Assessment of Seawater Intrusion in a Coastline City Using GIS (Tripoli Lebanon)

Abstract

This paper evaluates the impact of seawater intrusion on the Miocene aquifer that covers the area of Tripoli. The existing aquifer, located under the city of Tripoli, spanning from Abou Samra hill toward the Mina shoreline, suffered a severe reduction of the stored water volume due to the unplanned urban expansion, the increase in water demand, the random drilling of wells and the untreated wastewater that spills exactly in front of Tripoli coastline. All these factors combined led to the saline water intrusion due to the reverse injection flow from the sea toward lower emptied cavities onshore. This has in turn led to a severe deterioration in the water quality of Tripoli city. To assess the current situation, a field survey was conducted to collect and gather underground water samples from various sites across the city and its surroundings in an attempt to analyze the Miocene aquifer of the North Governorate. The Geographic Information System was used as the main tool to both investigate and visualize the hydrophysical, hydrochemical, microbial onshore and water levels of the collected samples in the studied region. The maps generated using GIS constituted visual aids to support decisions regarding the sustainable development and management of groundwater.