『Abstract
Seawater intrusion into the shallow aquifer in the Syrian coast,
north of Latakia (Damsarkho, Ras Ibn Hani) and south of Tartous
(Al Hamidieh, Ein Zarka) was studied using hydrochemical and isotopic
techniques. The electrical conductivity (EC) distribution map
north of Latakia revealed that mixing in this area is the consequence
of a frontal intrusion of seawater within the fresh groundwater
aquifer which, in turn, results from intensive pumping since the
1960s which has lowered the water table inland below sea level.
In Ein Zarka, south of Tartous, in contrast, the EC distribution
revealed that seawater intrusion is due to local up-coning as
a result of intensive pumping. The deuterium and oxygen-18 relationship
is that of a mixing line with a slope of 5.55, indicating an intrusion
between freshwater and seawater. In addition, the relationship
between oxygen-18 and chloride reveals that the mixing has a dominant
role compared to evaporation process. The mixing ratios are estimated
to be between 6 and 10％ north of Latakias, while they do not exceed
3％ south of Tartous. A tritium model was applied to compute the
“mean transit time”, which is estimated to be around 10 years,
on average, to reach the equilibrium that existed originally between
the fresh groundwater and seawater, provided that severe pumping
is completely halted and the aquifer is naturally recharged by
rainfall and deep percolation of irrigation water, thereby allowing
the restoration of the hydraulic gradient.
Keywords: Environmental isotope; Mediterranean; Mixing ratio;
Seawater intrusion; Syria; Transit time』
Introduction
Environmental background
Hydrogeology of the shallow aquifer
Northern Latakia
South Tartous area
Chemical characteristics
Electrical conductivity maps
Northern Latakia area
Southern Tartous area
Chemical analyses
Piper diagram
Isotopic analyses
The relation between deuterium and oxygen-18
The relationship between δ18O and chloride
Mixing ratios between fresh and saline water
Groundwater transit time estimation
Conclusion
Acknowledgments
References