Research on the 40-year growth period of rocky desertification in karst area of Guangxi based on DISP images

Rocky desertification is a natural occurrence of soil degradation and alteration in land characteristics, characterized by exposed bedrock, prevalent in the three southwestern provinces, with Guangxi seeing particularly severe effects. Desertification had an increase from the 1960s to 2005, and has progressively improved since then due to the government's desertification control policy. The entire extent and distribution of rocky desertification in Guangxi during the 1960s were derived by thorough methods utilizing DISP photos from the United States as the data source, while the thematic map of rocky desertification in Guangxi for 2005 was generated using Landsat images. Utilizing spatio-temporal analysis, an examination of the spatio-temporal evolution of rocky desertification in Guangxi over a forty-year period was performed. The findings indicate that from 1965 to 2005, the annual evolution rate of rocky desertification was 1.7%, corresponding to an annual increase of 0.04 million square kilometers. Conversely, between 2005 and 2011, the reduction rate of rocky desertification was 3.92%, equating to an annual decrease of 0.076 million square kilometers. The spatial increase of rocky desertification over the past 40 years is predominantly concentrated in the central region, including Hechi, Liuzhou, and Laibin. This phenomenon is primarily located in areas characterized by karst topography and high population density, where the conflict between human activity and land use is pronounced. The investigation of alterations in the rocky desertification environment revealed significant changes in the landscape of the research area.