Characterization of Past Seasonal Climate Variability in Oromia Special Zone, North Eastern Ethiopia

摘要

This study was undertaken in oromia special zone of Amhara National Regional State to analyze past climate variability. Gridded climate data were obtained from National Meteorology Agency of Ethiopia. Standard stastical descriptors and statistical software like Instat V3.37, MAKESENS, XLSTAT 2014 and Arc GIS 10.1 were employed for the analysis and interpretation for results. The results indicated that the OSZ experienced moderate rainfall variability in kiremt (JJAS) season and very high variability in belg (FMAM) season . Increasing trend in kiremt rainfall while decreasing trend in belg rainfall. Except belg minimum temperature, also temperature trend increased. The median of the start of belg season did not between March and May. The risk of getting 5,7,10 and 15 days of dry spells based on the fitted first order Markov chain probability values indicate in belg season the probability of dry spell occurrence of 10 days’ length was 60%. In kiremt season, the dry spell risk of being greater than10 day consecutive dry spells was less than 50%, and it is expected to occurred beteewen 178 DOY (June 26) to 262 DOY (Sept 18). District level of upcoming season climate information in terms of climate variability and encourage farmers to benefit from these services, apply adaptation and mitigation strategy are important for reduce the challenges of cropping practices in the study area.