Evaluation of ecological sensitivity in Lhasa based on an analytic hierarchy process-entropy weight coupling method

The rapid urban development and economic growth of Lhasa pose potential risks to its ecological environment. In order to promote the high-quality, coordinated development of the economy and ecological environment in Lhasa, the ecological sensitivity of Lhasa was evaluated based on the analytic hierarchy process (AHP)-entropy weight coupling method. The elevation, slope degree, slope direction, water buffer zone, vegetation coverage, land use type and average annual rainfall were selected as ecological sensitivity index factors. The weighted values for each index were determined by using the AHP-entropy weight coupling method. It was found that vegetation coverage and average annual rainfall in Lhasa have a significant impact on ecological sensitivity, with weights of 0.266 and 0.213, respectively. Single-factor ecological sensitivity and comprehensive ecological sensitivity analyses were conducted using ArcGIS software. The results indicated that the overall ecological sensitivity of Lhasa is relatively high. The area of highly sensitive and extremely sensitive regions accounts for 41.31%, mainly distributed in the northeastern part of Dangxiong county, the Namtso area, and the vegetation-covered areas of Mozhugongka county, Linzhou county, Nimu county and Qushui county. The area of the moderately sensitive zone accounts for 27.96%, mainly distributed in the human settlement areas of the Lhasa river basin and in the shrubbery and grassland areas with moderate vegetation coverage. The total area proportion of extremely and relatively low sensitivity regions is 30.73%, mainly distributed in the high mountains in the northwest of Lhasa, areas of high human activity, and permanent glacier and snow-covered zones. In the future, Lhasa should enhance overall environmental protection and the rational utilization of land resources. Special attention should be paid to water ecology, vegetation protection and rainfall in highly sensitive areas. At the same time, the impact of regional development on permanent glaciers and snow-covered areas should be taken into consideration.