GPM IMERG降水产品在珠江流域的适用性分析

Applicability of GPM IMERG Satellite Precipitation Product in Pearl River Basin

以珠江流域为研究区域,以CMFD再分析降水数据集为基准值,对2010~2018年的GPM卫星降水产品进行适用性评价,主要从多时间尺度精度表现、日降水探测能力、极端降水监测能力等方面进行分析。结果表明,该降水产品在珠江流域具有较高的观测精度,多年平均相对偏差仅为3.78%,皮尔逊相关系数高达0.96;该卫星降水产品对日降水的探测能力与降水强度关系密切,降水强度越大,探测能力越弱,当日降水强度为5 mm/d左右时,探测能力最佳;此外,该卫星降水产品对珠江流域极端降水事件的监测能力较好,能准确刻画出极端降水的空间分布特征。整体来看,GPM卫星降水产品在珠江流域具有较高的应用潜力,可为流域降水监测、降水过程再现等工作提供数据支持。

Taking CMFD as the reference data to evaluate the applicability of GPM satellite precipitation product in the Pearl River basin from 2010 to 2018,and the daily precipitation detection ability and extreme precipitation monitoring ability of GPM are also analyzed.The results show that GPM has high observation accuracy in Pearl River basin,the multi-year mean relative bias is only 3.78%,Pearson's correlation coefficient is 0.96;The detection ability of GPM precipitation product to the daily precipitation is closely related to the precipitation intensity,the greater the precipitation intensity,the weaker the detection ability,when the precipitation intensity is about 5 mm/d,the detection ability is the best;GPM has a good monitoring ability for extreme precipitation events in the Pearl River basin and can describe the spatial distribution of extreme precipitation accurately.Overall,GPM has a high application potential in the Pearl River basin,it can provide a great support for precipitation monitoring and precipitation information reanalysis.