Extreme precipitation events pose significant challenges to water resources, agriculture, infrastructure, public health, ecosystems, energy production, fishing, timber production, and other rain-dependent socioeconomic sectors across Eastern Africa, threatening the environment and regional livelihoods. This study analyzes spatial and temporal trends of extreme precipitation in Eastern Africa from January 1981 to 2023, using high-resolution CHIRPS data. Key extreme precipitation indices, including R10mm, R75p, and SDII, were calculated to assess variations in the frequency, intensity, and contribution of extreme rainfall events. The temporal analysis reveals a statistically significant increasing trend in January precipitation (0.844 mm/year, p = 0.0191), confirmed by Sen’s Slope (0.74 mm/year). R10mm increased by 0.036 days/year (p = 0.0079), with Sen’s Slope estimating 0.04 days/year. R75p showed a rise of 0.025 days/year (p = 0.0113), with Sen’s Slope at 0.02 days/year. SDII exhibited the most significant trend, increasing by 0.056 mm/day per year (p = 0.0002), with Sen’s Slope at 0.06 mm/day per year. These results indicate a rise in extreme precipitation in Eastern Africa, increasing the risk of flooding and other climate-related hazards. Spatial analysis shows distinct regional variations, with Southern Tanzania, Mozambique, Malawi, Zambia, Zimbabwe, and Madagascar exhibiting statistically significant increasing trends in January precipitation and extreme precipitation indices. These regions are becoming more vulnerable to flooding and other climate-related hazards. Moreover, correlation analysis identifies significant links between global SST anomalies and extreme precipitation trends, demonstrating the influence of large-scale climate drivers. The study indicates the growing intensity and frequency of extreme precipitation in parts of Eastern Africa, significantly influenced by the South Pacific Convergence Zone (SPCZ). This necessitates a deeper understanding of SPCZ dynamics and their impacts on precipitation patterns to enhance climate prediction and develop adaptive strategies for mitigating extreme weather events. Such efforts will contribute to safeguarding water resources, agriculture, infrastructure, public health, energy production, fisheries, transportation, and livelihoods across the region.
References
[1]
Allan, R. P., Soden, B. J., John, V. O., Ingram, W., & Good, P. (2010). Current Changes in Tropical Precipitation. Environmental Research Letters, 5, Article 025205. https://doi.org/10.1088/1748-9326/5/2/025205
[2]
Anyah, R. O., & Semazzi, F. H. M. (2004). Simulation of the Sensitivity of Lake Victoria Basin Climate to Lake Surface Temperatures. Theoretical and Applied Climatology, 79, 55-69. https://doi.org/10.1007/s00704-004-0057-4
[3]
Ayugi, B., Jiang, Z., Iyakaremye, V., Ngoma, H., Babaousmail, H., Onyutha, C. et al. (2022). East African Population Exposure to Precipitation Extremes under 1.5˚C and 2.0˚C Warming Levels Based on CMIP6 Models. Environmental Research Letters, 17, 044051. https://doi.org/10.1088/1748-9326/ac5d9d
[4]
Cai, X., Zhang, X., Noël, P. H., & Shafiee-Jood, M. (2015). Impacts of Climate Change on Agricultural Water Management: A Review. WIREs Water, 2, 439-455. https://doi.org/10.1002/wat2.1089
