A GIS-based Assessment of the Vulnerability to Potential Pollution of the Alluvial Aquifer of Aousja-Ghar El Melh (North-East of Tunisia) Using the Parametric Method DRASTIC

Abstract

The phreatic aquifer of Aousja-Ghar El Melh (governorate of Bizerta, northeast of Tunisia), has a great economic weight as it is tightly linked to irrigation and domestic consumption. The aquifer area is found mostly in agricultural zones where more and more chemical fertilizers are being used. Such chemical fertilizers, alongside industrial zones discharges appearing for the last 25 years, put at risk ground waters quality. The DRASTIC method has been applied to study the extent to which the aquifer has been affected by generic pollutants. This method hinges on GIS techniques. The result suggests a map with evidence for three degrees of vulnerability: low, moderate, and high. Evidence shows the predominance of moderate vulnerability in most of Aousja-Ghar El Melh aquifer, which occupies an area of 45%. Low and high groundwater vulnerability occupy 28% and 27% of the total surface of the studied area, respectively.