Climate Change in Southeast Benin and Its Influences on the Spatio-Temporal Dynamic of Forests, Benin, West Africa

Abstract

The impact of anthropogenic activities on the spatiotemporal dynamics of the forest of Dogo-Kétou has been studied in relation to climate change observed in southeastern Benin. Especially, this study has detected the changes in climate parameters in southeast Benin from 1954 to 2016 and in forestland use from 1986 to 2018. A climatic break was detected, and the annual and monthly rainfall and temperature averages, the rainfall indexes, the concentration of precipitation, the number of rainy days according to the World Meteorological Organization and the bioclimatic aridity indexes were assessed. A GIS analysis was also performed based on Landsat images from 1986, 2000 and 2018 to detect the dynamic of land use and land cover of the classified forest of Dogo-Kétou. Excel 2016, Rx64 4.1.2, Rclimdex301, Khronostat1.01 and ArcGIS were used. The rainfall series showed a break in 1969. The segment from 1954 to 1968 was a period of excess rainfall with an average of 1420.46 mm/year. The segment from 1969 to 2016 was a rainfall deficit period with a reduction of 12 to 37% of rainy days and an increase of dry days for 21.4 days/year. In this last segment, southeast Benin experienced trends of its climate towards a sub-arid and arid climate. The agglomerations and bare soil of the forest of Dogo-Kétou increased to an area almost double the size between 1986 and 2018. The tree and shrub savannas gained in space from 12.1% in 2000 to 38.9% in 2018 and the dense forest and wooded savannas regressed by 52.6% in 1986 to 36.1% in 2000 then to 4.3% of the forest area in 2018. The subequatorial climate of southeastern Benin is gradually evolving towards a dry climate. The dense forest in this area is also gradually disappearing, giving way to savannas. This transformation towards the savannas was due to anthropogenic actions whose effects were strongly accentuated by climate change in this part of Benin and West Africa.