Ecological Environment Security Analysis of Yushu Tibetan Autonomous Prefecture Based on GIS and RS

Yushu Tibetan Autonomous Prefecture is located in the Three Rivers Source area, which is known as the "water tower of China". However, due to the restriction of natural conditions, the ecological environment of Yushu Prefecture is extremely fragile and its self-recovery ability is poor. Based on the DPSIR concept model, this study collected the ecological environment and socio-economic data of Yushu Tibetan Autonomous Prefecture in 2000, 2005, 2010 and 2015, and established a dynamic evaluation model of ecological security by using expert scoring method and analytic hierarchy process. The weights of each index are determined and the data are standardized to analyze the temporal and spatial changes of ecological security in Yushu area. The results show that the change range of ecological security in Yushu Prefecture is less than 5%, and there is a weak tendency to develop to both ends. In terms of space, the ecological security situation in the southeast of Yushu Prefecture is better than that in the northwest, showing the distribution characteristics of insecurity in the northwest, early warning in the middle and safety in the southeast