Impact of climate change on the Oueme basin in Benin

Abstract

The world is currently facing disruption of the climate system related to global warming. Climate is a crucial factor in ecosystem assessment. Benin is considered a vulnerable area, particularly its south, which is a coastal zone. The current study evaluated the impact of climate on ecosystems in the Oueme basin. An understanding of indicator difference between 2000 and 2016 was provided. Afterwards, systems to calculate the sensitivity index (S) to accurately identify the extremely sensitive area within the basin were designed for 2016. Indeed, detecting sensitive areas is a suitable vehicle to promote sustainability. Then, using ten indicators, mainly obtained from satellite images, grouped into three factors (climate, land use, and warming), and based on multicriteria methods, specifically the analytic hierarchy process (AHP) and principal component analysis (PCA), the index S was performed. Results revealed decreases in normalized difference water index (NDWI) and normalized difference vegetation index (NDVI) and increases in land surface temperature (LST), normalized difference building index (NDBI), and potential evapotranspiration (PET). According to the AHP system, percentages of 39%, 46%, and 15% were determined to be the lowly, moderately, and extremely sensitive areas. In comparison, the PCA system identified ratios of 44%, 41%, and 15% as, respectively, the lowly, moderately, and extremely sensitive areas. Spatially and regardless of the established systems, the southern Oueme basin (Littoral, Atlantique, and Oueme) was consistently identified as extremely sensitive. In contrast, the northern Oueme basin (Donga and Borgou) was stable. Referring to Pearson's correlation, climate (extremely) and land use (moderately) were highlighted to be considered threats to ecosystems in the Oueme basin.

Keywords

• Ecosystem assessment
• Indicator difference, sensitivity index (S), multicriteria methods
• southern Oueme basin, climate