Assessing Groundwater Vulnerability to Contamination in a Semi-Arid Environment Using DRASTIC and GOD Models, Case of F’kirina Plain, North of Algeria
Résumé
Groundwater is vulnerable to contamination by anthropological activities. Vulnerability mapping is
considered as a fundamental aspect of groundwater management. The aim of this study was to estimate aquifer
vulnerability by applying the DRASTIC and GOD models in F’kirina agricultural plain northern Algeria. The
DRASTIC model uses seven environmental parameters (depth to water, net recharge, aquifer media, soil media,
topography, impact of vadose zone, and hydraulic conductivity) to characterize the hydrogeological setting and
evaluate aquifer vulnerability. GOD is an overlay and index method designed to map groundwater vulnerability
over large regions based on three parameters (groundwater confinement, overlying strata, and depth to
groundwater). The information layers for models were provided via geographic information system. The results
showed that the DRASTIC model is better than GOD model to estimate groundwater vulnerability to pollution
in the measured wells. For DRASTIC model, the correlation coefficient between vulnerability index and nitrate
concentration was 68 % that was substantially higher than 28 % obtained for the GOD model. We can conclude
that nitrate concentration should be a suitable parameter to investigate the accuracy of the DRASTIC and GOD
models.