Project number: 438416500

Continuing Project Work Plan - FY 1999

IDENTIFYING INFORMATION
Project title: Canal and Wetland Flow/Transport Interaction
Geographic area: South Florida
Project start date: January 1995
Project end date: September 1999

Project chief: Raymond W. Schaffranek
Region/Division/Team/Section: Eastern/Water Resources/National Research Program
Email: rws@usgs.gov
Phone: (703) 648-5891
Fax: (703) 648-5484
Mail address: National Center, MS 430, 12201 Sunrise Valley Drive, Reston, VA 20192

Program(s): South Florida Ecosystem Program

Program/Element/Task: South Florida Ecosystem Program/Element 2: Modeling And Support Studies For Southern Inland Coastal Systems Of South Dade County (Including The Buttonwood Embankment)/Task 7: Canal And Wetland Flow/Transport Interaction

BACKGROUND NARRATIVES

Project Summary: Canals are a major water-delivery component of the south Florida ecosystem. They interact with surrounding flow systems and waterbodies, either directly through structure discharges and levee overflows or indirectly through levee seepage and leakage, and thereby quantitatively affect wetland hydroperiods as well as estuarine salinities. Flows exchanged between interconnected canals, wetlands, and coastal waterbodies also convey chemical constituents that can affect plant and animal life. Knowledge of this flow interaction, as well as the timing, extent, and duration of inundation that it contributes to, is needed to identify and eliminate any potential adverse effects of altered flow conditions and transported constituents on vegetation and biota. Comprehensive analytical tools and methods are needed to assess the effects of nutrient and contaminant loads from agricultural and urban run-off entering canals and thereby conveyed into connected wetlands and other adjoining coastal ecosystems. A numerical model capable of accurately simulating canal and wetland flow interactions, including coupled solution of constituent transport equations, can be invaluable in evaluating the effects of altered flows and transported constituents for development of sound management practices for restoration and preservation of the south Florida ecosystem.

Project Objectives and Strategy: Water distribution strategies and reconfiguration plans for the south Florida ecosystem must identify and account for potential adverse impacts of various system design alternatives. Coupled flow and transport simulation models are needed to assess the cause-and-effect relation of flow deliveries on changes in vegetation and biota in order to provide complete information for the formulation of sound water-management decisions. A simulation model can be used in advance to evaluate a proposed plan and thereby detect potential problems prior to implementation or it can be used as a tool to assess the effectiveness of an implemented system reconfiguration. The objectives of this project effort are to investigate the complex mechanisms governing canal and wetland flow transitions and to formulate highly accurate numerical techniques for the design, development, and demonstration of a coupled generic model to simulate the hydraulic and constituent transport properties of such interconnected flow systems. Project efforts are focused on development of the most representative numerical techniques and boundary condition approaches to effect coupled solution of hydrodynamic and transport equations at space and time scales consistent with the physical processes where transitions from streamlike canal to wetland sheet flows occur and constituent exchanges take place. Specific efforts are focused on evaluation, enhancement, and integration of existing flow and transport models for coupled simulation of canal and wetland interactions followed by preliminary sensitivity testing and demonstration of model capabilities using data from the C-111 canal and wetland drainage system. The C-111 canal between control structures S-18C and S-197, including culvert connections to northeast wetlands and overbank flows to southwest wetlands, which were previously directed through levee cuts, is the model study area. Conventional and newly-developed ground and aerial GPS surveying techniques are being employed to provide the basic data needed to depict the varied C-111 drainage basin bathemetry and hypsography at precision levels consistent with physical processes governing canal and wetland interactions. Acoustic velocity meters are being used to collect data defining flow patterns in and along the C-111 overbank area where transitions from canal to sheet flow occur. These data are being used to test and validate developed numerical algorithms.

Potential impacts and major products: A model and report documenting coupling procedures and numerical techniques appropriate for simulation of flow and transport conditions in interconnected canal and wetland systems, as typified by the C-111 drainage system, will be produced. Illustrative examples of model performance developed using the C-111 drainage system will give insight into the relative effectiveness of the recently completed levee-removal operation on enhancing the transition from canal to sheet flow in the southeast portion of Everglades National Park. The model will also have application potential for evaluating the flow/salinity relationship and the transport of nutrients and other constituents from the canal through the Everglades wetlands and subsequently into northeast Florida Bay.

