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Observed changes in rainfall amount and extreme events in southeastern Ethiopia, 1955–2015

Theoretical and Applied Climatology volume 144, pages 967–983 (2021)Cite this article

Abstract

This study analysed spatio-temporal variability and trends in rainfall amount and extreme events in the southeastern part of Ethiopia for the period 1955–2015. Daily rainfall data from 44 recording stations were used to define total rainfall amounts and 12 extreme event indices for three wet seasons and annual time scale. Mann–Kendall’s trend test and Sen’s slope estimator were used to determine trends and rates of change, respectively. Results showed the emergence of different trend signals across seasons and over space in the study area. Trend tests for total rainfall amount and extreme indices for annual and March–May season show a global significant downward tendency. However, the number of wet and dry days, maximum consecutive wet and dry spells and wet day rainfall intensity for the annual time scale show mixed significant upward and downward tendencies, while trends for the number of dry days and maximum consecutive dry spells showed a global significant increasing trend for the March–May season across the study area. On the other hand, mixed global significant upward and downward tendencies were found in all rainfall indices for the June–September season over the northern part of the study area. Different from the two wet seasons, the trend test for the September–November wet season in the southern part of the study area shows an increasing tendency, although only few of the upward trends were statistically significant. In contrast, the number of dry days and maximum dry spell length for this season reveal decreasing trends at most of the stations. Empirical evidences generated in rainfall trends using dense gauging stations provide useful information to develop spatially relevant climate change adaptation and climate risk management plans.

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Data availability

We have all the raw, processed data and result products, and if it is required, we can provide the processed data and documents. However, the National Meteorological Agency does not allow us to provide raw precipitation data.

Code availability

The codes used to generate extreme precipitation indices are available, and we can submit if these codes are needed in any circumstances. Similarly, we used the MAKESENS Microsoft Excel add-in software, which is an open source to generate trend magnitude and patterns, and we can make it available if it is needed.

References

  • ACPC (African Climate Policy Centre) (2013) Africa’s climate observing networks: challenges, needs and recommendations. Policy Briefs. The United Nations Economic Commission for Africa (ECA), Addis Ababa

  • Bewket W, Conway D (2007) A note on the temporal and spatial variability of rainfall in the drought-prone Amhara Region of Ethiopia. Int J Climatol 27:1467–1477. https://doi.org/10.1002/joc.1481

    Article  Google Scholar 

  • Billi P, Alemu YT, Ciampalini R (2015) Increased frequency of flash floods in Dire Dawa, Ethiopia: change in rainfall intensity or human impact? Nat Hazards 75:1373–1394. https://doi.org/10.1007/s11069-0141554-0

    Article  Google Scholar 

  • Block PJ (2008) Mitigating the effects of hydrologic variability in Ethiopia: an assessment of investments in agricultural and transportation infrastructure, energy, and hydroclimatic forecasting. CPWF Working Paper 01 The CGIAR Challenge Program on Water and Food, Colombo, Sri Lanka. 53pp

  • Burn DH, Sharif M, Zhang K (2010) Detection of trends in hydrological extremes for Canadian watersheds. Hydrol Process 24:1781–1790. https://doi.org/10.1002/hyp.7625

    Article  Google Scholar 

  • Cheung WH, Senay G, Singh A (2008) Trends and spatial distribution of annual and seasonal rainfall in Ethiopia. Int J Climatol 28:1723–1734. https://doi.org/10.1002/joc.1623

    Article  Google Scholar 

  • Conway D, Mould C, Bewket W (2004) Over one century of rainfall and temperature in Addis Ababa, Ethiopia. Int J Climatol 24:77–91. https://doi.org/10.1002/joc.989

    Article  Google Scholar 

  • Conway D, Persechino A, Syroka J (2007) Reducing vulnerability in Ethiopia: addressing the implications of climate change. Drought risk financing in Ethiopia: technical assessment of indicators used for contingency financing mechanisms. University of East Angelia, Overseas Development Group, 39 p

  • Conway D, Schipper ELF (2011) Adaptation to climate change in Africa: challenges and opportunities identified from Ethiopia. Glob Environ Chang 21:227–237. https://doi.org/10.1016/j.gloenvcha.2010.07.013

    Article  Google Scholar 

  • Degefu MA, Bewket W (2017) Variability, trends, and teleconnections of stream flows with large-scale climate signals in the Omo-Ghibe River Basin, Ethiopia. Environ Monit Asses 189:142. https://doi.org/10.1007/s10661-017-5862-1

