Spatiotemporal characteristics of karst rocky desertification and the impact of human activities from 2010 to 2015 in Guanling County, Guizhou Province

: Karst rocky desertification (KRD) is one of the most important environmental problems in the karst area of Southwest China. Studies of KRD process and its driving mechanism have been the hot spots in the related research fields and particularly, the impact of human activities on KRD remains to be further studied. In this study, Guanling County of Guizhou Province, where KRD is extremely serious, was selected as the research area. Using SPOT5/ALOS data in 2010, GF-1/ZY-3 data in 2015, and information from field investigations, the KRD spatial distribution and KRD change data were obtained by visual interpretation. Based on the examination of the spatiotemporal change characteristics of KRD, the impact of human activities such as land use, socioeconomic development level, and KRD restoration projects were analyzed. The results of this study show that: 1) The KRD land in Guanling County is dominated by moderate KRD, and it occupies more than 45% of the total land area in 2015. 2) The deteriorating trend of KRD in Guanling County has been effectively controlled. The area of KRD land is decreasing year by year, and most of the KRD land is in a stable state, especially that the severe KRD land and the extremely severe KRD land are clearly reduced, but some of the KRD land is still deteriorating. 3) Human activities play important roles on KRD change. First, land use types, especially shrub forest land, non-irrigated farmland, and forestry land have important influences on the change of KRD. Second, the higher the population density and GDP, the higher the degree of KRD and the less the effect of restoration. The KRD restoration projects in Guanling County have made remarkable achievements, where about one-third of the stable and improved KRD lands were a result of these restoration projects.