Simulation of coastal groundwater remediation: the case of Nardò fractured aquifer in Southern Italy

Abstract

A new theoretical approach for evaluating the sharp interface position in a fractured aquifer was applied to the Nardò aquifer (Southern Italy). The results, based on Dupuit and Ghyben–Herzberg approximations, clearly show both the extent of seawater intrusion and how the latter can be reduced by means of artificial recharge. The new methodology describes a simplified mathematical formulation based on the sharp freshwater–saline interface in a fractured aquifer, rather than solving complicated density dependent partial differential equations of flow and solute transport in porous media. Application of the method requires, in a preliminary stage a knowledge of the freshwater flow rates in the fractured media. This can be derived by means of specific computational codes, under steady conditions. In the second stage, the extent of seawater intrusion can be evaluated in vertical planes of a three-dimensional domain. The methodology was applied to the Nardò fractured rock aquifer in order to estimate the extent to which seawater had intruded into it. The procedure was easily implemented in a job file of EXCEL Microsoft Office and performed well. Results indicated a good correlation between the coastal spring zones of the model with Landsat Thematic Mapper sensor photos and field investigation.