Numerical simulation of the effect of the sloping submarine outlet-capping on tidal groundwater head fluctuation in confined coastal aquifers

Shuang Liu, Hailong Li, Michel C. Boufadel, Guohui Li

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

The submarine outlet of a coastal confined aquifer is usually covered by less-permeable material such as silt and fine sand which forms a sloping or almost flat seabed. Previous analytical studies of the tide-induced head fluctuation usually assumed a vertical interface between the outlet-capping and the seawater and neglected the effects of the outlet-capping's slope. Here we conducted a series of numerical simulations to investigate the effect of the slope of the outlet-capping on the tide-induced head fluctuations in a coastal confined aquifer. The numerical simulations demonstrated that when the hydraulic diffusivity, slope and/or the outlet-capping leakance are large, the tidal loading effect is relatively weak and the leakance dominates. In this case the analytical solution applies. In general, the joint actions of the outlet-capping leakance and the tidal loading effects result in complicated, 2-dimensional flow in the aquifer near the shoreline. For aquifers with small hydraulic diffusivity, small slope and/or small outlet-capping leakance, the outlet acts approximately as a no-flow boundary condition and the tidal loading dominates. In this case, negative phase shifts (time-advance) may occur near the coastline. The study provides potential guide to infer the aquifer's submarine structure and parameter from tidal head fluctuation observations in inland wells.

Original languageEnglish (US)
Pages (from-to)339-348
Number of pages10
JournalJournal of Hydrology
Volume361
Issue number3-4
DOIs
StatePublished - Nov 15 2008
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Water Science and Technology

Keywords

  • Coastal confined aquifer
  • Loading efficiency
  • Numerical simulation
  • Sloping submarine outlet-capping
  • Tide-induced head fluctuation

Fingerprint Dive into the research topics of 'Numerical simulation of the effect of the sloping submarine outlet-capping on tidal groundwater head fluctuation in confined coastal aquifers'. Together they form a unique fingerprint.

Cite this