Quantification of Gridded Precipitation Products for the Streamflow Simulation on the Mekong River Basin Using Rainfall Assessment Framework: A Case Study for the Srepok River Subbasin, Central Highland Vietnam

Many fields have identified an increasing need to use global satellite precipitation products for hydrological applications, especially in ungauged basins. In this study, we conduct a comprehensive evaluation of three Satellite-based Precipitation Products (SPPs): Integrated Multi–satellitE Retrievals GPM (IMERG) Final run V6, Soil Moisture Rain (SM2RAIN)-Advanced SCATterometer (ASCAT) V1.5, and Multi-Source Weighted-Ensemble (MSWEP) V2.2 subbasin the Mekong River Basin (MRB). The study area Srepok basin (SRB) represents Central Highland sub-climatic zone Vietnam under impacts newly built reservoirs during 2001–2018. our was performed using Rainfall Assessment Framework (RAF) with two separated parts: (1) intercomparison rainfall characteristics between rain gauges SPPs; (2) comparison simulated streamflow driven by SPPs gauges. Several key findings are: IMERGF-V6 shows highest performance compared other SPP products, followed SM2RAIN-ASCAT V1.5 MSWEP over assessments RAF framework; discrepancies dry wet seasons, exhibiting very low correlation when intensity is greater than 15 mm/day; (3) SM2RAIN–ASCAT ranked as second best SPP, after IMERGF-V6, good simulation, but overestimates seasonal underestimates rainfall, 20 mm/day, suggesting recalibration validation its algorithm; (4) had lowest bias score season, indicating product’s usefulness trend analysis drought detection; (5) evaluate reservoirs, framework similar studies. results are first reveal V1.5. Additionally, proposes new assessment which could support future studies selecting suitable input into model simulations regions.