Assessment of groundwater vulnerability by combining drastic and susceptibility index: Application to Annaba superficial aquifer (Algeria)

Abstract

Groundwater pollution due to anthropogenic activities is one of the major environmental problems in urban and industrial areas. The aim of this work is to propose a new integrated methodology to assess actual and forecasted groundwater vulnerability by combining Drastic and susceptibility index. The contamination susceptibility index (SI) at a given location was calculated by taking the product of the vulnerability DRASTIC index (VI) and the quality index (QI): SI=VI x QI. The superficial aquifer of Annaba plain was the study case proposed for the application of this methodology. The study revealed that the area with Very High vulnerability would increase 73 % in this superficial layer. This result can be explained by the susceptibility index map shows both hydrogeological and hydrochemical data related to the contamination problem including areas that should be taken into consideration during water management planning. The index map indicates that the most susceptible groundwater is occupies the majority of the study area. The validity of the DRASTIC and the susceptibility index methods, verified by comparing the distribution of some pollutants (Daouad, 2013) in the groundwater and the different vulnerability classes, shows a high contamination that affect the water quality in study areas.