Journal of Environmental Hazards

Downscaling Future Temperature and Precipitation Values in Kombolcha Town, South Wollo in Ethiopia

Abstract

Kasye Shitu* and Mengesha Tesfaw

Whilst climate change is already manifesting in Ethiopia through changes in temperature and rainfall, its magnitude is poorly studied at regional levels. Therefore, the main aim of this study was statistically downscale of future daily maximum temperature, daily minimum temperature, and precipitation value in Kombolcha Town, South Wollo, in Ethiopia. For this the long term historical climatic data were collected from Ethiopian National Meteorological Agency for Kombolcha station and the GCM data were downloaded from the global circulation models of, the Canadian Second Generation Earth System Model from the link (http://climate scenarios.canada.ca/?page=dstsdi). For future climate data generation among the different downscaling techniques, the statistical down scaling method, a type of regression model was used and the variations of temperature (maximum and minimum) and precipitation in the town for annually and seasonally condition were analysis based on the base of the 2020s, 2050s and 2080s. In the future, relative to the observed mean value of annual rainfall in Kombolcha town, mean value of annual rainfall will decrease 1.36% - 7.03% for RCP4.5and 5.37% -13.8% for RCP8.5 emission scenarios in the last 21 century. Both maximum and minimum temperature of the town will be increased in the future time interval for both RCP4.5 and RCP8.5 emission scenarios. The rise in temperature will exacerbate the town maximum heat effects in warm seasons and decrease in precipitation is expected along with a possible risk of water supply scarcity due to a low level of water supply access and a high rate of urbanization.