多源卫星降水数据在瓯江流域的适用性分析

为利用卫星降水数据开展流域水文模拟预报,基于瓯江流域内94个雨量站1998~2013年逐日降雨量数据,分析了多源卫星降水数据(TMPA、RT、CMORPH和PERSIANN)在该地区的适用性。结果表明,PERSIANN数据精度最低,其次为CMORPH和RT,TMPA数据精度最高,其中PERSIANN和CMORPH数据低估了实际降水量,而RT和TMPA略高估了降水量;梅汛期和非汛期的精度高于台汛期,月时间尺度降水量的精度高于日时间尺度。各卫星降水数据中,TMPA和RT数据在中雨级别下精度最高,对小雨和大雨级别的降水分别存在低估和高估现象,而PERSIANN和CMORPH数据对所有量级下的降水均存在低估现象;随着雨量的增加,卫星降水的误报率均有不同程度的增加。

Applicability Analysis of Various Satellite based Precipitation in Oujiang Basin

In order to utilize satellite precipitation data for basin hydrological forecasting, the applicability of various satellite precipitation data (TMPA, RT, CMORPH and PERSIANN) was estimated based on the daily precipitation data of 94 rainfall stations with the period of 1998 to 2013. The results show that the data precision of TMPA is the highest, followed by CMORPH, RT and PERSIANN. Among the four datasets, PERSIANN and CMORPH seem to possibly underestimate the precipitation while TMPA and RT slightly overestimate the rainfall. In general, the satellite based precipitation estimates agreed well with the gridded gauge data at monthly time scales, particularly for the Meiyu and non flood period. The TMPA and RT perform well for the medium precipitation thresholds, with overestimating and underestimating for the low and the storm thresholds. However, the satellite of PERSIANN and CMORPH tend to underestimate the rain events. With the increase of rainfall, misinformation rate of satellite precipitation data increase to a certain extent.