In order to effectively implement a model of the C-111 flow system it is essential to quantify its relevant flow-controlling properties. Special projects of the SFEP, such as the High Density Elevation Data Collection, Land Characterization from Remote Sensing, Vegetation Classification, and High Resolution Bathymetry projects, are employing advanced mapping techniques and products to collect and interpret data defining topographic patterns and land-surface features. Road embankments, canal levees, and overbank areas and features such as culverts, canal geometry, and hydraulic-control structures are being surveyed by precise laser-leveling methods and referenced to common horizontal and vertical datums. Mangroves and other areas of dense vegetation that present unique mapping difficulties are being mapped by newly developed and refined helicopter-based GPS techniques. In addition, flow levels and rates, needed for model calibration and for the conduct of numerical simulations, are being determined by other SFEP projects, such as the Freshwater Discharge to Florida Bay and Flow Transect Measurement projects, using conventional and advanced acoustic instrumentation and methods.
The capability of a mathematical model to simulate flow and transport in a complex environment such as the south Florida ecosystem is highly dependent on its representation of important forces and processes. The generic model being enhanced and further developed for the wetlands of the south Florida ecosystem numerically solves the vertically-integrated equations of mass, momentum, and constituent transport in shallow bodies of water. The model accounts for wetting and drying due to hydrologic and hydraulic processes and allows for the hydraulic controls of culverts, structures, and other physical flow barriers. Of particular concern in the C-111 flow system are representation of precipitation from rainfall, frictional effects due to vegetation, driving forces of winds, and losses by evapotranspiration and ground-water infiltration. New techniques for expressing these processes in the generic simulation model are being investigated and data-collection efforts by complementary projects of the SFEP, such as the Vegetative Resistance to Flow, Wind Effects on Flow, Evapotranspiration Measurements, and SW/GW Exchange projects, are seeking improved equation representations founded on field-defined parameters. As new expressions for these processes are defined, numerical approximations are developed and validation tests are conducted against field-measured parameters. Tests are typically also made using known analytical solutions if existent and, eventually, using fine-scale grids of limited canal and wetland areas for which detailed data can be collected and controlled numerical experiments designed.
Comprehensive sets of data are required for model implementation, process definition, boundary-condition resolution, and calibration. Data defining the physical properties and hydrologic processes of the C-111 flow system are presently being compiled, evaluated, and processed for model development-these include data sets describing vegetation characteristics; wetland elevations; canal geometry; embayment bathymetry; hydraulic control features such as road embankments, canal levees, culverts; etc. Flow data are also being collected to yield a set of hydraulic conditions that is representative of the range of flow exchanges between C-111 and wetlands to the southwest. These data are collected along 9-12 transect lines normal to the canal beginning at culvert and other strategic features and extending 1.5 km into the wetlands. Flow velocities are measured using portable acoustic meters, having accuracies of less than 1 mm/sec, retrofitted with advanced electronic compasses to geodetically reference flow directions. Concurrently, data defining critical hydrologic processes are also collected and(or) compiled from local field monitoring stations operated by other SFEP projects, State, or Federal Agencies. All of these data sets are being consistently referenced, systematically organized, and universally transformed into areal coverages for visualization and interpretation within the context of a GIS system being developed and enhanced specifically in support of model development and implementation.