Numerical model of porewater fluxes in a hypothetical mud island
- Univ. of South Florida, Tampa, FL (United States). Geology Dept.
The barely emergent circular islands of Florida Bay consist of a low-permeability aragonite mud overlying a high-permeability limestone that is hydraulically connected with the bay. An ephemeral pond, which forms when tides are above a low-lying berm that surrounds the island, increases in density because of intense evaporation. As a result, porewater in the island can be expected to flow downward through the sediments in response to a topographic drive, which results from the elevated level of the pond, and a variable-density drive due to the higher densities of the pond water. Porewater fluxes for an infinite-strip version of a Florida Bay mud island re obtained by numerical simulation using MODFLOW and MOCDENSE. Eight variables describe porewater flow through such an island: porewater flux (Q), cross-sectional width (w), pond length ([ell]), island length (L), depth to limestone (b), hydraulic conductivity of the mud and limestone layers (K[sub 1] and K[sub 2], respectively), and total head drive. These eight variables are reduced to five dimensionless variables; dimensionless flux (Q/K[sub 1]wL), hydraulic conductivity ratio (K[sub 2]/K[sub 1]), dimensionless head drive (T[sub D]/b), relative pond size ([ell]/L), and aspect ratio (L/b; which is held constant in this study with a value of 56). The results of the dimensionless relationships can be used to assess the porewater flux in islands resembling those of Florida Bay.
- OSTI ID:
- 6786349
- Report Number(s):
- CONF-9404221-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 26:4; Conference: 43. annual meeting of the Southeastern Section of the Geological Society of America, Blacksburg, VA (United States), 7-8 Apr 1994; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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