Abstract

Rainfall variation is a major impact of climate change. Understanding its patterns and trends is essential for developing effective adaptation measures to minimize its impacts on flooding. This study was carried out is to access the variations in rainfall in Benin City, Nigeria and its implications on flooding. The rainfall and temperature data obtained from the Nigeria meteorological agency were analysed using a trend analysis. The temperature in the study area showed an increasing trend but fluctuated across the years with 1991 as the least with 26.8°C, and 2015 as the highest with 28.5°C. The rainfall in the study area showed a seemingly overall horizontally steady trend. It revealed a fluctuating pattern with a sharp and massive decline in 2015 making it the year with the least amount of rainfall (1159.5mm)). It showed an abrupt ascension in 2016 and further increased in 2017. 2019 and 2021 tend to have the highest amount of rainfall of 3107.2mm and 3085.2mm respectively. The evaluation of the rainfall variation showed 17 years of excess rainfall and 15 years deficit relative to the mean (2284.5mm). The pattern of rainfall observed in the study area could be attributed to climate variability/change. According to the slope map of the study area obtained using techniques of Geographic Information System, the southern area which have a lower slope value of 0 – 89,170 is more vulnerable to flooding. It can be deduced from the result that Benin city located in the southern part of Edo state in relation to other part of the state is more vulnerable to flooding. As such effort should be made to mitigate climate change and flood disaster.

Key Words: Rainfall variation, Climate variability, Vulnerable, Slope, Flooding, Benin city