Application of Multi-Source Precipitation Merged Products and Intelligent Grid Weather Forecast in a Flood Forecasting in Weihe River Basin

Wang Zhenya; Wang Di; Dong Junling; Ge Zhenfei

doi:10.16765/j.cnki.1673-7148.2024.05.002

Abstract：The application experiment of multi-source precipitation merged products and intelligent grid forecast in flood simulation is carried out based on the flood process from June 28 to July 15,2018 at Weijiabao hydrological station of the Weihe River.The results indicate that both multi-source merged pre-cipitation and station-observed precipitation can be used as input data to simulate the flood process effec-tively.It is feasible to use multi-source precipitation merged products instead of site precipitation for flood simulation analysis and calculation in river basin without precipitation observation data,but the simulated runoff depth and peak flow are relatively smaller as multi-source merged precipitation tends to underesti-mate precipitation.The runoff yield is significantly different when the areal rainfall in 48 h before the flood peak is not much different in two flood processes at Weijiapbao hydrological station,indicating that the soil moisture in the early stage has a great influence on the runoff yield in the Weihe River basin.Therefore,special attention should be paid to the impact of persistent precipitation during flood control.The forecast period of flood could significantly extend from 12 h to 84 h,as it is 12 h using observed pre-cipitation but 84 h taking intelligent grid weather forecast as precipitation input.However,the relative er-ror of simulated runoff depth and peak flow are relatively large as the intelligent grid precipitation forecast is likely to overestimate the areal rainfall.In order to improve accuracy of areal rainfall forecast,it is sug-gested to research the areal rainfall correction method according to different weather backgrounds,and further improve the accuracy of flood forecast while extending forecast period of flood.