Assessment of vulnerability to pollution of aquifers of weathered layer by DRASTIC and SYNTACS methods: Case of M'Bahiakro city, Central Côte d'Ivoire

The prevention against the pollution of groundwater has been over three decades a major concern for the specialists of the field of water. To that purpose, many methods that use intrinsic parameters have been adopted since 1987. For this study, two methods have been adopted to enhance the robustness of results. It is about DRASTIC and SINTACS who use both the intrinsic features of aquifers. The errors margins have been calculated for both maps so as to appreciate their veracity rate. Finally, these maps have been superposed to translate an infiltration on the salts content map which is supped to translate an infiltration from superficial origin. The results clearly indicate that whatever the method, three classes of vulnerability have been identified: the strong vulnerability class, the average vulnerability and the low vulnerability classes. Globally, the area remains moderately vulnerable. Whatever the errors margin that was determined shows the respective values: 16,74 % and 18,04 % for the DRASTIC and SINTACS methods. The superposition of the salts content map shows that the pollutant found in groundwater might have an origin that might not be from a superficial origin infiltration. The use of statistical tests as contribution to this study could lead to determine the origins of these pollutants.