Ibadan Journal of the Social Sciences
Volume 22, No. 1, 2024
DOI: 10.36108/ijss/4202.22.0110
Spatial Distribution of Rainfall in Lagos Mainland, Nigeria
Adewale O. Adeyefa
Department of Geography, University of Ibadan, Nigeria
Abstract
The study examined rainfall distribution patterns for the core rainy season months of May, June, July, August, and September in a part of Lagos, Nigeria. It illustrated variations in rainfall distribution within a relatively small area of the metropolis. The datasets used in this study consisted of daily rainfall values collected using improvised rain gauges at specific locations: Otto, Makoko, Yaba, Onike, Akoka, and Bariga. Measures of central tendency were employed to determine average monthly rainfall, the average number of rainy days each month, mean daily rainfall, and average monthly rainfall per rain day (i.e., mean daily rainfall intensity). The strengths of the relationship between the average number of rainy days, mean daily rainfall intensity and average monthly rainfall were determined using correlation and regression techniques. The coefficient of variation and analysis of variance (ANOVA) were used to assess the degree of temporal variation, and test differences in the mean values of the stations, respectively. The results revealed variations in all the parameters examined across the locations. For instance, the standard deviation of rainfall in May varied from 20.83mm in Otto to 15.44mm in Bariga, whereas the corresponding values in June were 38.89mm in Otto to 36.31mm in Bariga. There was a similar variation in the number of rainy days in May, with 8 days in Otto and 10 days in Bariga. Rainy days in June varied from 11 days in Makoko to 13 days in Akoka. Although, ANOVA at = 0.05, showed no significant difference between the mean values of the various locations, even small changes in weather elements within a relatively small area could have a substantial impact on its feedback mechanisms.
Keywords: Rainfall distribution, variations, rainy days, daily rainfall intensity, Lagos.