Spatial and temporal dynamics of desertification and its driving mechanism in Hexi region

Investigating the spatio-temporal patterns of desertification and its driving mechanisms is crucial for efforts to improve the ecology and environment and combat desertification. Based on meteorological and satellite remote sensing data, this paper analyzed the dynamic characteristics of desertification in the Hexi region of arid and semiarid land in Northwest China from 2000 to 2018 using a dimidiate pixel model; revealed the relationship between desertification evolution characteristics and climatic variations and anthropogenic events based on the change characteristics of net primary productivity (NPP); and then clarified the response of desertification to climatic variations and anthropogenic events using a geodetector model. Outcomes show that: (1) overall desertification in Hexi region is at a serious level, but during the study period, severe desertification decreased, mainly concentrated in the east and southwest, and non-desertification increased, mainly near the Qilian Mountains and Shule River basin; (2) there were both spatial and temporal dynamics during the study period, with severe desertification decreasing by 11% and moderate, light, and non-desertification increasing by 3%, 5%, and 3% respectively; (3) during 2000–2005, human activities, climate change, and their joint contribution to desertification reversal were similar, i.e., 23%, 40%, and 36%, and the former two contributed equally to desertification expansion, 38% and 41%, respectively; climate change predominated in desertification reversal in 2005–2010 and 2015–2018, while human activities predominated in desertification expansion; human activities predominated in desertification reversal and climate change predominated in desertification expansion in 2010–2015. This research can provide a theoretical basis and technical support for ecological and environmental management and sustainable socio-economic development in arid and semiarid regions.