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Reference Category Journals
DOI 10.1002/hyp.13863
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Title (Primary) Investigation of the elevation of saltwater wedge due to subsurface dams
Author Chang, Q.; Zheng, T.; Chen, Y.; Zheng, X.; Walther, M.
Source Titel Hydrological Processes
Year 2020
Department ENVINF
Volume 34
Issue 22
Page From 4251
Page To 4261
Language englisch
Keywords field‐scale numerical model; seawater intrusion; subsurface dam; hydraulic gradient; freshwater discharge; saltwater contaminated area; elevation of saltwater wedge; groundwater resources
Abstract Subsurface dams are rather effective and used for the prevention of saltwater intrusion (SWI) in coastal regions around the world. We carried out the laboratory experiments to investigate the elevation of saltwater wedge after the construction of subsurface dams. The elevation of saltwater wedge refers to the upward movement of the downstream saltwater wedge because the subsurface dams obstruct the regional groundwater flow and reduce the freshwater discharge. Consequently, the saltwater wedge cannot further extend in the longitudinal direction but rises in the vertical profile resulting in significant downstream aquifer salinization. In order to quantitatively address this issue, field‐scale numerical simulations were conducted to explore the influence of various dam heights, distances, and hydraulic gradients on the elevation of saltwater wedge. Our investigation shows that the upward movement of the saltwater wedge and its areal extension in the vertical domain of the downstream aquifer become more severe with a higher dam and performed a great dependence on the freshwater discharge. Furthermore, the increase of the hydraulic gradient and the dam distance from the sea boundary leads to a more pronounced wedge elevation. This phenomenon comes from the variation of the freshwater discharge due to the modification of dam height, location, and hydraulic gradient. Large freshwater discharge can generate greater repulsive force to restrain the elevation of saltwater wedge. These conclusions provide theoretical references for the behavior of the freshwater‐seawater interface after the construction of subsurface dams and help optimize the design strategy to better utilize the coastal groundwater resources.
Persistent UFZ Identifier
Chang, Q., Zheng, T., Chen, Y., Zheng, X., Walther, M. (2020):
Investigation of the elevation of saltwater wedge due to subsurface dams
Hydrol. Process. 34 (22), 4251 - 4261 10.1002/hyp.13863