多源融合降水实况分析产品在海河流域的适用性评估

Assessing the Applicability of National Multisource Precipitation Analysis Product in the Haihe River Basin

基于逐小时地面站点降水观测数据和国家气象信息中心研发的5 km多源融合降水实况分析产品,采用算术平均法对2021年6~9月海河流域面雨量进行估算。通过相关系数、平均误差和均方根误差等多种评估指标,客观定量评估多源融合降水实况分析产品在海河流域的适用性。结果表明:多源融合降水实况分析产品与地面观测资料估算的面雨量结果基本一致,能较好地反映2021年6~9月海河流域面雨量的时空变化特征,但在量值上存在高估且随着降水量增加,估算误差也越大。分区对比,融合实况分析产品和站点的误差与子流域的平均降水量、海拔高度和面积密切相关。对于各量级面雨量出现的频次,融合实况分析产品与站点整体相差不大,准确率可以达到90%及以上。总体而言,5 km多源融合降水实况分析产品的质量较高,可进一步应用于海河流域精细化面雨量监测业务中。

Based on the ground-observed hourly precipitation data and the China multisource precipitation analysis(CMPA)product developed by the National Meteorological Information Center,the areal rainfall of the Haihe River basin from June to September 2021 is estimated using the arithmetic mean method.We objectively and quantitatively evaluated the applicability of the CMPA product with a resolution of 5 km in the Haihe River basin using multiple evaluation indicators,such as the correlation coefficient,average error,and root-mean-square error.The results show that the CMPA product is consistent with the ground observation data,reproducing better spatial and temporal variation characteristics of the areal rainfall in the Haihe River basin from June to September 2021.Compared with the ground observation,the CMPA product overestimated the areal rainfall of the Haihe River basin,and the larger the precipitation,the larger the error observed in the CMPA.By comparison,errors observed between the ground observation and CMPA product are closely related to the average precipitation amount,altitude,and area of the sub-basin.In terms of the areal rainfall frequency at individual magnitudes,the CMPA product is close to the ground observation,with an accuracy of over 90%.In short,the quality of the CMPA product is high;therefore,it can be applied to meteorological operations for the areal rainfall refinement in the Haihe River basin.