多源降水信息在秦淮河流域洪水模拟中的应用

目前天气雷达测雨与卫星遥感降水具有高时空分辨率与大面积的覆盖范围等特点,为洪水模拟预报提供了新的数据支持,但此类降水产品的预报能力差别较大,因此需对其进行精度评估。结合地面雨量站观测数据,在中纬度秦淮河下游流域定量评估S波段雷达测雨和全球高分辨率卫星CMORPH,Era-Interim,GPM和TRMM(3B42V7)降水数据的精度,并采用三水源新安江模型对选定的3场洪水过程进行了模拟。结果表明:在洪水过程径流模拟中,S波段雷达测雨数据与4种卫星降水产品均具有较好的径流模拟适用性;除雨量站外,精确度最高为S波段雷达和GPM,是当前评估中最好的降水产品,径流模拟精度达到0.92以上,且两种降水产品的趋势一致,其次是TRMM(3B42V7),Era-Interim,CMORPH卫星降水数据。研究成果可为天气雷达与常用卫星遥感降水数据在流域洪水模拟的水文预报应用提供参考与借鉴。

Application of multi-source rainfall information in flood simulation of Qinhuai River Basin

The quantitative precipitation estimated from weather radar and satellite remote sensing techniques can provide alternative rainfall observation data for hydrological simulation and flood forecasting due to the high spatial-temporal resolution and large-area coverage characteristics. However, the reliability and accuracy of such precipitation products varies, thus, the accuracy assessment needs to be conducted in advance. In this study, the rainfall products obtained from S-band weather radar and the high-resolution satellites, including CMORPH, Era-Interim, GPM, and TRMM (3B42V7) were compared and evaluated with the rainfall station data and three floods in Qinhuai River basin were simulated by using the Xin’anjiang hydrologic model. The results show that: the S-band radar rainfall estimates and four satellite precipitation products are suitable for runoff simulation; the rainfall products derived from S-band radar and GPM outperformed other rainfall products, with the average Nash-Sutcliff coefficient of 0.92, followed by TRMM (3B42V7), Era-Interim, and CMORPH satellite precipitation data. The trends of hydrographs derived from the S-band radar and GPM rainfall products are consistent with each other. This study can provide reference for the application of weather radar and common satellite precipitation data in hydrological forecasting of watershed flood.