Runoff Simulation In The Middle And Upper Reaches Of Huaihe River Basin Based On Multi-source Satellite Precipitation Date

Accurate precipitation data is of great significance for improving forecast accuracy of drought and flood and disaster prevention and mitigation.Satellite precipitation data has the advantages of short time period,high spatial resolution and wide coverage,and has been widely used in hydrological simulation and weather forecast,etc.However,there are certain uncertainties in the application process,and accuracy evaluation is needed before use.To solve this problem,this paper studies the application of three satellite precipitation products,GPM,TRMM and PERSIANN,in runoff simulation in the middle and upper reaches of the Huaihe River Basin.Firstly,the precipitation data of ground stations in the middle and upper reaches of the Huaihe River Basin were used as the reference value and divided into daily,monthly and seasonal scales.The accuracy of precipitation data of GPM,TRMM and PERSIANN from 2008 to 2018 was evaluated on different time scales.Then,SWAT model was constructed by selecting the middle and upper reaches of the Huaihe River Basin.Finally,the satellite precipitation data were input into SWAT model for runoff simulation,and compared with the measured runoff to evaluate the applicability of satellite precipitation data in hydrological forecasting.The results are as follows:(1)On the daily scale,GPM and TRMM are close,with correlation coefficients of0.55 and 0.54,respectively,and relative deviations of about 7.5%.The correlation between the three satellite precipitation products and the precipitation data of ground stations will increase with the increase of time scale.The three satellite data all underestimate the precipitation events of 0-1mm,and overestimate the precipitation events of 10-25 mm.In the description of spatial distribution characteristics,GPM precipitation products perform well,while TRMM data and PERSIANN data are somewhat overestimated.(2)The constructed SWAT model has good adaptability in the middle and upper reaches of the Huaihe River Basin.The Nash-Sutcliff Efficiency of the periodic and validation periods are 0.74 and 0.75,respectively,and the Determination coefficients are0.73 and 0.71,respectively,which can be used to evaluate the performance of GPM,TRMM and PERSIANN satellite rainfall data in the middle and upper reaches of the Huaihe River basin.(3)In daily scale runoff simulation,station data,GPM data and TRMM data are highly correlated with actual runoff data;The NS values of simulated runoff from site data,GPM data and TRMM data were 0.76,0.75 and 0.65,respectively.PERSIANN,with a coefficient of determination of 0.61 and NS value of 0.52,is the worst of the three satellite precipitation data in terms of runoff process simulation and peak time capture.Among the three kinds of satellite data,GPM data has the best effect of simulating runoff,and both mean and total distribution are closer to the measured runoff than the other two kinds of satellite data.In the monthly scale runoff simulation,NS and Determination coefficients of simulated and measured runoff values for all three data exceeded 0.70.GPM precipitation data was slightly better than site data,followed by TRMM precipitation data,and PERSIANN precipitation data was the worst.In conclusion,accuracy of multi-source satellite rainfall products,studies its applicability in the huaihe river basin runoff simulation for scientific management of huai river basin water resources management to provide important theoretical reference and technical support,for positive response and watershed management department to slow the effects of climate change,disaster prevention and mitigation is of great significance.