Impact of Urbanization on the Tile Watershed in the Urban Commune of N’Zerekore

Rivers still play an important role in our societies, mainly as a water resource and a place of recreation, but nowadays, human activities have led to a profound modification of the natural environment, particularly in the urban environment. The Tile River has been transformed nowadays as a channel for evacuating and draining waste from the city of N’Zerekore. The objective of this study is to analyze the effects of urbanization on the watershed of the Tile River in the urban commune of N’Zerekore, this area which is experiencing enormous pollution problems linked to uncontrolled urban sprawl. To assess the dynamics of the spatial-temporal occupation of urbanized areas, Landsat satellite image processing was used. Its aim was to produce a map of urbanized areas over three (30) years from 1993 to 2023 in order to compare them to understand the changes induced over time. The methodology for analyzing the quality of surface water in Tile consisted of identifying water sample collection sites, waste dumps, mechanical and brick workshops, markets and habitats around the watercourse. A survey of the local population and an analysis of the physicochemical and bacteriological parameters collected were carried out. The results obtained from the processing of Landsat satellite images showed that the increase in urban areas over the past thirty years has caused disturbances that have led to changes in the quality of surface water in N’Zerekore. Physicochemical and bacteriological analyses of samples from three (3) sampling sites were carried out. The results of the analysis of these water samples show a deterioration in the physicochemical and bacteriological quality of its water according to the 2011 WHO standards, particularly for surface water. These results highlighted potential pollution of the water in Tile due to the socio-economic activities of local residents and especially because of the proximity of homes to the riverbed.