[5]
Camberlin, P. 2018. Climate of Eastern Africa. In Oxford Research Encyclopedia of Climate Science . Oxford University Press. https://doi.org/10.1093/acrefore/9780190228620.013.512
[6]
Camberlin, P., & Okoola, R. E. (2003). The Onset and Cessation of the “Long Rains” in Eastern Africa and Their Interannual Variability. Theoretical and Applied Climatology, 75, 43-54. https://doi.org/10.1007/s00704-002-0721-5
[7]
Chang’a, L. B., Kijazi, A. L., Mafuru, K. B., Nying’uro, P. A., Ssemujju, M., Deus, B. et al. (2020). Understanding the Evolution and Socio-Economic Impacts of the Extreme Rainfall Events in March-May 2017 to 2020 in East Africa. Atmospheric and Climate Sciences, 10, 553-572. https://doi.org/10.4236/acs.2020.104029
[8]
Conway, D., & Schipper, E. L. F. (2011). Adaptation to Climate Change in Africa: Challenges and Opportunities Identified from Ethiopia. Global Environmental Change, 21, 227-237. https://doi.org/10.1016/j.gloenvcha.2010.07.013
[9]
Cooper, P. J. M., Dimes, J., Rao, K. P. C., Shapiro, B., Shiferaw, B., & Twomlow, S. (2008). Coping Better with Current Climatic Variability in the Rain-Fed Farming Systems of Sub-Saharan Africa: An Essential First Step in Adapting to Future Climate Change? Agriculture, Ecosystems & Environment, 126, 24-35. https://doi.org/10.1016/j.agee.2008.01.007
[10]
Di Baldassarre, G., Montanari, A., Lins, H., Koutsoyiannis, D., Brandimarte, L., & Blöschl, G. (2010). Flood Fatalities in Africa: From Diagnosis to Mitigation. Geophysical Research Letters, 37, L22402. https://doi.org/10.1029/2010gl045467
[11]
Donque, G. (1972). The Climatology of Madagascar. In MonographiaeBiologicae (pp. 87-144). Springer. https://doi.org/10.1007/978-94-015-7159-3_3
[12]
Field, C. B., Barros, V. R., David, J. D., Mach, K. J. et al. (2014). Climate Change 2014: Impacts, Adaptation, and Vulnerability: Part A: Global and Sectoral Aspects. https://www.cambridge.org/9781107641655
[13]
Funk, C., Pedreros, D., Nicholson, S., Hoell, A., Korecha, D., Galu, G. et al. (2019). Examining the Potential Contributions of Extreme “Western V” Sea Surface Temperatures to the 2017 March-June East African Drought. Bulletin of the American Meteorological Society, 100, S55-S60. https://doi.org/10.1175/bams-d-18-0108.1
[14]
Haile, G. G., Tang, Q., Hosseini-Moghari, S., Liu, X., Gebremicael, T. G., Leng, G. et al. (2020). Projected Impacts of Climate Change on Drought Patterns over East Africa. Earth’s Future, 8, e2020EF001502. https://doi.org/10.1029/2020ef001502
[15]
Hastenrath, S. (2001). Variations of East African Climate during the Past Two Centuries. Climatic Change, 50, 209-217. https://doi.org/10.1023/a:1010678111442
[16]
Ingeri, C., Wen, W., Sebaziga, J. N., Iyakaremye, V., Ekwacu, S., Ayabagabo, P. et al. (2024). Potential Driving Systems Associated with Extreme Rainfall across East Africa during October to December (OND) Season 2019. Journal of Geoscience and Environment Protection, 12, 25-49. https://doi.org/10.4236/gep.2024.127003
[17]
IPCC (2021). Summary for Policymakers. Climate Change 2021: The Physical Science Basis. Intergovernmental Panel on Climate Change (IPCC).
