Estimating groundwater discharge in the oligohaline ecotone of the Everglades using temperature as a tracer and variable-density groundwater models

Author

Victora Spence, University of South FloridaFollow

Graduation Year

2011

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Geology

Major Professor

Mark C. Rains, Ph.D.

Committee Member

Mark Stewart, Ph.D.

Committee Member

Sarah Kruse, Ph.D.

Keywords

SUTRA-MS, finite-element modeling, Shark Slough, Taylor Slough, marine-derived phosphorus

Abstract

Recent research suggests that brackish, marine-derived groundwater up-wells in the oligohaline ecotone of the coastal Everglades, bringing with it phosphorus to an otherwise phosphorus-poor environment. The purpose of this study is to estimate the rates and timing of the groundwater discharge by using variable-density groundwater models constructed, calibrated, and validated with field measurements of hydraulic head and surface and subsurface temperature. Modeled groundwater discharge rates ranged from 5.4E-04 mm/day in August to -1.3E-03 mm/day in June for Shark Slough and 4.8E-01 mm/day in June to -1.4E-01 mm/day in January for Taylor Slough, where positive values imply groundwater discharge and negative values imply groundwater recharge. These results indicate that groundwater discharge rates during the period of study were low and perhaps a negligible source of marine-derived phosphorous in the oligohaline ecotone of Shark Slough but much higher and perhaps significant source of marine-derived phosphorous in the oligohaline ecotone of Taylor Slough.

Scholar Commons Citation

Spence, Victora, "Estimating groundwater discharge in the oligohaline ecotone of the Everglades using temperature as a tracer and variable-density groundwater models" (2011). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/3361