Evaluation on Ecological Vulnerability of the Vegetation in the Subei Lake Watershed Based on Analytic Hierarchy Process

[ Objective] The research aimed to evaluate ecological vulnerability of the vegetation in the Subei Lake watershed based on analytic hierarchy process （AHP）. [ Method] From actual situation of the vegetation ecology in the Subei Lake watershed, by the established evaluation index system of vegetation ecology, based on AHP, indicator weight at each layer was determined. Comprehensive index method was used to calculate ecological fragility degree of the vegetation in each evaluation unit to evaluate ecological vulnerability of the vegetation. [ Result] Ecological vulnera- bility of the vegetation was divided into four levels, such as extremely fragile, highly fragile, moderately fragile and lowly fragile in the Subei Lake watershed. The extremely fragile area, where buried depth of the groundwater level was generally less than 1.0 meter, distributed in beach zones near the Subei Lake, and its relationship between vegetation and groundwater was close. The lowly fragile areas scattered in the ridge zone around the Subei Lake watershed, where buried depth of the groundwater level was 10.0 -40.0 meters, and their relationship between vegetation growth and groundwater depth was not obvious. Buried depth of groundwater had the most sensitive influence on vegetation ecology, and it was the key factor between utilization of groundwater resources and eco-environment protection in the study area. E Conclusion] The researches provided scientific evidence for regional eco-environment protection, rational development and utilization of water resources, and coordinated development of economy and society.