Impact of Rainfall Variability on Shabelle River Basin

Abstract

The Shabelle River is a crucial water source for Somalia’s Hiiran and Middle Shabelle regions, yet its flow dynamics are largely governed by rainfall variability in upstream Ethiopia. This study analyzes long-term meteorological, hydrological, and remote sensing data to assess precipitation trends and their influence on the river’s seasonal discharge. Results show that Somali rainfall contributes less than 5% to total river flow, highlighting the dominant role of Ethiopian catchments. However, upstream irrigation development poses severe risks, with projections indicating up to an 80% reduction in river flow by 2035 compared to 2005 levels. These findings underscore the urgent need for sustainable transboundary water management to mitigate drought, secure livelihoods, and ensure long-term water availability in the basin.