Cotonou Megacity of Benin Facing Climate Change: Risk of Flooding

Abstract

This study assessed the current and future influence of rainfall trends on flooding phenomena in Cotonou. For this purpose, climate data (1989 to 2023) were collected from the National Agence of Meteorology and simulation data (2024 to 2100) from the Regional Climate Models site. Analysing climate projections on the national scale requires high-resolution data following the RCP 4.5 model. The data were processed using Excel 2016. It consisted of analysing the evolution of rainfall in Cotonou (1989 to 2023) and describing climate projections from 2024 to 2100. The results of the climate series analysis reveal a change in the climatic regime. Seasonal rainfall has increased over the years. Rainfall simulation data showed an average increase of 100 mm in rainfall from 2024 to 2100. The literature review showed that the risk of flooding in Cotonou is also intrinsically linked to location, land use, drainage structures, relief and solid and liquid waste collection.