Introduction
The U.S. Geological Survey is one of several agencies participating in the scientific effort to provide knowledge that can help protect and preserve the ecosystem of south Florida. One project of the intergovernmental South Florida Ecosystem Program (SFEP) is focused on developing a computer model to simulate the flow of water and analyze the transport of waterborne chemical constituents between canals and wetlands. Quantification of dynamic flows within the south Florida ecosystem is vital to understanding the implications of the residence time of water, potentially nutrient-enriched (with nitrates or phosphates) or contaminant-laden (with metals or pesticides), that can alter plant life and affect biological communities. Nutrients carried in the water conveyed by canals draining agricultural areas and dispersed into wetlands by canal discharges, by levee overflows, or by seepage are considered to be a major contributor to changes in the types of vegetation found in the Everglades. Freshwater inflows, typically of varying magnitudes and durations, not only influence the salinity of Florida Bay but also potentially carry toxic substances that can affect and alter the Bay's aquatic biota. The simulation capability being developed within the SFEP can be useful for identifying approaches to alleviate adverse impacts of excessive or deficient flows and transported constituents. Through strategic use of a simulation model, cause-and-effect relations between discharge sources, flow magnitudes, transport processes, and changes in vegetation and biota can be investigated. The effects of driving forces on nutrient cycling and contaminant transport can then be quantified, evaluated, and considered in the development of remedial management plans.
