Hydrologie: Aktuelle Forschung

Climate Projection Outlook in Lake Haramaya Watershed, Eastern Ethiopia

Abstract

Eba Muluneh Sorecha

Smallholder farmers in Ethiopia generally face widespread problems driven by climate change. For this reason, the study of climate change at watershed level might be critical to solve the problem from its root. The study was conducted in Lake Haramaya Watershed, Eastern Ethiopia to project ad characterize the climatic condition of the coming thirty years (2020-2050). Thirty-four years of rainfall, maximum and minimum temperature baseline data were collected from National Meteorological Agency of Ethiopia. Whereas, thirty years (2020-2050) projected rainfall, maximum and minimum temperatures were downscaled from MarkSim web version for IPCC AR5 data (CMIP5) using five climate models namely: BCC-CSM1-1, CSIRO-Mk3-6-0, HadGEM2-ES, MIROC-ESM, MIROCESM- CHEM, and MIROC5 under two Representative Concentration Pathways (RCPs): RCP4.5 and RCP8.5. The results of the study revealed that the annual mean rainfall will be increased by 20.70 and 24.14% under RCP4.5 and RCP8.5, respectively compared to baseline average value of 777.51 mm/yr. The annual rainfall under RCP4.5 ranges from 769.6 to 1090 mm/yr having the CV value of about 11%; whereas, under RCP8.5, it will range from 771.9 to 1129 mm/yr with the CV value of 13.17%. Kiremt (JJAS) season rainfall will increase from the baseline of 107.55 mm/yr to 135.79 and 136.27 mm/yr under RCP4.5 and RCP8.5, respectively. Moreover, a study indicated that the annual and seasonal temperature under RCP4.5 and RCP8.5 will be expected to increase during 2020-2050 period. Under high emission scenario of RCP8.5, the annual maximum temperature could rise from 24.73°C baseline to 25.41°C.