北江飞来峡流域TRMM卫星降雨数据适应性研究

近年来TRMM卫星降雨数据的精度和适应性备受关注，以位于亚热带季风气候区的典型流域——北江飞来峡流域为研究区，利用24个实测站点降雨数据对TRMM数据集进行时空精度和准确性分析；采用CDD、CWD和RX5day等指标研究流域内极端持续性气候特征，并应用CoxStuart趋势分析法分析流域内极端持续性气候变化趋势，重点探讨TRMM降雨数据对持续性极端降雨情况的捕捉能力。所得结果如下：（1）时空精度分析表明TRMM在低纬度低海拔地区精度和准确性较好，而在高纬度且地形变化较大的地区则表现一般，容易出现虚报、误报现象；（2）持续极端气候方面，TRMM倾向于低估CWD及后汛期的RX5day，TRMM可捕捉到流域西部的持续干旱趋势，但难以捕捉到流域东南部持续性降雨显著增加的趋势。本研究所得结果可为流域内水资源管理和径流预测等提供一定科学依据，也可作为同纬度其他相似流域参考。 In recent years,the accuracy and applicability of TRMM satellite rainfall data have attracted much attention.In this study,we evaluated the TRMM data set over the Feilaixia catchment of the Beijiang river basin from 1998 to 2015 using gauged rainfall data from 24 stations. We first evaluated the accuracy of the TRMM at daily scale by using eight statistical performance indices.Then we used three consecutive extreme indices,including consecutive dry days (CDD),consecutive wet days (CWD),and maximum consecutive 5day precipitation (RX5day), together with Cox-Stuart test method to explore the extreme consecutive climate and its trends in the catchment,with special focus on the ability of TRMM in capturing consecutive extreme rainfall.The results revealed that (1) TRMM had better precision and accuracy in regions with low latitude and low altitude,but in regions with high latitude and large topographic changes,it performed poorly and was prone to false alarms and errors.(2) TRMM tended to underestimate CWD and RX5day (in the post-flood period) and it could capture the consecutive drought trends in the western part of the catchment,but failed to capture the significant increase trends of consecutive rainfall in the southeastern part.The conclusions obtained in this study can provide a scientific basis for water resources management and runoff monitoring within the catchment,and can also be used as reference for catchments with similar latitudes. 广东省水利科技创新项目（201622）；广东省水资源节约与保护资金项目