Influence of geological and geomorphologic features on karst rocky desertification in northwestern Hunan Province：A case study of Zhangjiajie City

This work made an overlay analysis using geographic information technology （GIS）， DEM，geological structure，lithological characteristics and geomorphological data. The objective was to examine the influence of geological and geomorphological factors on the distribution of karst rocky desertification in the Zhangjiajie area， northwestern Hunan Province. The results show that the occurrence rate of karst rocky desertification in this area exhibits the characteristics of hilly>depressions> low mountains> middle mountains> high mountains. In terms of slope，the occurrence rate of rocky desertification is the highest among the grade II slopes，and the rocky desertification area is sunny. The distribution is featured by slope>semi-shady slope>shady slope>semi-sun slope，and with the slope direction from cloudy to sunny，the proportion of karst rocky desertification area of various grades gradually increases. In terms of stratum lithology，carbonate and clastic interbedded rock formations are more prone to karst rocky desertification. In terms of geological structure，the spatial distribution of rocky desertification is in the same direction as the fault structures，and the influence of faults on rocky desertification is mainly reflected in the impact on the two walls in the IB fault. The differences in lithology and strata pose influence on the development and distribution of water systems.