Collaborators, clients: This project will integrate findings of the Evapotranspiration, Vegetative-Resistance, Wind-Effects, Groundwater/Surface-Water Exchange, Freshwater-Flows, Land Characteristics from Remote Sensing, and GIS-Interface projects to tailor the model development to processes relevant to the south Florida ecosystem. Findings and products of the NMD High Accuracy Elevation Mapping and GD Florida Bay and Sedimentation projects are relied on as input for model development and sensitivity testing. A model capable of accurately simulating canal and wetland interactions is a needed decision-making tool for water-management agencies such as the NPS, FWS, SFWMD, and USACE to both plan and evaluate restoration reconfigurations.

WORK PLAN

Time line (FY 1999 to project end): Project activities will focus on completion of processing and analysis of C-111 land-surface elevation and flow data, formulation of model coupling algorithms, development of demonstrative simulation scenarios, and generation of an initial draft of the model documentation report.

FY 1999 activities: Complete enhancement of individual canal and wetland modules focusing on development of internal and external boundary-condition treatment for transport simulation and model coupling. Finalize analysis of equation-term behavior and evaluation of various formulations and approximation techniques under varied temporal and spatial scales in conjunction with development of model-coupling algorithms. Incorporate solution of the salt-balance equation in the canal model for integration of the density-driven pressure gradient term. Complete development and demonstration of various simulation approaches and software systems, including ARC/GIS techniques for interfaces to remote sensing coverages, for pre-processing model input and post-processing model results using data from the C-111 drainage system. Finalize analysis and synthesis of data from the NMD High Accuracy Elevation Mapping project for determination of land-surface elevation and vegetation grid generation and from the GD Florida Bay and Sedimentation project for definition of coastal embayment bathymetry and bottom roughness coefficients. Extension and refinement of the preliminary C-111 model grid will be conducted to include synthesis of new survey data, e.g., from the Mangrove-Mapping effort and for the Royal Palm Ranger Station topographic quadrangles, as they become available. Compilation of data for the surrounding sub-embayments and tidal wetlands of Joe Bay, Long Sound, Manatee Bay, and Barnes Sound will continue. Compilation and processing of boundary-condition, flow velocity and water-level data for system quantification, as well as model calibration and verification, will be conducted for execution of various simulation scenarios to demonstrate model performance in evaluating C-111 canal/wetland flow exchanges.

FY 1999 deliverables/products: An initial draft report documenting formulation of the generic model and demon-strating its application to the C-111 drainage system will result from this work in FY 1999.

FY 1999 outreach: An oral presentation and paper describing the model development and application is planned for an international conference on Ecohydraulics to be held in 1999. Project efforts are discussed, both formally and informally as appropriate, with colleagues from client agencies, e.g., NPS, FWS, SFWMD, USACE, etc., at joint interagency and professional society meetings.

New directions or major changes for FY 1999: No new efforts or directions are planned.

ACCOMPLISHMENTS, OUTCOMES, PRODUCTS, OUTREACH

FY 1998 accomplishments and outcomes, including outreach: Developed interdisciplinary work plan, coordinated research activities, and conducted scientific review of the Mangrove Hydrologic Modeling program of the DOL Critical Ecosystem Studies Initiative, comprised of USGS South Florida Ecosystem projects.

FY 1998 deliverables, products completed: Abstract on project efforts prepared and presented at Technical Symposium in Ft. Lauderdale, August 25-27, 1997. Coordinated and chaired session on Modeling and Support Studies for Southern Inland and Coastal Systems. Organized technical sessions for South Florida Ecosystem project presentations at the 1999 Ecohydraulics Conference. Fact Sheet FS-0193-97, entitled A GIS Interface for Environmental System Analysis: Application to the South Florida Ecosystem, resulted from project efforts in FY98.

PROJECT SUPPORT REQUIREMENTS

Names and expertise of key project:
Raymond W. Schaffranek, Hydrologist
David W. Stewart, Computer Specialist

Other required expertise for which no individual has been identified:

Major equipment/facility needs:
 

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