Spatial distribution and driving factors of karst rocky desertification in Southwest China based on GIS and geodetector

Abstract

Rocky desertification is a pressing environmental concern in Southwest China, and it significantly impacts local living conditions and regional sustainability. Employing remote sensing on a macro scale, this study focuses on identifying and analyzing the spatial distribution and driving factors of rocky desertification. Conducted in Southwest China, using Landsat data from Google Earth Engine, the research quantitatively extracts information on rocky desertification patches through spectral analysis methods. We investigated the spatial distribution characteristics and driving factors of rocky desertification through geographic information system spatial analysis and a geodetector model. The main conclusions are as follows. The area of rocky desertification in Southwest China covers 217530.4 km² (accounting for 15.6% of Southwest China), with areas of slight, moderate, and severe rocky desertification at 81.3, 7.1, and 11.6%, respectively. Spatially, rocky desertification is primarily distributed in areas where lithology is carbonate rock between clastic rocks and continuous limestone, slope exceeds 15°, elevation range is 1,000–2,000 m, land use types are grassland and woodland, precipitation is 80–120 mm, and population density is below 50 people/km². Human activities have a minimal influence in comparison to natural factors. Geodetector analysis identifies lithology, land use types, and slope as primary driving factors, with interactive effects of lithology and land use type and slope and land use type jointly influencing rocky desertification formation in Southwest China. The results of the study provide a scientific basis for an in-depth understanding of rocky desertification in Southwest China and for the management of rocky desertification.