Contrasting the Contributions of Climate Change and Greening to Hydrological Processes in Humid Karst and Non-Karst Areas

A quantitative assessment of the responses of hydrological processes to environmental change is vital for the sustainable utilization of groundwater and sustainable development under the dual influences of climate change and global greening. However, few studies have investigated the differences in hydrologic responses between karst and non-karst regions. Thus, we analyzed the spatiotemporal changes in potential groundwater recharge (PGR), potential groundwater recharge as a proportion of precipitation (PGR/P), and actual evapotranspiration (AET) in karst and non-karst regions for 1982–2020 using the V2karst model. The analysis revealed the following results: (1) The V2karst model efficiently monitored variations in the AET and groundwater depth (GWD), which indicated its suitability for use in karst areas. (2) The PGR, PGR/P, and AET increased at rates of 4.9 mm/y, 0.0011, and 1.4 mm/y in karst areas, and 3.8 mm/y, 0.00053, and 1.6 mm/y in non-karst areas, respectively, with the increasing trend in AET being significant in karst and non-karst regions. (3) The precipitation (P) and AET were significantly correlated with the PGR and PGR/P, while the minimum temperature (TMN) was strongly related to the AET. The Normalized Difference Vegetation Index (NDVI) moderately affected the PGR, PGR/P, and AET changes in humid catchments. Climate change is a primary factor for hydrological processes, whereas vegetation restoration has a relatively minor impact. The results of this study are beneficial toward the adoption of strategic groundwater utilization programs and ecological restoration measures for regions with a diverse geological setting.