American Journal of Geophysics, Geochemistry and Geosystems
Articles Information
American Journal of Geophysics, Geochemistry and Geosystems, Vol.6, No.3, Sep. 2020, Pub. Date: Aug. 8, 2020
Historical Trends in Extreme Precipitation Events, Their Relationship and Potential Implication on the Environment in Sub-Saharan Africa
Pages: 82-90 Views: 143 Downloads: 50
[01] Kenny Nyirenda, Department of Geology and Survey, Copperbelt University, Kitwe, Zambia.
[02] Makaiko Nyirenda, Department of Geology and Survey, Copperbelt University, Kitwe, Zambia.
Understanding trends in extreme rainfall events is important in mitigating their impacts on socioeconomic sectors such as health, agriculture, water resources and the environment. In this study, historical trends in total annual precipitation and number of days with heavy precipitation events, their relationships and potential implications on the environment in Sub Sahara Africa were investigated. Gridded daily precipitation data from National Oceanic Atmosphere Administration (NOAA) with the spatial coverage of 0.50 - degree latitude x 0.50 - degree longitude grid (720x360) and temporal coverage from 1979 to 2018 were used. Mannkendall test was used to generate trends in days with heavy precipitation events (d95P) and total annual precipitation (prcptot) at 5% significance level. Trends in d95P and prcptot were then assessed and correlated to determine their relationships and potential impact on the environment. Results of the study indicate statistically significant decreasing trends in prcptot over Central Africa, the southern part of West Africa and in some parts of Southern Africa. Some pockets of significant increasing trends in prcptot were observed around Southern Africa, some parts of East Africa and the northern parts of West Africa. The largest portion of sub-Sahara Africa shows non significant trends in prcptot. Variable trends observed in prcptot could be attributed to regional differences in climate. In terms of d95P, significant decreasing trends are observed in Central Africa, South Central Africa and the southern parts of West Africa. Significant increasing trends in d95P events were observed in some parts of East Africa and some northern parts of West Africa. However, the magnitudes of these trends in terms of the Sen’s slope are minimal. Like prcptot, the largest parts of sub-Saharan Africa shows non significant trend in d95P. Trends in d95P and prcptot show a positive correlation. This indicates that the increase in d95P contributes greatly to the increase in prcptot over the base period. Regions which showed positive correlation between significant increasing trends in prcptot and d95P may be prone to flooding, landslides and related disasters. It should however be noted that most parts of sub-Saharan Africa indicate non significant trends in both prcptot and d95P at 5% significant level.
Precipitation, Extreme Events, Africa
[01] Donat, M. G., Alexander, L. V., Yang, H., Durre, I., Vose, R., Dunn, R. J. H.,... & Hewitson, B. (2013). Updated analyses of temperature and precipitation extreme indices since the beginning of the twentieth century: The HadEX2 dataset. Journal of Geophysical Research: Atmospheres, 118 (5), 2098-2118.
[02] United Nationa-Water (2008). Transboundary waters: sharing benefits, sharing responsibilities. Thematic Paper, 20.
[03] Intergovernmental Panel on Climate Change, IPPC.(2007). Climate Change Impacts, Adaptation and Vulnerability, Summary for Policy-makers. A Report of the working group II of the IPCC, Fourth Assessment report.
[04] Allan, R. P., & Soden, B. J. (2008). Atmospheric warming and the amplification of precipitation extremes. Science, 321, 1481–1484.
[05] Boko, M., Nlang, I., Nyong, A., Vogel, C., Githeko, A., Medany, M.,... Yanda, P. (2007). Africa. In M. L. Parry, O. F. Canziani, J. P. Palutikof, P. J. Van der Linden, & C. E. Hanson (Eds.), Climate change 2007: Impacts, adaptation and vulnerability. Contribution of working group II to the 4th assessment report on the Intergovernmental Panel on Climate Change (pp. 433–467). Cambridge: Cambridge University Press.
[06] Easterling, D. R., and Coauthors, 1997: Maximum and minimum temperature trends for the globe. Science, 277, 364–367.
