Prediction of the soil water content in the Luanhe river basin based on CMIP6

Abstract

A hydrological model (Soil and Water Assessment Tool, SWAT) of the Luanhe River Basin was built based on collected hydrological and meteorological data to better understand how the soil water content varies under climate change. To assess the applicability of the eight selected global climate models (GCMs), four single indicators and one comprehensive indicator were calculated at multiple stations. According to the evaluation results, a weighted multimode ensemble was established. To downscale and correct the deviation from the meteorological data while maintaining the trend signal, the enhanced Delta-DCSI technique was utilized. Eventually, the corrected GCM data were used to drive the SWAT model to simulate the spatial and temporal changes in the soil water content in the Luanhe River Basin under future scenarios. The results indicated that (1) the SWAT model was suitable for and capable of simulating hydrological processes in the basin; (2) the SWAT model can be accurately driven by multimodel ensemble data after model optimization; (3) the soil water content in the basin slowly increased and fluctuated over time; and (4) in the future, lower soil water contents will occur in a few northern subbasins, and consistently higher water contents will occur in the remaining areas. The findings could provide a scientific basis for water resource management and ecological environmental protection in the Luanhe River Basin.