Applicability And Runoff Simulation Of Satellite Precipitation Data

Due to the wide and extremely uneven distribution of rainfall and the relative concentration of rainstorm,millions of people in China are suffering from different degrees of rainstorm and flood every year.Therefore,how to access to reliable precipitation data in time,and further obtain the spatial distribution of rainstorm and the runoff of flood are the significant,which is an effective way to deal with such disasters.In this paper,firstly,we evaluated the applicability of satellite precipitation data TRMM 3B42 and its successor GPM IEGRG.Furthermore,we analysed the space-time of rainstorm based on satellite precipitation data.Finally,the adjusted satellite precipitation data based on geographical adjustment model are applied to the hydrological model in the upper and middle Yangtze River basin and the Hanbei River basin,and the results show that:(1)TRMM 3b42 and its successor GPM IMERG satellite precipitation data both performed well in gridcell and basin scale in Hubei province for 1-hour and 1-day time sacle.TRMM 3b42 and GPM IMERG underestimated and overestimated the rain-gauge observations precipitation respectively,and the correlation of satellite data on the 1-day scale was significantly higher than that of 1-hour time scale and the basin precipitation was higher to the point precipitation.However,the evaluation indices of GPM IMERG had different degrees of decline compared with the TRMM 3b42 except POD and CC;(2)The calculation areas of rainstorm center using fast accumulative precipitation and spatial data interpolation method and one key modal identified by EOF analysis method are basically consistent in space distribution,and the key modal identified by EOF analysis method instructs the critical precipitation;(3)TRMM 3b42 satellite precipitation data performed well in gridcell and basin scale in Yangtze River basin for 1-day time sacle,and the geographical adjustment model mothod we proposed based on additive error adjustment model modified the applicability evaluation indices;(4)In upper and middle Yangtze River basin,the simulation runoff of TRMM 3b42 satellite precipitation data performed well in 1-day time scale.In addition,the Xinanjiang model is better than TANK model,and geographical adjustment model improved the problem of simulation runoff flood peak delay by the original satellite rainfall data,so it is necessary to adjust the TRMM 3b42 satellite precipitation data in the runoff simulation;(5)In Hanbei River basin,the simulation runoff of adjusted TRMM 3b42 satellite precipitation data performed not so well in 1-hour time scale in small and general flood because the error flood peak time was more serious than rain-gauge observations.Nevertheless,the flood runoff simulation accuracy is high in bid flood,which indicated that the TRMM 3b42 satellite precipitation data have obvious disadvantage among small and general flood while available among big flood in runoff simulation in small basin.