渭河流域GPM卫星降水产品的多尺度评估

Multi-Scale Assessment of GPM Satellite Precipitation Products in Weihe River Basin

为探究全球降水观测计划GPM下IMERG系列与GSMaP系列中的近实时(IMERG-Early,IMERG-Late,GSMaP-NRT)和后实时(IMERG-Final,GSMaP-Gauge,GSMaP-MVK)遥感降水产品在复杂地形流域的精度和适用性,基于渭河流域内雨量站数据,在不同空间尺度与时间尺度上对遥感降水的精度评价指标(CC,RMSE,BIAS)和降水能力探测指标(POD,FAR,CSI)进行综合评估,同时采用IHACRES水文模型对卫星降水数据在径流模拟中的适用性进行了评估。结果表明,GSMaP-Gauge(CC=0.55,RMSE=5.09,Bias=0.3%)与IMERG-Final(CC=0.458,RMSE=5.92,Bias=8%)降水产品均能较为准确地反映降水的时空分布特征,但普遍存在对降水的高估;GSMaP与IMERG系列数据在冬季对降水的探测能力(POD<0.4)远低于其他季节;卫星降水数据受海拔因素影响明显,随海拔上升数据质量呈下降趋势;IMERG-Final驱动的IHACRES模拟表现最好(NSE=0.856),由GSMaP-Gauge与IMERG-Final为驱动的水文模型月尺度纳什效率系数均大于0.8,可作为降水驱动数据用于区域的水文过程模拟。

To explore the accuracy and applicability of near real-time(IMERG-Early,IMERG-Late and GSMaP-NRT)and post-realtime(IMERG-Final,GSMaP-Gauge and GSMaP-MVK)remote sensing precipitation products from the global precipitation measurement(GPM)program in complex terrain basins,this study conducted a comprehensive assessment on the accuracy evaluation indexes(CC,RMSE and BIAS)and precipitation capacity detection indexes(POD,FAR and CSI)of remote sensing precipitation based on rain gauge data in the Weihe River Basin across various spatial and temporal scales.Additionally,the IHACRES hydrological model was employed to assess the applicability of satellite precipitation data in runoff simulation.The results show that both GSMaPGauge(CC=0.55,RMSE=5.09 and Bias=0.3%)and IMERG-Final(CC=0.458,RMSE=5.92 and Bias=8%)precipitation products accurately reflect the spatiotemporal distribution characteristics of precipitation but generally tend to overestimate the precipitation.The data of precipitation products in GSMaP and IMERG series exhibits significantly obviously lower precipitation detection capabilities in winter(POD<0.4)than in other seasons.The satellite precipitation data is significantly affected by altitude,and its quality declines with increasing altitude.The IHACRES model driven by IMERG-Final performs the best(NSE=0.856),with monthly Nash efficiency coefficients greater than 0.8 for hydrological models driven by GSMaP-Gauge and IMERG-Final,suggesting that these data can be used as precipitation inputs for regional hydrological process simulation.