Assessment of the Potential Impacts of Climate Change in Agricultural Catchment: The Case of Fincha, North western Ethiopia

Abstract

The relevance of agriculture to the promotion of sustainable development largely depends on the availability of water resources. Climate change  affects water resource by altering the magnitude and patterns of hydrological process. This study was aimed at evaluating the potential impacts of  climate change on hydrological process of Fincha catchment, upper Blue Nile basin. The ensemble mean of regional climate models (RCMs) in  coordinated regional climate downscaling experiment (CORDEX)-Africa was used based on high emission scenario (RCP8.5) and medium emission  scenario (RCP4.5). Soil and Water Assessment tool (SWAT) hydrological modeling was used to evaluate the impacts of climate change. The result  shows a decreasing precipitation by -8.24% to - 11.32% under RCP4.5 and -7.87% to -9.67% under RCP8.5 in 2021-2050 and 2051-2080, respectively.  The temperature will increase under both RCPs. The decline of precipitation and increase of temperature reduces surface flow, groundwater and  water yield. The increase in Evapotranspiration due to increased temperature and higher evaporation demands coupled with a decreasing  precipitation leads to a reduced soil moisture. This could reduce the availability of water for crop production, which will be a chronic issue to the  subsistence agriculture. The increase in seasonal and annual variation of precipitation and temperature increased the frequency of hot and dry  years that will lead to serious water scarcity that aggravate water stress in the catchment and further downstream. Consequently, strong mitigation  and adaptation through land and water management by coping with water scarcity in agriculture and water productivity is indispensable to manage  the risks.