Abstract
Rainfall in Nigeria is subjected to wide variability both in time and space. This variability has assumed a more pronounced dimension as a result of climate change. In this paper, cluster analyses were used to study rainfall variability in Nigeria. Rainfall data in 20 locations spread across the geopolitical and ecological zones of Nigeria were subjected to hierarchical cluster analysis and analysis of time series and coefficient of variation for over periods spanning 30 years. Maps of spatial variations of mean annual rainfall and mean rainfall coefficient of variation were produced using ARCGIS 10.1. Furthermore, a better understanding of temporal variation of rainfall was sought by an investigation into the time series of rainfall coefficients of variation. It was found that the southern parts of the country were given to more severe rainfall variability/fluctuations than the northern parts. The north central parts exhibited more similarity to the southern parts than the other northern locations. The relationship between average annual rainfall and the coefficient of rainfall variation was found to follow a power law with R 2 value approximately 0.7. With respect to variability of annual rainfall, three zones emerged as follows: a linear relationship (R 2 = 0.90) exists between coefficient of variation and average annual rainfall for the rainforest zone of the southsouth; a power law (R 2 = 0.86) exists between coefficient of variation and average annual rainfall for all rainforest and derived guinea savannah zones of the southeastern and southwestern states; and a logarithmic relationship (R 2 = 0.54) exists between coefficient of variation and average annual rainfall for all northern states regardless of ecological zone. Generally, in-year rainfall variability increases from the northwest to the southwest; while between-year (yearly) rainfall variability increases from the north central to the southeast. This study further confirms that rainfall variability over time follows a spatial trend within a certain arbitrary boundary.
Similar content being viewed by others
References
Adefalolu DO (2007) Climate change and economic sustainability in Nigeria. Paper presented at the International conference on climate change and economic sustainability held at Nnamdi Azikiwe University, Awka, Nigeria. 12–14
Adger WN, Hug S, Brown K, Conway D, Hulme M (2003) Adaptation to climate change in the developing world. Proc Dev Stud 3(3):179–195
Akinro AO, Apeyemi DO, Ologunagba IB (2008) Climate change and environmental degradation in the Niger Delta Region of Nigeria: Its vulnerability, impacts and possible mitigations. Res J Appl Sci 3(3):167–173
Akinsanola AA, Ogunjobi KO (2014) Analysis of Rainfall and Temperature Variability Over Nigeria. Glob J Hum-Soc Sci: B 14(3): 11–7
Ayoade JO (2003) Climate Change. Vantage Publishers, Ibadan
Bunting AH, Dennet MD, Eliston J, Milford JR (1976) Rainfall trends in the West African Sahel. QJR Meteorol Soc 101:193–202
EIA (2003) Energy information administration of the US, retrieved from http://www.eia.doe.gov/emeu/cabs/nigenv.html
Federal Ministry of Environment (2003) National Communication on Climate Change. Federal Ministry of Environment, Final Draft
Folland CK, Palmer TN, Parker DE (1986) Sahel rainfall and worldwide sea temperatures 1901–85 observational modeling and simulation studies. Nature 320:602–607
Frich P, Alexander LV, Della-Marta P, Gleason B, Haylock M, Klein Tank AMG, Peterson T (2002) Observed coherent changes in climatic extremes during the second half of twentieth century. Clim Res 19:193–212
Houghton JT, Meira Filho LG, Callader BA, Harris N, Kattenberg A, Maskell K (1996) Climate changes: the science of climate change. Cambridge Press, Cambridge, p 572
Isikwue SC (2013) Analysis of rainfall variability over some cities in Nigeria using harmonic analysis technique. Niger J Phys 24:16–24
Nnaji CC (2011) Time series analysis of monthly rainfall in Nigeria with emphasis on self-organized criticality. J Sci Technol 31(1):139–151
Nnaji CC, Mama CN (2014) Preliminary assessment of rainwater harvesting in Nigeria: Focus on domestic water supply and flood mitigation. Water Resour Manag 28(7):1907–1920
Novotny EV, Sfefan HG (2007) Stream flow in Minnesota: Indicator of climate change. J Hydro 334:319–333
Obot NI, Onyeukwu NO (2010) Trend of rainfall in Abeokuta, Ogun State, Nigeria: a 2-year experience (2006–2007). J Env Iss Agric Dev Count 2(1):70–81
Obot NI, Emberga T, Ishola KS (2011) 22 years trends of annual rainfall in Abeokuta, Nigeria. Res J Appl Sci 6(4):264–271
Odekunle TO (2001) The magnitude-frequency characteristics of rainfall in Ondo, Southwestern Nigeria. Ife Res Publ Geogr 8:36–41
Odjugo PAO (2005) An analysis of rainfall pattern in Nigeria. Glob J Environ Sci 4(2):139–145
Odjugo POA (2010) General overview of climate change impacts in Nigeria. J Hum Ecol 29:47–55
Odjugo PAO, Ikhuoria AI (2003) The impact of climate change and anthropogenic factors on desertification in the semiarid region of Nigeria. Glob J Environ Sci 2(2):118–126
Ogbuene EB (2010) Environmental consequences of rainfall variability and deforestation in Southeastern Nigeria. Int J Water Soil Res 1(1–3):100–105
Oguntade PG, Abiodun BJ (2012) Analysis of trends and periodicity in long-term annual rainfall time series analysis. In: Madiwal D, Jha MK (eds) Hydrologic time series analysis: Theory and practice. Capital Publishing Company, New Delhi, pp 249–272
Olaniran OJ (2002) Rainfall anomalies in Nigeria: the contemporary understanding. Paper presented at 55th Inaugural Lecture, University of Ilorin, Nigeria, p 55
Ologunorisa EI (2004) Rainfall flood prediction in the Niger Delta, Nigeria, proceedings of international conference in hydrology: science and practice for the 21st century, London
Ragab R, Prudhomme C (2002) Climate change and water resources management in arid and semi-arid regions: Prospects and challenges for the 21st Century. Biosyst Eng 81:3–34
Ratnayake U, Herath S (2005) Changing rainfall and its impacts on landslides in Sri Lanka. J Mou Sci 2(3):218–224
UNDP/World Bank (2004) Strategic Gas Plan for Nigeria, Joint UNDP/World Bank Energy Sector Management Assistance Programme (ESMAP)
Yaya OS, Fashae OA (2014) Seasonal fractional integrated time series models for rainfall in Nigeria. Theor Appl Climatol. doi:10.1007/s00704-014-1153-8
Yaya SO, Shittu OI, Durojaye OM (2014) Time series analysis of quarterly rainfall in Southwestern Nigeria. Lambert Academic Publishing, Germany
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nnaji, C.C., Mama, C.N. & Ukpabi, O. Hierarchical analysis of rainfall variability across Nigeria. Theor Appl Climatol 123, 171–184 (2016). https://doi.org/10.1007/s00704-014-1348-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00704-014-1348-z