The EPIK multi-attribute method for intrinsic vulnerability assessment of karstic aquifer under semi-arid climatic conditions, case of Cheria Plateau, NE Algeria

Karst aquifers supply an important freshwater resource for MENA (Middle East and North Africa) semi-arid regions. Their functioning conditions reveal often several contaminations. The Cheria carbonate aquifer (NE Algeria) has never had management tools to deal with the pollution of this resource. The outlining and protection of the vulnerable areas are essential to ensure the water purity and the consumer health. Based on the EPIK multicriteria analysis method, we aim in our study to assess the karstic aquifers intrinsic-vulnerability to contamination in the Cheria Plateau. This method has been already applied for contamination problems in Northeast Algeria. It uses a conceptual scheme that considers epikarst, protective cover, infiltration, and karst network as parameters. In addition, it also uses the interpolation of the geophysics data to define the conditioning attributes. The resulting vulnerability map categorizes all the basin vulnerable areas and the groundwater protection zones. Nearly 30% of the study area was judged as highly vulnerable to anthropogenic pollution, whereas around 10% is moderately vulnerable. These results confirm that the karst aquifer of the Cheria Plateau is severely polluted by chemical pesticides resulting from farming activity. In addition to the surrounding agricultural lands, the underground of Cheria city was found as extremely vulnerable to pollution ( F < 19). Our study delimited boundaries for the karst aquifer protection zones and for an integrated resource management in this region. It recommends applying this method for comparable problems.