Abstract

The trend analysis has been employed to inspect the change of rainfall and temperature in Dire Dawa city administration, using gauged monthly precipitation and Temperature data obtained from National meteorological Agency of Ethiopia from 1980 to 2014 and the future climate data of GCM used by the Intergovernmental Panel on Climate Change fifth generation CMIP5 and World Clim obtained from Agricultural Model inter-comparison and Improvement Project (AgMIP) website. Two models such as HadGEM2-ES and MRI-CGCM3 under rcp4.5and 8.5 have been considered to generate rainfall, maximum and minimum temperature data using AgMIP R script of “run_ agmip_simple_delta.R”in R software 3.5.3 version. Recent and future rainfall variability CV, Standard deviation and rainfall Anomaly have been computed using excel spreadsheet for variability analysis and the Mann-Kendall test was used to detect the time series trend of inter-seasonal to seasonal temperature and rainfall using R software version 3.5.3. The inter-seasonal to seasonal observed and projected rainfall data shown highly variable while the annual rainfall variability shown in moderate range of variability. The declining trend for belg and inclining trend of kiremt mean observed and HadGEM2-ES(CMIP5) under rcp8.5 model rainfall were found to be statistically significant while that of annual and other monthly trend were not significant except July in observed data but the other projected model for future rainfall trend shown no statistical significant. Therefore, the concerned bodies should take in to consideration climate change adaptation strategy and finally, it is recommended to extend farther study with Ensemble GCM model and RCM.

Keywords: Climate change; Mann-Kendall test; Seasonal rainfall; Trend analysis