Quantitative precipitation estimation algorithm for C-band radar situated in complex topographical regions

The accuracy of C-band radar quantitative precipitation estimation (QPE) is affected by many factors, including the following: (1) Calibration of radar observations, (2) interference from non-meteorological echoes, (3) vertical spatial variation of precipitation, (4) severe radar beam blockage by terrain or ground objects, (5) Z-R relationship, (6) multi-radar mosaic method, (7) radar observation echo attenuation, etc. In this paper, the radar quantitative precipitation estimation is conducted based on the C-band weather radar in Shaanxi Province. It improves the accuracy of the C-band weather radar QPE from the aspects of radar quality control, terrain blockage, Z-R relationship and multi-radar mosaic, and produces precipitation type and 1 h QPE products. The spatial and temporal resolutions of the product are 0.01°×0.01° and 6 min, respectively. Through the evaluation of seven precipitation processes, the results show that radar QPE based on hybrid scan reflectivity processing module and precipitation type classification module is close to the precipitation observed by the ground gauge stations. The statistical indicators RMSE of hourly precipitation is stable and below 3 mm, RMAE is about 50% and remains stable, and RMB remains within −30%. The dispersion and absolute deviation of radar QPE products are both low, indicating the radar QPE obtained by this algorithm is stable and reliable.