The poor condition of Grand-Bassam’s boreholes and the drinking water wells of the local population led to an assessment of their hygienic quality. Several data analysis approaches were performed on 4 boreholes and 17 well water samples. Indeed, physico-chemical and bacteriological analysis, as well as Water Quality Index and Principal Component Analysis were used to differentiate the characteristics of borehole and well water in order to determine the level and origin of water pollution. The results showed that all chemical borehole water quality was poor, while of 35% and 65% of well chemical water quality were good and satisfactory, respectively. Owns to soil nature, the iron and manganese contents were 0.73 ± 0.23 mg.L-1 and 0.1 ± 0.07 mg.L-1, respectively. The high presence of fecal streptococci, salmonella and shigella in the borehole water, as well as Escherichia coli, total coliforms and fecal coliforms in the well water, thereby underscoring the poor microbiological quality of water (90,53% of borehole and 92% of well), which is contaminated by septic tank water. Furthermore, the high presence of Salmonella in borehole water suggests that it may contain hydrogen sulfide, which is responsible for its unpleasant odors.

The Aghien lagoon watershed is located in peripheral north-east areas of Abidjan. This space is accelerated population growth more than more important. The rate of urbanization is higher than 60% in 2014 (RGPH, 2014). Also, does the acceleration of urbanization result in vegetation cover degradation for the benefit of the built environment and a peri-urban agriculture. Also, does the acceleration of urbanization result in vegetation cover degradation for the benefit of the built environment and a peri-urban agriculture. This study aims to analyze in part one the diachronic evolution of vegetation cover between 1987-2000 and 2000-2015, and second part its takes stock of this dynamic between 1987 and 2015. Thus, the analysis of land use dynamics in the Aghien basin is based on the the vegetation mapping of landsat images. The methodology is based on the supervised classification by maximum likelihood of landsat images The results of the dynamics of land use in the basin in 1987, 2000 and 2015 indicate a decline in forest cover and perennial crops in favor of built environment and bare soil (+10.98%), subsistence crops and fallow (+11.37) over the period (1987-2015). Urbanization and increase crops are caused modifications of vegetation cover in outskirt of basin. These changes are mainly due to demographic pressure and unsustainable agricultural practics.