[18]
Jury, M. R. (2013). Climate Trends in Southern Africa (with Erratum). South African Journal of Science, 109, 1-11. https://doi.org/10.1590/sajs.2013/980
[19]
Kebacho, L. L., Ongoma, V., & Chen, H. (2024). Influence of ENSO, Southern Annular Mode, and IOD on the Interdecadal Change of the East Africa ‘Short Rains’. Climate Dynamics, 62, 4315-4329. https://doi.org/10.1007/s00382-024-07136-y
[20]
Kijazi, A. L., & Reason, C. J. C. (2009). Analysis of the 2006 Floods over Northern Tanzania. International Journal of Climatology, 29, 955-970. https://doi.org/10.1002/joc.1846
[21]
Lawrence, D., & Vandecar, K. (2015). Effects of Tropical Deforestation on Climate and Agriculture. Nature Climate Change, 5, 27-36. https://doi.org/10.1038/nclimate2430
[22]
Liebmann, B., Hoerling, M. P., Funk, C., Bladé, I., Dole, R. M., Allured, D. et al. (2014). Understanding Recent Eastern Horn of Africa Rainfall Variability and Change. Journal of Climate, 27, 8630-8645. https://doi.org/10.1175/jcli-d-13-00714.1
[23]
Mafie, G. K. (2022). The Impact of Climate Change on Agricultural Productivity in Tanzania. International Economic Journal, 36, 129-145. https://doi.org/10.1080/10168737.2021.2010229
[24]
Mokria, M., Gebrekirstos, A., Abiyu, A., Van Noordwijk, M., & Bräuning, A. (2017). Multi-Century Tree-Ring Precipitation Record Reveals Increasing Frequency of Extreme Dry Events in the Upper Blue Nile River Catchment. Global Change Biology, 23, 5436-5454. https://doi.org/10.1111/gcb.13809
[25]
Morton, J. F. (2007). The Impact of Climate Change on Smallholder and Subsistence Agriculture. Proceedings of the National Academy of Sciences, 104, 19680-19685. https://doi.org/10.1073/pnas.0701855104
[26]
Msofe, N. K., Sheng, L., Li, Z., & Lyimo, J. (2020). Impact of Land Use/Cover Change on Ecosystem Service Values in the Kilombero Valley Floodplain, Southeastern Tanzania. Forests, 11, Article 109. https://doi.org/10.3390/f11010109
[27]
Müller, C., Cramer, W., Hare, W. L., & Lotze-Campen, H. (2011). Climate Change Risks for African Agriculture. Proceedings of the National Academy of Sciences, 108, 4313-4315. https://doi.org/10.1073/pnas.1015078108
[28]
Niang, I., Ruppel, O. C., Abdrabo, M. A. et al. (2014). Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working Group to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press.
[29]
Nicholson, S. E. (2017). Climate and Climatic Variability of Rainfall over Eastern Africa. Reviews of Geophysics, 55, 590-635. https://doi.org/10.1002/2016rg000544
[30]
O’Reilly, C. M., Alin, S. R., Plisnier, P., Cohen, A. S., & McKee, B. A. (2003). Climate Change Decreases Aquatic Ecosystem Productivity of Lake Tanganyika, Africa. Nature, 424, 766-768. https://doi.org/10.1038/nature01833
[31]
Osima, S., Indasi, V. S., Zaroug, M., Endris, H. S., Gudoshava, M., Misiani, H. O. et al. (2018). Projected Climate over the Greater Horn of Africa under 1.5˚C and 2˚C Global Warming. Environmental Research Letters, 13, Article 065004. https://doi.org/10.1088/1748-9326/aaba1b
[32]
Otieno, V. O., & Anyah, R. O. (2013). CMIP5 Simulated Climate Conditions of the Greater Horn of Africa (GHA). Part 1: Contemporary Climate. Climate Dynamics, 41, 2081-2097. https://doi.org/10.1007/s00382-012-1549-z
[33]
Pascale, S., Lucarini, V., Feng, X., Porporato, A., & ul Hasson, S. (2016). Projected Changes of Rainfall Seasonality and Dry Spells in a High Greenhouse Gas Emissions Scenario. Climate Dynamics, 46, 1331-1350. https://doi.org/10.1007/s00382-015-2648-4
[34]
