Gregory Noe; James Saiers
To quantify through detailed field experiments previously unstudied processes in the Everglades, such as rates of fine-particle movement and filtration by vegetation as well as advective solute exchange between surface water and zones of solute storage in relatively stagnant waters (in areas of thick vegetation and in peat pore water). Our study focuses on determining the effects of these processes on chemical reactions of the contaminants as well as overall effects on downstream transport. At least initially, the emphasis will be on improved understanding of factors influencing transport of dissolved and fine particle forms of phosphorus.
To apply the new knowledge gained from field measurements first in our own transport models (which are necessarily limited in time and space) and then to encourage application in more widely used water-quality models (e.g. DMSTA, ELM), and water quality models currently in development (e.g. extension of USGS SICS model in Taylor Slough). The goal is more accurate simulation of the effects of restoration on Everglades water quality, thus allowing more reliable use of water-quality models for prediction of the effects of restoration.
To guide the use of improved water-quality models to estimate potential rates of transport, storage, and remobilization of phosphorus (and other contaminants) in WCA-2A, Shark and Taylor Sloughs in Everglades National Park, and Loxahatchee Wildlife Refuge, with a goal to predict potential rates of downstream movement of phosphorus in these systems under "restored" flows.
Scinto, L. J.; Taylor, J.; Childers, D. L.; Jones, R. D.
Saiers, J. E.; Newlin, J. T.
Harvey, Judson W.; Mylon, Steven E.
Trexler, J. C.; Richards, J. H.; Childers, D. L.; Lee, D.; Edwards, A. L.; Scinto, L. J.; Jayachandran, K.; Noe, G. B.; Jones, R. D.
Newlin, J. T.; Krest, J. M.; Choi, J.; Nemeth, E. A.; Krupa, S. L.
Childers, Daniels L.
Harvey, J. W.
1. Interpret regional patterns in physical properties and chemistry of fine suspended particles that were measured in FY 2005 in a regional program of sampling in the Everglades that contrasted wetlands with different levels of hard and soft water and contrasting impacts of phosphorus pollution. The variables measured were total concentration, size distribution, elemental composition, phosphorus content of particles in the water column. Locations included one site in central Arthur R. Marshall Loxahatchee (WCA-1), three sites along the nutrient enrichment gradient in WCA-2A, and one site in Shark Slough, Everglades National Park.
2. Monitoring of phosphorus fate and storage in an area of well preserved ridge and slough landscape in Water Conservation Area 3A. This work will investigate interactions between topography, flow velocity, vegetation type and density, and the transport of fine suspended particulates and associated phosphorus over a wet season. Two monitoring sites will be established (one on a ridge and one in a slough) with continuous measurement of water depth, velocity, specific conductivity, and temperature profiles in the water column. At the same sites this project will be measuring detailed topography and microtopography, and sediment characteristics (including phosphorus forms) at the ridge and slough sites and at transition sites between them. On a one time sampling trip we will measure storage of nutrients in dissolved and particulate phases in water, soil, and plants across the transect. On a monthly basis through the wet season we will measure dissolved and suspended fine particulate concentrations of phosphorus and nitrogen (organic and inorganic forms) at three depths of the water column in both ridge and slough. Dissolved and particulate organic carbon, calcium, iron, and aluminum will also be measured at the same locations on one sampling trip Dissolved concentrations will also be determined at six depths in pore water of the Everglades peat soil.
3. In addition to seasonal monitoring, interactions between water flow, suspended sediment transport, and phosphorus biogeochemistry will be addressed through carefully controlled injections of solute and particulate tracers. The goal is to determine in detail (1) the fate of solutes and fine particulate matter under different flow conditions in contrasting ridge and slough environments, and (2) to identify the specific physical and biological features and processes responsible for the observed levels of transport and storage. These detailed experiments are to be conducted at the spatial scale of approximately 10 m and the time scale of several days. Results of those experiments must be modeled to summarize in an efficient manner the parameters describing (1) interactions between particle sources, size classes, and phosphorus content, (2) transport and filtration rates of particles in areas of contrasting type and density of vegetation, (3) rates of water and solute storage in relatively slow moving water in zones of thick vegetation and in subsurface pore water, and (4) chemical reaction rates that change the form of phosphorus (between dissolved and particulate) and affect the residence time of phosphorus in storage and the mobility of phosphorus in forms that can be transported. This information is critical for guiding the development of water quality models which must include acceptable simplifications of the complex processes affecting phosphorus fate and storage in the Everglades.
U.S. Department of the Interior, U.S. Geological Survey
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