Agricultural drought-driven mechanism of coupled climate and human activities in the karst basin of southern China

The timely and accurate agricultural drought monitoring and an analysis of drought-driven mechanisms in karst basins in the context of global warming are of great significance for drought disaster monitoring and sustainable ecological development in a basin. In this paper, based on MODIS data, meteorological and topographic data and land use data from 2001 to 2020, we used the Sen slope, the Mann-Kendall test and geographic detector to explore the agricultural drought driving mechanism of climate change and human activities in the karst basin of southern China from 2001 to 2020. The results showed that 1) the annual and seasonal scale rainfall and temperature in the karst basin in southern China had an increasing trend; the spatial distribution of rainfall mainly showed a gradual increase from west to east, and the temperature gradually increased from east to west. 2) The intensity of agricultural drought in southern China showed a decreasing trend in the year, spring, summer, and autumn and an increasing trend in the winter; moreover, the spatial variation in drought increased significantly in the year and the western part in the four seasons and decreased significantly in the year, the southern part in autumn, and the central part in spring and winter. 3) The drought intensity of agricultural drought in the southern Chinese karst climate change and human activities in the watershed had a significant impact on agricultural drought, with climate change driving drought the most, followed by watershed characteristics, and human activities driving drought to a lesser extent; multifactor coupling drove drought follows: rainfall ( q  = 0.424) > temperature ( q  = 0.340) > elevation ( q  = 0.219) > land utilization ( q  = 0.188 ) > population density ( q  = 0.061) > slope ( q  = 0.057). Therefore, revealing the mechanism of agricultural drought in the karst basin through the study of this paper has important theoretical significance and technical guidance for drought relief in the karst area.