关键词: 多源降水数据, CMPAS, 精度评价, 地形因子, 最近邻点插值

Abstract: Two sets of multi-source precipitation fusion analysis products FAST and FRT products from 2020 to 2021, and the hourly precipitation data of 35 national meteorological stations in Chongqing after quality control were used to test the correlation and error of the two sets of products in combination with the topographic factors of each station, so as to provide data support for hydrometeorological research under complex terrain. Some results in this study showed that: (1) FAST and FRT products had good correlation with the observed value, positive correlation and small error. The overall product was lower than the observed value, and there was a slight difference between them. (2) On monthly and seasonal time scales, the accuracy of spring was the best, and the error and dispersion degree of flood season from May to September were the largest. (3) With the increase of precipitation grade, the distribution of product error, correlation and TS grade score became more discrete, the absolute value of error gradually increased, the TS grade score gradually decreased, and the correlation first decreased and then increased, among which the correlation of precipitation grade 0.1-1.9mm and ≥ 20mm was better. (4) In terms of terrain factors, the accuracy of products was slightly different, among which the accuracy of products on the slope was the best, followed by the flat slope, above the steep slope and gentle slope. The accuracy of products with undulation greater than 70m was the best; With the increase of altitude, the product accuracy decreased first. When the altitude was greater than 700m, the product accuracy increased. The accuracy of products with the Southwest and East slope directions was better, and the Southwest slope direction was the best. FAST and FRT precipitation products had high accuracy in Chongqing, which could effectively supplement the precipitation data in areas with few automatic stations.

Key words: Multi-source precipitation data, CMPAS, Accuracy evaluation, Terrain factor, Nearest neighbor interpolation