Peat porewater chloride concentration profiles in the Everglades during wet/dry cycles from January 1996 to June 1998: field measurements and theoretical analysis |
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Authors: | Michael M. Reddy Micaela B. Reddy Kenneth L. Kipp Aaron Burman Paul Schuster Peter S. Rawlik Jr. |
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Affiliation: | 1. US Geological Survey, Water Resources Division, PO Box 25046, Denver, CO 80225, US;2. Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, US;3. US Geological Survey, Water Resources Division, 3215 Marine Street, Boulder, Colorado 80303, US;4. South Florida Water Management District, West Palm Beach, Florida 33416, US |
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Abstract: | Water quality is a key aspect of the Everglades Restoration Project, the largest water reclamation and ecosystem management project proposed in the United States. Movement of nutrients and contaminants to and from Everglades peat porewater could have important consequences for Everglades water quality and ecosystem restoration activities. In a study of Everglades porewater, we observed complex, seasonally variable peat porewater chloride concentration profiles at several locations. Analyses and interpretation of these changing peat porewater chloride concentration profiles identifies processes controlling conservative solute movement at the peat–surface water interface, that is, solutes whose transport is minimally affected by chemical and biological reactions. We examine, with an advection–diffusion model, how alternating wet and dry climatic conditions in the Florida Everglades mediate movement of chloride between peat porewater and marsh surface water. Changing surface water–chloride concentrations alter gradients at the interface between peat and overlying water and hence alter chloride flux across that interface. Surface water chloride concentrations at two frequently monitored sites vary with marsh water depth, and a transfer function was developed to describe daily marsh surface water chloride concentration as a function of marsh water depth. Model results demonstrate that porewater chloride concentrations are driven by changing surface water chloride concentrations, and a sensitivity analysis suggests that inclusion of advective transport in the model improves the agreement between the calculated and the observed chloride concentration profiles. Published in 2007 by John Wiley & Sons, Ltd. |
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Keywords: | Everglades peat porewater diffusion advection transport mathematical model chloride transport |
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