SPATIO-TEMPORAL VARIATION IN RAINFALL OVER SOUTH-WESTERN NIGERIA

Ozabor .F and Obisesan .A

Department of Geography and Environmental Management

University of Port-Harcourt,Port-Harcourt

E-mail: Famphidoz@gmail.com

ABSTRACT

This study is on thespatio-temporal variation in rainfall over south-western Nigeria. The study adopts the ex-post facto research design. Three grand stations (Oshogbo; Ibadan and Ikeja) of the five in the region were selected for this study. Secondary annual rainfall data for two climatic normal were collected from the archive of NIMET. The Analysis of Variance (ANOVA) was adopted for the purpose of data analysis. Findings include that in the first decade (1955-1965), the rainfall amount for ikeja was 1718.25mm, Ibadan is 1375.36mm and Oshogbo is 1636.28mm. The decade 1965-1975, Ikeja recorded rainfall amount of 1745.47mm; but the amount of rainfall generated for Ibadan was more than that of Oshogbo as they both recorded 1381.61mm and 1345.41mm respectively. Furthermore, Lagos seem to have experienced dryer conditions in the decade 1985-1995 as the amount (1280.139mm) of rainfall generated for that decade was lower than that of Oshogbo (1393.42mm). In terms of anomalies, the individual stations in the study showed that while some periods are anomaly wet others are dry. However, in the display of anomalies in the observed rainfall patterns, the last decades in all the stations are anomaly wet, thereby creating a departure from the trends. However, the ANOVA model is significant at P (0.001) < 0.05. This signifies that there is a statistical significant variation in the rainfall amounts generated among weather stations in the region for the two normal of interest.