Quantitative Characteristics of the Current Multi-Source Precipitation Products over Zhejiang Province, in Summer, 2019

Precipitation data with fine quality plays vital roles in hydrological-related applications. In this study, we choose the high-quality China Merged Precipitation Analysis data (CMPA) as the benchmark for evaluating four satellite-based precipitation products (PERSIANN-CCS, FY4A QPE, GSMap_Gauge, IMERG-Final) and one model-based precipitation product (ERA5-Land), respectively, at 0.1 degrees, hourly scales over the Zhejiang province, China, in summer, from June to August 2019. The main conclusions were as follows-(1) all other products demonstrate similar patterns with CMPA (similar to 325.60 mm/h, std similar to 0.07 mm/h), except FY4A QPE (similar to 281.79 mm/h, std similar to 0.18 mm/h), while, overall, the PERSIANN-CCS underestimates the precipitation against CMPA with a mean value around 236.29 mm/h (std similar to 0.06 mm/h), and the ERA5-Land, GSMap_Guage, and IMERG-Final generally overestimate the precipitation with a mean value around 370.00 mm/h (std similar to 0.06 mm/h). (2) The GSMap_Gauge outperforms IMERG-Final against CMPA with CC similar to 0.50 and RMSE similar to 1.51 mm/h, and CC similar to 0.48 and RMSE similar to 1.64 mm/h, respectively. (3) The PERSIANN-CCS significantly underestimates the precipitation (CC similar to 0.26, bias similar to-35.03%, RMSE similar to 1.81 mm/h, probability of detection, POD, similar to 0.33, false alarm ratio, FAR,similar to 0.47), potentially due to its weak abilities to capture precipitation events and estimate the precipitation. (4) Though ERA5-Land has the best ability to capture precipitation events (POD similar to 0.78), the largest misjudgments (FAR similar to 0.54) result in its great uncertainties with CC similar to 0.39, which performs worse than those of GSMap_Gauge and IMERG-Final. (5) The ranking of precipitation products, in terms of the general evaluation metrics, over Zhejiang province is GSMap_Gauge, IMERG-Final, ERA5-Land, PERSIANN-CCS, and FY4A QPE, which provides valuable recommendations for applying these products in various related application fields.