  • Degefu MA, Alamirew T, Zeleke G, Bewket W (2019) Detection of trends in hydrological extremes for Ethiopian watersheds, 1975–2010. Reg Environ Chang 19:1923–1933. https://doi.org/10.1007/s10113-019-01510-x

    Article  Google Scholar 

  • Degefu MA, Bewket W (2014) Variability and trends in rainfall amount and extreme event indices in the Omo-Gibe River Basin, Ethiopia. Reg Environ Chang 14:799–810. https://doi.org/10.1007/s10113-013-0538-z

    Article  Google Scholar 

  • Degefu MA, Rowell PD, Bewket W (2017) Teleconnections between Ethiopian rainfall variability and global SSTs: observations and methods for model evaluation. Meteorol Atmos Phys 129:173–186. https://doi.org/10.1007/s00703-016-0466-9

    Article  Google Scholar 

  • FAO (Food and Agricultural Organization) (2010) Agricultural based livelihood systems in dry lands in the context of climate change: inventory of adaptation practices and technologies of Ethiopia, ISBN 978-92-5-106664-5

  • Few R, Tebboth MGL (2018) Recognising the dynamics that surround drought impacts. J Arid Environ 157:113–115. https://doi.org/10.1016/j.jaridenv.2018.06.001

    Article  Google Scholar 

  • Funk C, Dettinger MD, Michaelsen JC, Verdin JP, Brown ME, Barlo M, Hoel A (2008) Warming of the Indian Ocean threatens eastern and southern African food security but could be mitigated by agricultural development. Proceeding of National Academy of Sciences of the USA 105:11081–11086.https://doi.org/10.1073/pnas.0708196105

  • Gamachu D (1988) Some patterns of altitudinal variation of climatic elements in the mountainous regions of Ethiopia. MT RES DEV 8:131–138. https://doi.org/10.2307/3673439

    Article  Google Scholar 

  • IPCC WK II (2014). Climate change 2014 synthesis report summary for policymakers. Cambridge University Press: Cambridge, Uk

  • Khaliq MN, Ouardab TBMJ (2007) On the critical values of the standard normal homogeneity test (SNHT). Int J Climatol 27:681–687. https://doi.org/10.1002/joc.1438

    Article  Google Scholar 

  • Kundzewicz ZW, Graczyk D, Maurer T (2005) Trend detection in river flow series: 1. Annual maximum flow. HydrolSci J 50:797–810. https://doi.org/10.1623/hysj.2005.50.5.797

    Article  Google Scholar 

  • Mekasha A, Tesfaye K, Duncan AJ (2014) Trends in daily observed temperature and precipitation extremes over three Ethiopian ecoenvironments. Int J Climatol 34:1990–1999. https://doi.org/10.1002/joc.3816

    Article  Google Scholar 

  • Mengistu D, Bewket W, Rattan L (2014) Recent spatio-temporal temperature and rainfall variability and trends over the upper Blue Nile River Basin, Ethiopia. Int J Climatol 34:2278–2292. https://doi.org/10.1002/joc.3837

    Article  Google Scholar 

  • Meze-Hausken E (2004) Contrasting climate variability and meteorological drought with perceived drought and climate change in northern Ethiopia. Clim Res 27:19–31

    Article  Google Scholar 

  • Ng’ang’a SK, Van Wijk MT, Rufino MC, Giller KE (2016) Adaptation of agriculture to climate change in semi-arid Borena, Ethiopia. Reg Environ Chang 16:2317–2330. https://doi.org/10.1007/s10113-016-0940-4

    Article  Google Scholar 

  • Osman M, Sauerborn P (2002) A preliminary assessment of characteristics and long-term variability of rainfall in Ethiopia basis for sustainable land use and resource management. In Paper Presented At Conference on International Agricultural Research for Development, Witzenhausen, Germany, Oct 9–11:2002

    Google Scholar 

  • Pantuliano S, Wekesa M (2008) Improving drought response in pastoral areas of Ethiopia Somali and Afar Regions and Borena Zone of Oromiya Region. Humanitarian Policy Group Overseas Development Institute, London

    Google Scholar 

  • Petrow T, Merz B (2009) Trends in flood magnitude, frequency and seasonality in Germany in the period 1951–2002. J Hydrol 371:129–141. https://doi.org/10.1016/j.jhydrol.2009.03.024

    Article  Google Scholar 

  • Rettberg S (2010) Contested narratives of pastoral vulnerability and risk in Ethiopia’s Afar region. Pastoralism 1:248–273

    Google Scholar 

  • Rosell S, Holmer B (2007) Rainfall change and its implications for Belg harvest in South Wollo, Ethiopia. Geogr Ann 89(4):287–299

