Hydrological evaluation of hourly merged satellite-station precipitation product in the mountainous basin of China using a distributed hydrological model

Over the past two decades, various satellite-based precipitation products have been released to provide uninterrupted time-series precipitation with quasi-global coverage. The latest Chinese merged satellite-gauge (CMS) rainfall product developed by the China Meteorological Administration (CMA) may reduce the errors in near real time by combining the Climate Prediction Centre's (CPC) morphing algorithm (CMORPH) rainfall estimates with over 30,000 weather station measurements, which therefore offer a potential alternative or supplement to ground-based rainfall estimates for hydrometeorological applications in sparsely gauged or ungauged basins. In the present study, the characteristics of the CMS precipitation product were comprehensively evaluated for the period 2008-2012 over Danjiangkou basin, central China, and used to drive the Liuxihe (LXH)-distributed hydrological model for detailed streamflow simulations. The results show that most of the small-median rainfall with an intensity < 25 mm center dot day(-1) can be well captured by the CMS, and the simulated streamflow had relatively better agreement with observations for peak flow in the lower part of the basin. However, the total water amount was 15.7% less than the streamflow driven by rain gauges, on average. In addition, the depths of surface flow and groundwater forced by the CMS rainfall were 22.05% and 21.10% less than rain gauge, respectively. Overall, the study provides new insight into and experience of the hydrological applicability of the high spatiotemporal-resolution satellite-gauge rainfall product for driving a distributed hydrological model at a daily resolution. This product has the potential to be an alternative data source for data-sparse or ungauged basins for water resource management and hydrological simulation/prediction purposes.