干旱区生态环境知识资源中心

Satellite-based precipitation products are promising data sources for the hydrometeorological community. However, many of these products lack quantitative estimates of their uncertainty. In this paper, we present a thorough evaluation study of the state-of-the-art satellite-based precipitation product: Tropical Rainfall Measurement Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) research product (TRMM 3B42) in the middle and upper reaches of Heihe River Basin. The study area locates in arid and semiarid regions in the northwest of China. Both version 6 (V6) and the newly released version 7 (V7) TRMM 3B42 research products are evaluated through statistical analysis and hydrological modeling in this study. Wefind that the performance of daily TMPA products is climatology-dependent. For the study basin, TMPA products generally perform better in wetter than in drier climatology conditions. High False Alarming Ratio (FAR) and positive bias occur in drier areas, whereas TMPA products display negative bias in wetter regions. TMPA products perform worse in winter when snowfall occurs than in nonsnow seasons. The new V7 TMPA products perform better than V6 on both daily and monthly scales. Hydrological modeling results show that TMPA products are promising in streamflow simulation at ungauged basins in arid and semiarid regions, especially the new V7 whose integrated performance is comparable with that of gauge-based precipitation estimate. When model parameters’ sensitivity in forcing precipitation is considered by model recalibration, performances of both two versions of TMPA products are improved, especially for the peak flow simulation in summer. This study can serve as a reference of uncertainty estimates of the TMPA research time precipitation products in hydrometeorological applications at a watershed scale.