Accuracy of integrated multi-satellie retrievals for gpm satellite rainfall product over North Vietnam

Abstract

Remote sensing of precipitation has been paid attention to recently for improving water resources estimation and hydrological applications. This study aims to assess one of the latest satellite rainfall product – Integrated Multi-satelliE Retrievals for GPM (IMERG) for Northern Vietnam. This study used the Tropical Rainfall Measurement Mission (TRMM), which is the predecessor of IMERG as a benchmark. The work consists of two parts: (i) comparison of IMERG and TRMM with rain gauge at a daily time scale; (ii) simulation of daily streamflow with IMERG-based and TRMM-based hydrological models. Four different precipitation metrics have been used to evaluate the IMERG and TRMM datasets, and the Soil and Water Assessment Tool (SWAT) hydrological model has been used in simulating daily streamflow at two river basins. The results indicated that IMERG did not significantly improve than TRMM when compared them with rain gauge. However, IMERG-based SWAT models were comparable with rain-gauge-based SWAT models in simulating daily streamflow. The TRMM-based SWAT models only produced reasonable results at one basin. Overall, the IMERG rainfall dataset can be an alternative rainfall dataset for Northern Vietnam with respect to estimated rainfall as well as input for hydrological simulation. This study provides useful information for environmental assessment, water resources management, and decision-making with support of remote sensing datasets.