Evaluation of Satellite-based Rainfall Estimates for the Upper Blue Nile Basin

Abstract

Water resources planning and management are generally based on precipitation data. In the Nile Basin, conventional rain gauges are normally sparse, and hence, satellite-based rainfall estimates have become vital for hydrometeorological studies in the basin. However, estimates from satellite rainfall products are prone to bias and need to be validated in this region. In this study, four widely used high-resolution products (TRMM-3B42-RT, PERSIANN-CCS, GSMAP, and CHIRPS-V2) were evaluated against monthly ground observations from 44 stations over the Upper Blue Nile Basin during the period (2003-2013). The evaluation process is based on several standard statistical criteria to assess the ability of both satellite products and bias correction methods to capture the rainfall characteristics of this area. The results show that rainfall estimates from CHIRPS have a more reliable agreement with ground measurements than other products, especially in the wet season. The findings demonstrate the importance of assessing and correcting the outputs of different satellite rainfall products to be used for various hydrological applications in the Nile Basin.