An Assessment of Rainfall Distribution Pattern and Climate Extremes in Southern Nigeria
- March 19, 2018
- Posted by: RSIS
- Categories: Environmental Science, Social Science
International Journal of Research and Innovation in Social Science (IJRISS) | Volume II, Issue III, March 2018 | ISSN 2454-6186
An Assessment of Rainfall Distribution Pattern and Climate Extremes in Southern Nigeria
Ibeabuchi U, Egbu, A. U and Kalu, A. O.
Corresponding e-mail: domegacometh@yahoo.com; Phone: +234(0)8065345364; 9021728394o
Abstract: – Choosing a probability distribution to represent the precipitation depth at various durations has long been a topic of interest in climatology and hydrology. The annual rainfall data for 38 years (between 1972 and 2013) were collected from the Nigerian meteorological stations Agency (NIMET) for nine weather stations southern Nigeria. The data were then processed to identify the maximum and minimum rainfall received a day (24hrs duration). The mean, mode, median, skewedness and standard deviation for the study period was derived. The average nearest neighbor analysis was performed to study the distribution of weather stations and rainfall, the results revealed a dispersed (1.88) distribution and the rainfall is well distributed in the study area. The annual mean daily rainfall received was 2.24mm/day for Abeokuta, 1.36mm/day for Calabar and Enugu, 2.03 mm/day for Ikeja, 1.32 mm/day for Port Harcourt, 0.04 mm/day for Benin, and 0.01 mm/day for Ibadan. The median of 0.69mm/day was record for Abeokuta, 0.43mm/day for Calabar and Enugu, 0.59 mm/day for Ikeja, and 0.43 mm/day for Port Harcourt, while the mode of 0.01mm/day was record for Abeokuta, 0.04mm/day for Calabar and Enugu, 0.12 mm/day for Ikeja, and 0.04 mm/day for Port Harcourt. The standard deviation of 7.12 mm/day was record for Abeokuta, 3.10mm/day for Calabar and Enugu, 4.29 mm/day for Ikeja, and 2.59 mm/day for Port Harcourt. This indicates a very large range of fluctuation during the period of study between the coastal area and inland. The rainfall data were analyzed to identify the best fit probability distribution for each period of study using the Rainfall Distribution (Bulletin 17B). The Normal distribution method was used to study climate and weather extreme. The Ordinary Least Squares (OLS) regression was used to model and predict relationships of weather station in term of rainfall return period or occurrences, trend and location. The scientific results clearly established that the analytical procedure devised and tested in this study is suitably applied for the identification of the best fit probability distribution of weather parameters. Also, the study has presented facts on climate extremes for present and future study.
Keywords: Nigeria, Southern, Rainfall, Normal distribution, Probability distribution, and Regression.
