Evaluation of TRMM 3B42V7 at the basin scale over mainland China

This study evaluated the accuracy and consistency of TRMM rainfall at basin scale across China over the period of 1998 to 2013 based on gauged daily rainfall from 2 257 meteorological stations. The detection accuracy indices (POD, FAR, ACC, and CSI), Pearson correlation coefficient (PCC), and relative error were used. The results show that: ① Detection accuracy of daily TRMM rainfall events decreases from southeast coast to northwest inland in general; ② Average annual rain days from gauged rainfall is significantly larger than that of TRMM; ③ There is a good relation between monthly/annual gauge rainfall and TRMM rainfall at all stations, except for the stations in Northwest China; ④ Average annual rainfall estimated from TRMM is higher than that of the gauged rainfall in all basins, especially in the Southwest China. Relative error of monthly areal TRMM rainfall is smaller in the rainy season and larger in dry season; ⑤ Trends of annual areal TRMM rainfall is in agreement with that of annual areal gauge rainfall in all basins. Annual rainfall demonstrates a decreasing trend in the basins in southern China, and an increasing trend in the basins in northern China. As a result, the annual rainfall overall China shows a slight decreasing trend from 1998 to 2013.