Relationships among vegetation restoration, drought and hydropower generation in the karst and non-karst regions of Southwest China over the past two decades

To curb the intensification of desertification, China has implemented a series of measures to control rocky desertification. However, the interaction between vegetation restoration and the frequent occurrence of extreme weather events has complicated the drought situation in Southwest China. Therefore, in this study, the vegetation health index (VHI) was used to analyze the spatiotemporal variations in drought. Additionally, the fractional vegetation cover (FVC), VHI, vegetation condition index (VCI), and temperature condition index (TCI) were compared between karst and non-karst regions. Additionally, the driving factors of drought and the response of hydropower generation (HG) to drought conditions were explored. The results revealed that (1) after the implementation of measures to combat desertification, the FVC and VHI increased annually by 0.37 % and 0.801, respectively, from 2002 to 2022. In Southwest China, the increase rates of the VCI and TCI were 1.993 and 0.349 yr , respectively, with VCI increase as a key factor in enhancing the VHI. (2) VHI improvement in karst regions was significantly greater than that in non-karst areas, indicating effective rocky desertification control efforts. (3) The geodetector analysis results indicated that the topography is the primary factor influencing the spatial distribution of drought in Southwest China, followed by climatic factors. (4) During drought occurrence, the gap between HG and the total electricity consumption in Southwest China increased, leading to increases in fossil fuel-based power generation and pollutant emissions.