A Contribution of GIS Methods to Assess the Aquifer Vulnerability to Contamination: A Case Study of the Calcareous Dorsal (Northern Rif, Morocco)

Abstract

Karst groundwater constitutes the main resource for drinking water supply in Chefchaouen region, North Morocco. However, the karstic aquifers are highly vulnerable to the pollution because of the deforestation which favors the soil erosion and the landslides. Therefore, the groundwater is loaded with suspended sediment. The fertilizers disseminated for agriculture can also infiltrate and concentrate in the saturated zone of the aquifer. In this study, the geographic information system (GIS) provides an effective tool for groundwater contamination risk assessment, because it facilitates multicriteria analysis and updates the models developed. The EPIK model based on GIS uses four environmental parameters (Epikarst, Protective cover, Infiltration condition and Karst network development) to evaluate the intrinsic vulnerability of groundwater contamination po-tential. Each of these parameters is presented as a thematic map. After adding all data, the final result provides vulnerability map according to the protection factor relation based on which the protection zones' map is created.