While seawater intrusions are widely discussed, the salinization of coastal aquifers via narrow rivers is hardly documented. This study investigates groundwater dynamics in an aquifer next to an estuarine stream on the eastern Mediterranean coast. Groundwater levels and salinization patterns were examined as a response to dynamic changes in estuary water, both in low-and high-permeability aquifer units. In the high-permeability unit, the extent of salinization was relatively constant, reaching a distance of at least 80 m from the river, with no long-term changes in fresh-saline interface depth, indicating that the system is in a quasi-steady state. Groundwater salinity in the low-permeability unit showed frequent and large fluctuations (up to 36 and 22 at 5 and 20 m from the river, respectively). We suggest that the river may have a more immediate impact on a low-permeability than on a high-permeability aquifer. This is dependent on the history of seawater encroachments to the river, which are better preserved in the low-permeability unit, and on the hydrogeology of this unit, where sand lenses can serve as high-permeability conduits. However, this unit can efficiently prevent a large extent of salinization of the regional coastal aquifer by the estuary water.
Bibliographical noteFunding Information:
The authors wish to thank Hallel Lotzky, Iyad Swaed, Yoav Boaz, Alon Moshe, Yael Neumeier, Yona Geler, Avishai Abbo, Elisheva Refaeli, Yakov Mizrachi, Chaim Hemo, and Shlomo Askenazi from the Geological Survey of Israel and the Hebrew University for their help in the field and lab work. We owe gratitude to Dov S. Rosen and Lazar Raskin from the Israel Oceanography and Limnological Research (IOLR) Institute for providing data on sea level and wave height, and to Yaron Gertner (IOLR) for his assistance in the field. We also wish to thank Yariv Malichi, David Keren, and Eran Starous from the Israel Nature and Parks Authority for issuing the work permits for the Alexander River. This work was supported by the Israel Science Foundation grant No. 1527/2008. The first author is also grateful to the Israel Ministry of Science for granting him the Eshkol scholarship. This research was funded by the Israel Science Foundation grant No. 1527/2008. The first author is also grateful to the Israel Ministry of Science for granting him the Eshkol scholarship.
© 2019 by the authors.
- Estuarine river
- Fresh-saline water interface
- Seawater intrusion
- Surface-groundwater interaction
ASJC Scopus subject areas
- Geography, Planning and Development
- Aquatic Science
- Water Science and Technology