Coupling analysis of short-term weather and runoff in an arid lake basin of China

Changes in the weather will cause variations in the hydrological system. Arid areas, with fragile hydrological systems, are very sensitive to changes in the weather, so the coupling analysis of short-term weather and runoff in arid areas is of great significance. The Daihai Lake is a closed inland lake in an arid area of China. In this paper, Weather Research and Forecasting model mode-Hydrological module (WRF-HYDRO) is used to simulate the coupling of weather and hydrology in the Daihai Lake Basin. Regional optimization of WRF-HYDRO is carried out to determine the optimal parameters. The optimal WRF-HYDRO model is applied to couple the short-term weather and runoff in the Daihai Lake Basin to reproduce several rainstorm and flood events. It is found that runoff infiltration parameter (REFKDT) in WRF-HYDRO is the parameter that has the most severe effect on runoff in the Daihai Lake Basin. WRF-HYDRO can capture the rainstorm moment of the rainstorm events in the Daihai Lake Basin, especially the first rainstorm moment, and its simulation accuracy is good. WRF-HYDRO has a strong ability to capture flood peak, but there is a discrepancy between WRF-HYDRO flood peak and Soil Conservation Service Curve Number (SCS–CN) calculation result at the flood peak moment. The northern part of Zuoyun County should guard against the occurrence of flood disaster in wet season. The coupling of weather and hydrology can not only make up for the lack of runoff data in arid basins, but also provide a basis for water resources management and disaster prevention and mitigation in the basins.