Spatiotemporal Attribution and Trends of Climate Variables in Iluababora Zone, Oromia National Regional State, Ethiopia

Abstract

The environmental diversity associated climatic variables in the micro environments are anticipated to change over times. This study aimed to examine precipitation concentration and anomaly indices, and trends of climatic variables over micro-environments of Iluabbabora zone. Climatic data were obtained from NASA’s dataset, recorded from 1981–2018. Precipitation concentration indices were estimated and interpolated using an inverse distance weighting. The frequency and percentile of drier and wetter periods was analyzed using standardized precipitation anomaly index model. The Mann Kendall trend test was used to determine trends of seasonal and annual temperature and precipitation. Results show that both seasonal and annual precipitation concentrations were inconsistently distributed among the seasons and neighboring locations. A strong concentration index (23) was observed in Meko during summer season. Standardized precipitation anomaly indices Analyses indicated that the frequency and percentiles of the driest years were more pronounced than wettest periods in all locations. The higher percentage (55.41%) drier period above the normal was observed in Bedele followed by Birbisa (54.05%). Trends analyses of seasonal mean temperature and precipitation were inconsistently changed with respect to the seasons and locations. The spring minimum temperature of Bedele, winter minimum temperature of all locations and annual minimum temperature of Gore were significantly warmed (P>0.05). Similarly, the spring season of Birbisa, and Gore, winter summer seasons and annual maximum temperature of Bedele and Gore locations were significantly increased (P<0.05) whereas the spring and summer seasons of Bedele, annual and summer season precipitation of Gore were significantly decreased (P<0.05). Therefore, the study confirmed that variability and change of climatic variables in different micro environments were rapidly and indifferently tracked toward severe climatic shocks, and suggesting that sound implementations of existing forest protection and soil water conservations in the study area.