TRMM/GPM和Stage Ⅳ降水产品在小流域水文模拟效用评估

The accuracy of TRMM 3B42 V7, GPM-IMERG satellite precipitation, and Stage Ⅳ radar precipitation was compared and analyzed in the Little Washita River Basin, Oklahoma, the USA, using ground observation precipitation reference. The CREST, a distributed hydrological model, was driven by these three precipitation products and evaluated its hydrological simulation utility. The research shows that the correlation coefficient among the three kinds of precipitation products and ground precipitation is more significant than 0.5, and passed the 0.05 confidence level test. GPM-IMERG and TRMM 3B42 V7 precipitation have the underestimation of no rain and light rain, and the overestimation of heavy rain and violent rain. In general, Stage Ⅳ has the best precision, and, GPM precipitation accuracy is better than TRMM 3B42 V7. In the hydrological simulation utility evaluation, the same calibration period was set and the CREST model parameters were calibrated using three kinds of precipitation products. After the set of parameters was obtained, the basin's daily runoff process was simulated in the same validation period. The comparison results show that Stage Ⅳ radar precipitation has the best effect in small watershed hydrological simulation, followed by GPM-IMERG, but TRMM 3B42 V7 simulation effect is not ideal.