Evaluating Spatiotemporal Variations of Groundwater–Surface Water Interaction Using an Integrated Hydrological Model in Huashan Basin, China

Quantifying the spatiotemporal variations of basin-scale surface water (SW)–groundwater (GW) interactions is vital for conjunctive management resources in basin. In this study, an integrated hydrological model (SWAT-MODFLOW) used to simulate SW–GW system Huashan Basin. The numerical was calibrated and validated using streamflow observations watershed outlet groundwater levels long-term monitoring wells from 2016 2020 study area. results show that SWAT–MODFLOW can achieve a better fit discharge, compared with single SWAT model, R2 (coefficient correlation) NSE (Nash-Sutcliffe efficiency coefficient) 0.85 0.83, respectively. table fitting indicate RMSE reach 0.95 0.88, budgets analysis demonstrates average rate (0.5281 m3/s) GW abstraction SW larger than (0.1289 recharge GW. Moreover, exchange gradually reaches peak value June August, lowest shown April, each year. Based on IPPC6 CanESM5 dataset supplied by Canadian Climate Centre, regional precipitation scenario subject climate change predicted ASD (Auto Statistical Downscaling Model) statistical downscaling method, under scenarios SSP2_4.5 SSP5_8.5. interaction pattern modeled future current (2016–2020) annual considered as base value. Subject scenario, 0.1583 m3/s, which increase 22.8%. discharge 0.5189 m3/s reduction 0.017%. SSP5_8.5 0.1469 14.7%. 0.5953 increases 12.7%. assist resource basin, identifying potential locations nutrient transport aquifer river, well changes spatial variability climatic conditions.