Characterization of maximum infiltration areas using GIS tools

The main goals of this study are the identification of maximum infiltration areas and the evaluation of aquifer vulnerability in order to delineate a protection strategy for municipal water supplies.A two-step methodology is implemented in Geographic Information System (GIS): (i) in the first step, hydrogeological parameters are classified by grades of infiltration and combined to delimit the most favourable aquifer recharge areas; (ii) in the second step, infiltration potential map obtained in previous step are merged with the hydrostatic water level depth layer and a final map indicator of aquifer vulnerability to potential contamination is presented.This methodology was implemented in ArcGis 8.2 software and applied to Seixal Municipality, an urban/industrial area near the capital of Portugal, Lisbon, where negative impact on groundwater resources is a major concern.