Seasonal rainfall variability and its correlation with potential drivers over Western Oromia


  • kefiyalew Ayele Alandu NMA of Ethiopia
  • Tadesse Terefe Zeleke
  • Mesfin Asfaw Afrassa





Climate Change, Climate Variability, Rainfall Anomaly, SST, SLP, Sunspot.


Characterizing seasonal rainfall and identifying its association with the climate drivers are important to produce reliable seasonal climate forecasts of a given area. This study examined the rainfall variability and its relationships with SST, SLP and sunspot indices by statistical methods over Western Oromia. The regional is characterized by monomodal pattern of 60% seasonal rainfall contribution in Kiremt season. High temporal anomaly rainfall but no extremes were observed from 1981-2017. An insignificant decreasing Kiremt and Belg but, an increasing Bega trend was observed. ENSO and PDO/ DMI and AMO showed negative/ positive correlation with kiremt rainfall. ENSO, DMI and AMO showed positive correlation for belg rainfall whereas, PDO showed associated negatively for the most parts of the region. PSI to kiremt/Belg rainfall correlation showed significant positive/Negative spatial association over the western part (West Wolega and Illubabor) / the East part (Jimma & East wollega) of the region. The results showed that there is decreasing trends in rainfall anomalies for main rainy seasons of region and good correlations these various indices. Therefore, it is suggested that seasonal climate predictions may consider these large-scale determinants oscillation indices like AMO and PDO in predicting climatic events.




[1] Ayele et al. (2020) Seasonall Rainfall Variablity in Ethiopia and Its Long-Term Link to Global Sea Surface. Water 12(55); doi: 10.33900/w12010055.

[2] Admassu, S. (2006) Analysis of rainfall trend in Ethiopia. Eth J.Sci & Technol.3 (2), 15-30.

[3] Bezu, A.(2020) Analyzing Impacts of Climate variability and Changes in Ethiopia: A review. American Journal of Modern Energy, 6(3), 65-76.

[4] Daba, M. H. (2018). Agro Climatic Characterization in the Selected Woredas of Western Oromia, Ethiopia. Journal of Earth Science & Climatic Change, Vol 9(3).

[5] Daniel G, D. R. (2019). Does the IOD Independently Influence Seasonal Monsoon Patterns in Northern Ethiopia? Atmosphere, 10, 432.

[6] Diro G., G. D. (2011). Teleconnections between Ethiopian summer rainfall and sea surface temperature. Part II. Seasonal forecasting. Clim. Dyn., 37, 121–131.

[7] Egor, A. O. (2015). Inter-Annual Variability of Rainfall in Some States of Southern Nigeria. International Journal of Scientific & Technology Research (4), 2277-8616.

[8] Fahey, D. S. (2017). Physical drivers of climate in: Climate Science Special Report: Fourth National Climate Assessment, Volume I. Washington, DC, USA: U.S. Global Change Research Program.

[9] Friederike E L Otto, P. W. (2018). Anthropogenic influence on the drivers of the Western Cape drought 2015–2017. Environ. Res. Lett. 13, 124010.

[10] Gissila, T. B. (2004). Seasonal forecasting of the Ethiopian summer rains. Int. J. Climatol, 24, 1345–1358.

[11] Golian, H. R. (2015). Assessing the correlation between climate signals and monthly mean and extreme precipitation and discharge of Golestan Dam Watershed. Eart Sci. Res. J. Vol. 19, No. 1, 65 - 72.

[12] Gummadi et al.(2017) Spatio-temporal variability and trends of precipitation and extreme rainfall events in Ethiopiain1980-2010. Theoretical and Applied Climatology.

[13] Jestinos Mzezewa, T. M. (2010). Characterisation of rainfall at a semi-arid ecotope in the Limpopo Province (South Africa) and its implications for sustainable crop production. Water SA, vol.36 n.1, vol.36 n.1.

[14] Nath, M. A. (2015). Study on Rainfall Probability Analysis at Allahabad District of Uttar Pradesh. Journal of Biology, Agriculture and Healthcare, Vol.5, No.11.

[15] Segele Z., L. P. (2009). Large-scale atmospheric circulation and global sea surface temperature associations with Horn of Africa June–September rainfall. Int. J. Climatol., 29, 1075-1100.

[16] Shanko, D. &. (1998). The effects of the Southwest Indian Ocean tropical cyclones on Ethiopian drought. Int. J. Climatol., 18, 1373–1388.<1373::AID-JOC313>3.0.CO;2-K.

[17] Viste et al (2012) Recent Drought and Precipitation tendencies in Ethiopia. Theoretical and Applied

[18] Willems, C. O. (2015). Spatial and temporal variability of rainfall in the Nile Basin. Hydrol. Earth Syst. Sci., 19, 2227–2246.

[19] Yirgaw, D. G. (2011). Climate variability in the drought prone regions of Northern Ethiopia. Göteborg: Göteborg University, Sweden.

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