Implications of Trends and Cycles of Rainfall on Agriculture and Water Resource in the Tropical Climate of Nigeria

A. A. Alli, P. G. Oguntunde, A. A. Olufayo, J. T. Fasinmirin

Abstract


Trends and cycles of rainfall over Nigeria, as well as their implications for water resources and agriculture, have been studied since 1960 on annual, seasonal and monthly bases. Rainfall data of 47 years (1960 – 2006) were obtained for twenty stations over Nigeria for the evaluation of trends using the Mann-Kendall test. Auto correlation spectral analysis was also used to detect cycles of rainfall. The result showed dominant peaks in rainfall return at various rates. For instance, Akure, Benin, Calabar, Maiduguri and Yola stations had decreasing trends of annual rainfall at rates of 1.084, 0.03, 1.80, 0.75, and 0.12 mm/month/yr, respectively with return periods between 1-2 years and 7-10 years. Rainfall trends increased in about 75 % of the locations with return period of dominant peaks varying between 1-2 years and 15 years. Abuja recorded the highest peak of rainfall in the month of October at the rate of 4.7 mm/month/yr with return period of 1-2 years. These results indicate different spatial effects on ecosystem and agriculture. Some of the implications of these trends on agriculture and water resources vary from one station to another, depending on the trends and magnitude of return period of rainfalls. Bauchi and Minna cities are expected to experience serious desertification and complete depletion of underground water due to the effects of no change in trend of rainfall. Meanwhile, agricultural activities are expected to thrive in places like Ibadan, Gusua, Osogbo and others that have moderate increase in trends of rainfall and temperature.


Keywords


Rainfall, Trends, Cycles, Mann-Kendall and Auto correlation spectral analysis

Full Text:

PDF

References


Anuforom, A.C, and Okpara, J.N, 2004: The Influence of Climate Variability and Climate Change on Agricultural production in Nigeria, Directorate of applied meteorological services, Nigeria Meteorological Agency, Abuja

Crowley, T.J., 2000.Causes of Climate Change over the last 1000 years. Science (in press)

Duce, P., Spano, D., Motroni, A., Canu, S., 2003. Rishchio climatico per lagricoltura in ambiente mediterraneo.Proc. Workshop CLIMAGR, 16-17 January 2003, Cagilari, Italy, Pp 39-46. IITA Report 1992:

IPCC, 1995. Climate change 1995. The science of climate change. The second IPCC assessment report. Cambridge University Press, Cambridge, UK, pp. 572.

IPCC, 2007: Climate Change and Agriculture in Africa: Impact Assessment and Adaptation Strategies. www.earthprint.com.

Kendall, M.G., Stuart, A (1961). The advanced theory of statistics 2. London Charles Griffen Pp 483-484.

Naidu, C.V and Subbaramaya, I., 1992. Spatial variation and trends in the Indian monsoon rainfall. Intl. J. Clim., 12: 597-609.

Odekunle, T.O., 2004. Rainfall and Nigerian Growing Season. Intl. J. Climatol. 24: 467-479.

Oguntoyinbo, J.S and Odingo, R.S. 1997. Climate Variability and Land Use. In proceedings of the World Climate Conference. WMO Publication No. 537. World Meteorological Organization Geneva, 552-580.

Oguntunde, P.G,, Friese, J.N., Van de Giesen and H.H.G. Savenije., 2006. Hydroclimatology of the Volta River Basin in West Africa; Trends and Variability 1901-2002. Journal of physics and Chemistry of the Earth doi;10.1016/ J.PCE.2006.02.062. sustainable agriculture. Agric. for meteorol. 103, 11-26.

Smith. M., 2000. Application of climatic data for planning and management of sustainable rain-fed and irrigated crop production. Journal of Agricultural and Meteorology paper 103, Rome, Pp 108.

Tosic, I., 2005. Analysis of precipitation series for Belgade. Theor Appl Climatol 77, 128-135

UNDP, 2004. Reducing disaster risk; a challenge for development. In: pelling M. (Eds), UNDP Global Report, UNDP, 146 Pp.


Refbacks

  • There are currently no refbacks.