Accuracy Assessment and Hydrological Effect of GSMAP Precipitation Products in Xijiang River Basin

Satellite precipitation products play an important role in the water industry and the meteorological industry. In order to analyze the application accuracy of satellite precipitation products in the Xijiang River Basin, provide data support for runoff simulation in data-free areas, combined with the daily precipitation product CGDPA based on rain gauge monitoring, the Multi-scale accuracy assessment of the GSMAP was evaluated in the Xijiang River Basin, and the CREST model was used to simulate the runoff and explore its hydrological effects. The results show: GSMAP can better reproduce the spatial distribution of daily precipitation in the Xijiang River Basin, the correlation coefficient on the daily scale is 0.82, and the correlation coefficient on the monthly scale is increased to 0.94, and the correlation coefficients on the four seasons scale are 0.91, 0.89, 0.96 and 0.94, respectively. In the calculation of the frequency of each precipitation level in the Xijiang River Basin, except for the near-no-rain and micro-rainfall, the calculation results of other levels are similar to CGDPA. The GSMAP daily precipitation event detection capability: POD is 0.96, FAR is 0.33 CSI is 0.64. Among the hydrological simulation effects, the Nash efficiency coefficients and correlation coefficients of CGDPA and GSMAP during the whole observation period are: 0.81 and 0.91, 0.81 and 0.83. From this, the following conclusions can be drawn: the correlation coefficient between GSMAP and CGDPA is higher on the daily and monthly scale, but it will change with the seasons; the daily precipitation detection ability of GSMAP is better, and it is better in the hydrological effect assessment. It turns out that GSMAP can replace ground rain gauge data in the Xijiang River Basin, thus facilitating the acquisition of precipitation data.