years. In order to solve this problem and satisfy the residents’basic water requirements, a water diversion project is planed, which will transfer water from the Jinsha River upper reaches-Benzilan area to central area of Yunnan province through water diversion channels. The Central Yunnan water diversion project’s water sources and down stream terrestrial ecological evaluation region is located in the Benzilan to Tiger-Leaping Gorge reaches of Jinsha River. The Benzilan water sources area lies on the boundary river of Diqing Tibetan autonomous region in Yunnan province and Ganzi Tibetan autonomous region in Sichuan province, about7.5kilometers away from Benzilan town. The down stream area includes the main stream and branches reaches in Jinsha River from the dam to Tiger-Leaping Gorge.Through interpreting the satellite images, as well as field vegetation survey and history data, this paper describe the current vegetation in this area. On the basis of that, with analyzing the features of the project, it forecasts the impacts which the project construction would produce to vegetation and presents the environmental protective measures. The results are as follows:the major vegetation types are coniferous forest and shrub grassland. Forest land and shrub land are the base land of the area. With the survey and remote sensing, this paper divides the natural vegetation into4vegetation type groups,6vegetation types,10vegetation subtypes,29formations, and artificial vegetation into2types. According to the features of different facilities in the project, this paper analyses the impacts of construction site, reservoir inundation, dynamic hydrologic regime, tunnels and other constructions, immigrant settlement and alien species invasion on the vegetation. Then, proposes the measures of prevention, reduction, recover, compensation and management. At last, this paper summerises the vegetation distribution in this area, and gives the next work suggestions from research and protection.