Impact of Demographic Growth on Seawater Intrusion: Case of the Tripoli Aquifer, Lebanon

Abstract

Water resources in Mediterranean coastal aquifers are subject to overexploitation leading to an increase in seawater intrusion. Based on the United Nations Environment Program, "UNEP" 75% of people in the world will live in coastal cities by 2020. This is having a major impact on the salinization process. This paper deals with the impact of demographic evolution on seawater intrusion and considers the case of the lower Tripoli aquifer in Lebanon. A numerical model based on the sharp interface approach is implemented using "Freefem++" to access the seawater intrusion. The model is verified against an analytic and a numerical solution. It is calibrated and validated against hydraulic head observations (RMSD = 0.819 m). Then several scenarios of pumping are applied based on available demographic growth rates to quantify the impact on seawater intrusion. The projection scenarios show that if the current pumping rates are maintained while maintaining the demographic evolution, the pumping wells will be salinized within 2 decades in the highly populated areas.

Assessing the Contribution of Demographic Growth, Climate Change, and the Refugee Crisis on Seawater Intrusion in the Tripoli Aquifer

“…The Figure 2. Geological map and stratigraphy of Tripoli, after Kalaoun et al (2016) [12]. 3 per year, while the discharge is about 75.9 M m 3 per year [11].…”

“…60% of the freshwater need is covered by groundwater sources. The electrical conductivity measured in several wells shows the scale of the salinization in the studied zone [11,12].…”

“…More recently, Kerrou et al [6] investigated and predicted the situation of seawater intrusion in the Korba aquifer in Figure 1. Location map of rivers, watersheds, study area, and well positions, after Kalaoun et al (2016) [12]. [12].…”

“…Location map of rivers, watersheds, study area, and well positions, after Kalaoun et al (2016) [12]. [12].…”

Snow observations in Mount Lebanon (2011–2016)

“…Water scarcity is a growing concern in Lebanon due to the unsustainable water resource management, the limited accessibility to the water sources, increasing water demand by all sectors, increasing water pollution, and sea water intrusion (MOEW, 2010;UNDP, 2014;Kalaoun et al, 2016). Lebanon receives on average 830 mm of precipitation per water year (September-August) (MOEW, 2010).…”