Abstract:
To simulate the effect of hydraulic barriers and underground structures on the flow system a hydrogeological numerical modeling was applied in the alluvial coastal aquifer of Alcântara (Lisbon). The groundwater dynamics was simulated using MODFLOW 2000, a 3D finite differences code. The modeled area, with 1.34 km2, and was discretized into 10 x 10 m cells in x and y directions, and 3 layers of variable thickness in the z direction. The model calibration was concluded for steady state and transient state conditions (considering tidal fluctuations). After calibration, combined extreme events were simulated (maximum recharge and pluvial discharges, and high tides). The result indicates changes in flow direction and increase on local groundwater levels due to underground structures. The modeling processes allowed identifying sensitive areas for the construction of new structures.
