Abstract:How to extract the echo intensity used for quantitative precipitation estimation (QPE) from the 3 D mosaic data of China New Generation Weather Radar (CINRAD) is the key to improve the radar rainfall estimation. With the purpose of analyzing hybrid echo intensity quality extracted from the 3 D mosaic data and the influence on the precipitation estimation, by using the radar data of Zhejiang Province and nationwide rainfall station data, this paper studies the relationship between the echo intensity and the suface precipitation amount and analyzes several factors that affect the accuracy of precipitation estimation. According to the ratio distribution, which is got by the whole weather process accumulation of precipitation estimation from the radar echo intensity and the collected rainfall from the automatic rainfall stations in Zhejiang Province and the surrounding areas, several abnormal regions are found including the region where regional echo intensity is relatively high, the region where regional echo intensity is underestimated, the region where regional echo intensity varies with topography, the region where regional echo intensity is estimated to be relatively reasonable and the region where regional echo intensity is gradually overestimated with increasing latitude. The analysis results show that the 0℃ bright band, the residual ground echo, the abnormal radar echo intensity vertical profile, the quality of the rainfall station data, etc. are causes for the abnormal relationship between echo intensity and ground precipitation amount. Finally, by using parts of the rainfall station data, the precipitation estimation from the radar is corrected and the results show that the rainfall station correction can alleviate the degree of the regional overestimation or underestimation to some extent.