Pereira, L. (2017). Climate Change Impacts on Agriculture across Africa. In Oxford Research Encyclopedia of Environmental Science. Oxford University Press. https://doi.org/10.1093/acrefore/9780199389414.013.292
[35]
Plumptre, A. J., Davenport, T. R. B., Behangana, M., Kityo, R., Eilu, G., Ssegawa, P. et al. (2007). The Biodiversity of the Albertine Rift. Biological Conservation, 134, 178-194. https://doi.org/10.1016/j.biocon.2006.08.021
[36]
Reason, C. J. C., & Keibel, A. (2004). Tropical Cyclone Eline and Its Unusual Penetration and Impacts over the Southern African Mainland. Weather and Forecasting, 19, 789-805. https://doi.org/10.1175/1520-0434(2004)019<0789:tceaiu>2.0.co;2
[37]
Rowhani, P., Lobell, D. B., Linderman, M., & Ramankutty, N. (2011). Climate Variability and Crop Production in Tanzania. Agricultural and Forest Meteorology, 151, 449-460. https://doi.org/10.1016/j.agrformet.2010.12.002
[38]
Schlenker, W., & Lobell, D. B. (2010). Robust Negative Impacts of Climate Change on African Agriculture. Environmental Research Letters, 5, Article 014010. https://doi.org/10.1088/1748-9326/5/1/014010
[39]
Schott, F. A., Xie, S., & McCreary, J. P. (2009). Indian Ocean Circulation and Climate Variability. Reviews of Geophysics, 47, RG1002. https://doi.org/10.1029/2007rg000245
[40]
Sebaziga, J. N., Safari, B., Ngaina, J. N., & Ntwali, D. (2024). Spatial Variability of Seasonal Rainfall Onset, Cessation, Length and Rainy Days in Rwanda. Theoretical and Applied Climatology, 155, 7591-7608. https://doi.org/10.1007/s00704-024-05086-3
[41]
Shongwe, M. E., van Oldenborgh, G. J., van den Hurk, B., & van Aalst, M. (2011). Projected Changes in Mean and Extreme Precipitation in Africa under Global Warming. Part II: East Africa. Journal of Climate, 24, 3718-3733. https://doi.org/10.1175/2010jcli2883.1
[42]
Song, Y., Semazzi, F. H. M., Xie, L., & Ogallo, L. J. (2004). A Coupled Regional Climate Model for the Lake Victoria Basin of East Africa. International Journal of Climatology, 24, 57-75. https://doi.org/10.1002/joc.983
[43]
Taylor, C. M., Belušić, D., Guichard, F., Parker, D. J., Vischel, T., Bock, O. et al. (2017). Frequency of Extreme Sahelian Storms Tripled since 1982 in Satellite Observations. Nature, 544, 475-478. https://doi.org/10.1038/nature22069
[44]
Teshome, A., & Zhang, J. (2019). Increase of Extreme Drought over Ethiopia under Climate Warming. Advances in Meteorology, 2019, 1-18. https://doi.org/10.1155/2019/5235429
[45]
Trenberth, K. (2011). Changes in Precipitation with Climate Change. Climate Research, 47, 123-138. https://doi.org/10.3354/cr00953
[46]
Vande Weghe, J. P. (2004). Forests of Central Africa: Nature and Man. Protea Boekhuis.
[47]
Verburga, P., & Hecky, R. E. (2009). The Physics of the Warming of Lake Tanganyika by Climate Change. Limnology and Oceanography, 54, 2418-2430. https://doi.org/10.4319/lo.2009.54.6_part_2.2418
[48]
Washington, R., James, R., Pearce, H., Pokam, W. M., & Moufouma-Okia, W. (2013). Congo Basin Rainfall Climatology: Can We Believe the Climate Models? Philosophical Transactions of the Royal Society B: Biological Sciences, 368, Article 20120296. https://doi.org/10.1098/rstb.2012.0296
[49]
Werth, D., & Avissar, R. (2002). The Local and Global Effects of Amazon Deforestation. Journal of Geophysical Research: Atmospheres, 107, LBA 55-1-LBA 55-8. https://doi.org/10.1029/2001jd000717
[50]
Williams, A. P., & Funk, C. (2011). A Westward Extension of the Warm Pool Leads to a Westward Extension of the Walker Circulation, Drying Eastern Africa. Climate Dynamics, 37, 2417-2435. https://doi.org/10.1007/s00382-010-0984-y
