Evaluation and hydrological simulation of different satellite precipitation products in Dadu River Basin

This study takes the Dadu River Basin as a case study to evaluate the data quality of two satellite-based precipitation products, CMORPH and IMERG, by comparing them with gauge-observed precipitation. Five experimental scenarios were designed to force the Xin'anjiang hydrological model in order to assess the applicability and uncertainty of these products in hydrological simulation and water resource estimation. The results indicate that both satellite products generally exhibit high quality with minimal overall deviation, although they tend to overestimate rainfall over most of the basin. Hydrological simulations driven by these two satellite-based precipitation products data exhibits lower accuracy compared to those using gauge-observed data, with considerable inter-annual variability and an overall inability to meet required precision standards. However, the accuracy of simulations significantly improves on a monthly scale, closely matching observed monthly hydrologic processes. These findings provide valuable insights for the application of satellite-based precipitation products in hydrology and water resources research.