
The characteristics of hydro-meteorological changes in the Gilgel Gibe River Basin were analyzed based on the recorded data collected for a period greater than 25 years at 5 weather stations for rainfall, 3 stations for maximum and minimum temperature and 2 hydrological stations for streamflow. A non parametric trend test for monthly data shows an increasing trend for rainfall and temperature. The monthly streamflow recorded at 2 gauging stations has also indicated an increasing trend. The impact of climate change on the streamflow for the future period of the 2011 – 2040 was also assessed by using the Soil and Water Assessment Tool (SWAT) hydrological model using downscaled precipitation and temperature data obtained from ECHAM5 and HadCM3 model projections. The increase in streamflow of the past records can be partly explained by the climate change. The impact of climate change in the future period of 2011 – 2040 will slightly increase the streamflow of Gilgel Gibe 1 River.