  • Salmi T, Määttä A, Anttila P, Ruoho-Airola T, Amnell T (2002) Detecting trends of annual values of atmospheric pollutants by the Mann-Kendall test and Sen’s slope estimates: the excel template application MAKESENS. Finnish Meteorological Institute, No. 31

  • Segele Z, Lamb PJ, Leslie LM (2009) Seasonal-to-interannual variability of Ethiopia/Horn of Africa monsoon. Part I: associations of Wavelet-Filtered large-scale atmospheric circulation and global sea surface temperature. J Climate 22:3396–3421. https://doi.org/10.1175/2008JCLI2859.1

    Article  Google Scholar 

  • Seleshi Y, Camberlin P (2006) Recent changes in dry spell and extreme rainfall events in Ethiopia. Theor Appl Climatol 83:181–192. https://doi.org/10.1007/s00704-005-0134-3

    Article  Google Scholar 

  • Seleshi Y, Zanke U (2004) Recent changes in rainfall and rainy days in Ethiopia. Int J Climatol 24:973–983. https://doi.org/10.1002/joc.1052

    Article  Google Scholar 

  • Shang H, Yan J, Gebremichael M, Ayalew SM (2011) Trend analysis of extreme precipitation in the northwestern highlands of Ethiopia with a case study of Debre Markos. Hydrol Earth Syst Sci 15:1937–1944. https://doi.org/10.5194/hess-15-1937-2011

    Article  Google Scholar 

  • Verdin J, Funk C, Senay G, Choularton R (2005) Climate science and famine early warning. Phil Trans R Soc B 360:2155–2168. https://doi.org/10.1098/rstb.2005.1754

    Article  Google Scholar 

  • Viste E, Korecha D, Sorteberg A (2013) Recent drought and precipitation tendencies in Ethiopia. Theor Appl Climatol 112:535–551. https://doi.org/10.1007/s00704-012-0746-3

    Article  Google Scholar 

  • Wang Y, Quan Q, Shen B (2019) Spatio-temporal variability of drought and effect of large scale climate in the source region of Yellow River. Geomat. Nat Haz Risk 10:678–698. https://doi.org/10.1080/19475705.2018.1541827

    Article  Google Scholar 

  • WMO (World Meteorological Organization) (2009) Guidelines on: analysis of extremes in a changing climate in support of informed decisions for adaptation. Climate Data and Monitoring WCDMP-No. 72

  • World Bank (2006) Ethiopia: managing water resources to maximize sustainable growth. World Bank, DC 20433, Washington D.C

  • Yue S, Pilon P, Phinney B, Cavadias G (2002) The influence of autocorrelation on the ability to detect trend in hydrological series. Hydrol Process 16:1807–1829. https://doi.org/10.1002/hyp.1095

    Article  Google Scholar 

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Acknowledgements

We are very grateful to the Ethiopian National Meteorological Agency (NMA) for providing us with the daily rainfall data used for this study. We also thank the Dire Dawa University for the financial support to the first and second authors.

Funding

This study was funded by the Dire Dawa University. There was no agreement number.

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Authors and Affiliations

  1. Department of Geography & Environmental Studies, Debre Markos University, P.O. Box 269, Debre Markos, Ethiopia

    Mekonnen Adnew Degefu

  2. Department of Geography & Environmental Studies, Dire Dawa University, P.O. Box 1362, Dire Dawa, Ethiopia

    Yonas Tadesse

  3. Department of Geography & Environmental Studies, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia

    Woldeamlak Bewket

Authors
  1. Mekonnen Adnew Degefu
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  2. Yonas Tadesse
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  3. Woldeamlak Bewket
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Contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Mekonnen Adnew Degefu and Yonas Tadesse. The first draft of the manuscript was written by Mekonnen Adnew Degefu. Yonas Tadesse and Woldeamlak Bewket reviewed and commented on the first draft of the manuscript. Woldeamlak Bewket has supervised the research work. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Mekonnen Adnew Degefu.

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The submission is the independent work of the authors. It has not been submitted and not published or accepted for publication and is not under consideration for publication in another journal or book. The submission has been approved by all relevant authors, and all persons entitled to authorship have been so named. All authors have seen and agreed to the submitted version of the manuscript.

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Degefu, M.A., Tadesse, Y. & Bewket, W. Observed changes in rainfall amount and extreme events in southeastern Ethiopia, 1955–2015. Theor Appl Climatol 144, 967–983 (2021). https://doi.org/10.1007/s00704-021-03573-5

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