A New Focus on Groundwater–Seawater Interactions (Proceedings of Symposium HS1001 at IUGG2007, Perugia, July 2007). IAHS Publ. 312, 2007, 334-342

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Effect of tidal fluctuations on contaminant transfer to the ocean

Ivana La Licata¹, Christian D. Langevin² & Alyssa M. Dausman²

1 Dipartimento di Ingegneria Idraulica Ambientale e del Rilevamento (D.I.I.A.R.), Politecnico di Milano, I-20133 Milan, Italy

ivana.lalicata@polimi.it

2 US Geological Survey, Florida Integrated Science Center, Fort Lauderdale, Florida 33315, USA

Abstract Variable-density groundwater flow was simulated to examine the effects that tide has on the coastward migration of a contaminant through a freshwater/saltwater interface and toward a coastal ocean boundary. Simulated ocean tides did not significantly affect the total contaminant mass input to the ocean; however, the difference in tidal and non-tidal simulated concentrations could be as much as 15%. It may be possible to numerically approximate the tidal-driven hydraulic transients in transport models that do not explicitly include tides by locally increasing dispersivity.

Key words tidal variation; contaminant transport; density

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