[07] New, M., et al. (2006), Evidence of trends in daily climate extremes over southern and west Africa, J. Geophys. Res., 111, D14102, doi: 10.1029/2005JD006289.
[08] Pohlert, T. (2018). Non-parametric trend tests and change point detection.
[09] Lebel, T., & Ali, A. (2009). Recent trends in the Central and Western Sahel rainfall regime (1990–2007). Journal of Hydrology, 375 (1-2), 52-64.
[10] Nka, B. N., Oudin, L., Karambiri, H., Paturel, J. E., Ribstein, P. (2015). Trends in floods in West Africa: analysis based on 11 catchments in the region. Hydrology and Earth System Sciences, 19 (11), 4707-4719.
[11] Hountondji, Y., De Longueville, F., & Ozer, P. (2011, August). Trends in extreme rainfall events in Benin (West Africa), 1960-2000. In Proceedings of the 1st International Conference on Energy, Environment and Climate Change.
[12] Usman, M. T., & Reason, C. J. C. (2004). Dry spell frequencies and their variability over southern Africa. Climate research, 26 (3), 199-211.
[13] Kruger A. C., Nxumalo M. P (2017). Historical rainfall trends in South Africa: 1921–2015.
[14] Dezfuli, A. (2017). Climate of western and central equatorial Africa.
[15] Phiri, J. S., Moonga, E., Mwangase, O., Chipeta, G. (2013). Adaptation of Zambia agriculture to climate change–A Comprehensive review of the utilisation of the agro-ecological Regions. A Review for the Policy Makers. Zambia Academy of Sciences (ZaAS).
[16] World Bank (2009). Zambia Managing Water for Sustainable Growth and Poverty Reduction.
[17] Bwalya S. M. (2010). Climate Change in Zambia: Opportunities for Adaptation and Mitigation through Africa Bio-Carbon Initiative.
[18] Kanyanga, K. (2008). Precipitation and Temperature variations in Zambia: Evidence of climate change. A paper presented at Media Workshop on Climate Change and Global Warming held in Chipata, Zambia.
[19] Francis Tapon (2020). Defining sub sahara (source:
[20] Omondi, P. A. O., Awange, J. L., Forootan, E., Ogallo, L. A., Barakiza, R., Girmaw, G. B.,... & Kilavi, M. (2014). Changes in temperature and precipitation extremes over the Greater Horn of Africa region from 1961 to 2010. International Journal of Climatology.
[21] Hastenrath S, Polzin D, Mutai C. 2010. Diagnosing the droughts and floods in equatorial East Africa during boreal autumn 2005–08. Journal of Climate 23: 813–817.
[22] Viste E, Korecha D, Sorteberg A. 2012. Recent drought and precipitation tendencies in Ethiopia. Theoretical and Applied Climatology 112 (3–4): 535–551.
[23] Nyirenda, K., & Sachikumba, E. (2019). Trend Analysis of Extreme Rainfall in Zambia and Its Potential Implication on Water Resources Availability and Agricultural Productivity. change, 3, 17.
[24] Omondi P, Awange JL, Ogallo LA, Okoola RA, Forootan E. 2012a. Decadal rainfall variability modes in observed rainfall records over East Africa and their relations to historical sea surface temperature changes. Journal of Hydrology 464–465: 140–156.
[25] NASAC (2015) Climate change adaptation and resilience in Africa. Recommendations to policymakers. Network of African Science Academies.
[26] United Nations (2017). World population (Source:
[27] World Bank (2015b) Regional dashboard: poverty and equity, Sub-Saharan Africa. region/SSA.
[28] World Bank (2013) Fact sheet: The World Bank and agriculture in Africa. (Accessed 20th March, 2019).
[29] World Bank (2015a). Rainfed agriculture. Accessed on 20th March, 2019.
[30] World Meteological Organization (2014). The Climate in Africa.
[31] Center for Energy and Climate Solutions (2020). Extreme Precipitation and Climate Change (source:
MA 02210, USA
AIS is an academia-oriented and non-commercial institute aiming at providing users with a way to quickly and easily get the academic and scientific information.
Copyright © 2014 - American Institute of Science except certain content provided by third parties.