Assessing the groundwater vulnerability to pollution using DRASTIC and SINTACS models, case study: Evan Plain, south west of Iran

Agricultural and industrial activities have affected the strategies of groundwater quality management during the past decades. Assessment of groundwater vulnerability potential is currently one of the most important devices in water resources management. During recent years, various methods for assessment of vulnerability potential have been developed such as mathematical models, statistical procedures and overlapping and ranking techniques. DRASTIC and SINTACS models are the two most popular overlapping index methods, utilized recently. Vulnerability potential evaluation of groundwater in Evan Plain was implemented applying DRASTIC and SINTACS models. Hydrogeological parameters including aquifer recharge, water table depth, hydraulic properties of the aquifer, surface topography and the soil properties were analyzed, utilizing the geographical Information system (GIS) to evaluate the susceptibility of the study area to groundwater pollution. The major portion of the Evan Plain has low to very low potential in DRASTIC model, whereas SINTACS model shows low to moderate potential of pollution. Sensitivity analysis of the models revealed that the topography parameter has the highest effect in vulnerability potential. Nitrate concentration was as the model calibration index. Nitrate concentration ranged between 8 to 33 mg/l in most parts of the Evan Plain, similar to SINTACS model results.