Climate change impact on stream flow in the upper gilgel abay catchment, blue nile basin, Ethiopia
Book Chapter
Adem, AA, Tilahun, SA, Ayana, EK et al. (2015). Climate change impact on stream flow in the upper gilgel abay catchment, blue nile basin, Ethiopia
. 645-673. 10.1007/978-3-319-18787-7_29
Adem, AA, Tilahun, SA, Ayana, EK et al. (2015). Climate change impact on stream flow in the upper gilgel abay catchment, blue nile basin, Ethiopia
. 645-673. 10.1007/978-3-319-18787-7_29
According to Intergovernmental Panel on Climate Change (IPCC) future projections, precipitation and temperature will increase over eastern Africa in the coming century. This chapter presents basin-level impact of climate change on stream flow in Upper Gilgel Abay catchment, Blue Nile basin, Ethiopia, by downscaling HadCM3 global climate model (GCM) using statistical downscaling model (SDSM). IPCC recommended baseline period (1961-1990) was used for analysis of baseline scenario. For future scenario analysis time periods of the 2020s, 2050s and 2080s were used. Globally, HadCM3 model is widely applied for climate change studies and it contains A2 (medium-high emission) and B2 (medium-low emission) scenarios. The impact assessment on stream flow was done using the soil and water assessment tool (SWAT) hydrological model. The performance of SWAT model in simulating the stream flow was shown with a Nash-Sutcliffe Efficiency (NSE) of 0.76 and 0.78 for calibration and validation periods, respectively. Mean annual changes of precipitation and temperature (maximum and minimum) were applied to quantify these impacts. The result of downscaled precipitation and temperature reveals a systematic increase in all future time periods for both A2 and B2 scenarios. These increases in climate variables are expected to increase mean annual stream flow by 7.1, 9.7, and 10.1 % for A2 scenario and by 6.8, 7.9, and 6.4 % for B2 scenario for 2020s, 2050s, and 2080s, respectively. Future work need to consider impact of land use change on the catchment for future sustainable development plan.
