Abstract:

Because of the fragility of ecological environment and the influences of human activities,ecoenvironmental problems in karst regions are serious.It’s necessary to identify the sensitive region that is prone to be degraded for ecological restoration and rehabilitation. Based on GIS,four sensitivity factors,that is,water and soil loss,rocky desertification,acid rain,and bioinhabitation,were selected to assess the ecoenvironmental sensitivity.The degree of ecological sensitivity and their spatial distribution in karst regions of southwest China were explored with analytic hierarchy process (AHP) and comprehensive index.The results showed that the sensitivity of water and soil loss,rocky desertification and acid rain was generally high.More than 60% of karst regions were moderate and even more sensitive to water and soil loss sensitivity,rocky desertification,and acid rain sensitivity;while the sensitivity of bioinhabitation was relatively low, with the proportion of 40% of insensitivity.Our study indicates that the sensitivity of ecoenvironment in karst regions of southwest China was high;more than 80% of karst regions are moderate and even more sensitive regions.The insensitive regions were mainly distributed in middle and south Hunan,southeast Hubei,karst peak forest plain of middle Guangxi,intermountain basin and valley of Yunnan and Guizhou. Geological setting,topography and climatic factors were the dominant factors affected the regional ecoenvironment sensitivity