Abstract
The pollution generated by human activities in the area “Vridi canal-Grand Bassam” puts more at risk the quaternary groundwater that supplies water to a large part of the population of the southern part of Abidjan city. This paper deals with the combined approach of geographic information systems and multicriteria analysis to delineate areas at risk of pollution of groundwater in the study area. The multicriteria analysis also incorporated the statistical and geostatistical techniques for defining the factor ratings and weightings of all the parameters under a GIS environment. The criterion for these factor ratings and weightings was the correlation coefficient of each parameter with the nitrates concentration in groundwater. Two indicators were combined for creating situations of pollution risks according to their importance: the intrinsic vulnerability indicators which combined the depth to groundwater, the net recharge, the slope, the soil media, the unsaturated hydraulic conductivity and extrinsic vulnerability characterized by the land use. The results showed that all to the site presents nitrate pollution risks with 50.7% of moderate risk, and 49.3% of high and very high risks. The areas which present the highest risks of pollution are the densely urbanized communes of Treichville, Marcory, Koumasi, Port-Bouet and Grand-Bassam. The sensitivity analysis indicates that parameters causing high sensitivity on the nitrate pollution risks map are the depth to groundwater and the recharge. The errors committed on the maps establishment are ±0.15%, ±0.40% and ±6% respectively for IV map, EV map and pollution risk map.
Highlights
Groundwater resource protection has become a critical issue worldwide
It is based on seven parameters to be determined as input for computing the DRASTIC index number, which reflects the pollution potential for the aquifer [2,3,4,5]
The objective of this study is to assess the groundwater pollution risks in area of Vridi chanel to Grand-Bassam in Abidjan city (Côte d’Ivoire) using a GIS modeling combined with a MCA and statistical procedures
Summary
Groundwater resource protection has become a critical issue worldwide. One of the approaches widely used to protect groundwater quality and reduce human health risks consists in assessing and mapping groundwater vulnerability to contamination. The term groundwater vulnerability includes two basic parameters: intrinsic vulnerability (IV) and specific vulnerability [1] The former defines the vulnerability of groundwater to contaminants generated by human activities, taking into account only the inherent hydrogeological characteristics of the area, and is independent of the nature of the contaminants. GIS provides efficient manipulation and presentation of the data and MCA provides consistent ranking of the groundwater vulnerability based upon a variety of criteria. This combination of GIS and MCA has already been used for solving the groundwater potential zone delineation problem and landfill site selection [6,7,8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
