Sensitivity evaluation of Karst rock desertification based on its formation mechanism: A case study of Qianxi County in Guizhou Province

Based on remote sensing interpretation and field investigation, this paper analyzes the causes and formation mechanisms of rocky desertification, aiming to identify the impact of key natural factors on the sensitivity of Karst rock desertification. The annual rainfall, slope, lithology, soil texture, and vegetation coverage are selected as indicators for evaluating the sensitivity of Karst rock desertification. The sensitivity evaluation of Karst rock desertification is carried out by using improved analytic hierarchy process, with the support of GIS, in Qianxi County, Guizhou Province. The results reveal that Karst rock desertification remains sensitive, with the total area of moderate, strong, and extremely high sensitivity amounting to 1176.39 km², representing 46.97% of the studied areas, and the possibility of Karst rock desertification still exists. The moderate, strong and extremely sensitive areas are mainly distributed in Hongshui-Renhe, Dingxin-Chongxin, Wuli-Shajing and Zhongshan-Tieshi-Supu, which are consistent with the distribution pattern of rocky desertification land. Most of the strong sensitive and extremely sensitive areas of rocky desertification are distributed in the Triassic carbonate strata, and the Jialingjiang Formation is the most sensitive stratigraphic unit. Through comprehensively studying the mechanism of various related factors of rock desertification and comparing the importance of each related factor based on their internal relationships and inheritance relationships, we can replace expert questionnaire methods to reduce the arbitrariness and subjectivity of the analytic hierarchy process.