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Project Work Plan

Greater Everglades Science Program: Place-Based Studies

Project Work Plan FY 2003


Project Title: Tides and Inflows in the Mangrove Ecotone (TIME) Model Development
Project start date:October 1, 1999 Project end date: September 30, 2004
Project Funding: Place-based Studies
Principal Investigator: Harry L. Jenter
Email address:
Phone: 703 648-5916 Fax: 703 648-5484
Mail address: U.S.G.S.; 12201 Sunrise Valley Drive; Mail Stop 430, National Center; Reston, Virginia 20192

Other Investigator(s): Kevin Kotun
Email address:
Phone: 305 242-7829 Fax: 305 242-7836
Mail address: SFNRC; 40001 State Road 9336; Homestead, Florida 33034

Project Summary: A critical objective of the south Florida ecosystem restoration effort is to create and preserve ecological conditions that are consistent with habitat requirements. Two of the most important requirements for restoration success are an understanding of wetland hydroperiods and coastal embayment salinities. Hydroperiods in the southern Everglades, including duration, timing and extent of wetland inundation, have been distorted substantially in the past as evidenced by observed shifts in zoological and vegetative species. Similarly, embayment salinities have been altered with dramatic ecological effects.

Both regulatory and natural factors contribute to the definition of hydroperiods and salinities, making their precise evaluation and management difficult. The understanding and control of hydroperiods and salinities becomes even more problematic in the mangrove ecotone, the transition zone between the Everglades wetlands and coastal embayments where hydroperiods and salinities are inextricably linked and the mixing of fresh and salt water cannot be ignored. In this region, coastal tides, wetland flows and upstream inflows must be considered concurrently for an accurate understanding of their effects.

The Tides and Inflows in the Mangrove Ecotone (TIME) project entails a study of the transition region using a coupled surface-water/groundwater model and the collection and analysis of data in support of that modeling effort. The project described herein entails incorporation, into the TIME surface-water model, the understandings gleaned from the Southern and Inland Coastal Systems (SICS) study conducted in the Taylor Slough and C-111 Canal basins of Everglades National Park. Specifically, vegetative resistance and meteorological forcing process-study results are being incorporated into the TIME model. Because of the high demand for data in the parameterization of these results, this project also entails the assembly, storage and distribution of all time-variable data sets used to drive, calibrate and test the TIME surface-water model. This work also entails collaboration and data exchange with a number of other south Florida researchers.

Project Objectives and Strategy: The TIME Model Development project is focused on further developing, extending and implementing a mathematical model to study the interaction between wetland sheet flows and dynamic forces in the transition zone between the southern Everglades and its coastal embayments. The model will be used to study and evaluate the combined response of hydroperiods in the wetlands and salinities in the mangrove ecotone to inflow alterations. The project effort will include:

  1. monitoring hydrologic processes and dynamic forces to develop an improved understanding of them individually and of their interaction
  2. translating this information and prior knowledge of processes gleaned from the SICS project into improved empirical expressions and mathematical equations to better represent the processes both individually and collectively
  3. transforming these expressions and their correlation to ecosystem properties into numerical algorithms
  4. integrating theses algorithms into an existing numerical model framework
  5. implementing the model to the transition zone of the Everglades that encompasses the mangrove ecotone using collected data to define critical ecosystem properties such as land-surface elevations, vegetative characteristics, etc.
  6. calibrating the model using time series of water-level, flow and salinity data collected at strategic intermediate internal points and along the model boundaries
  7. documenting the model implementation and any findings that are critical to improved management of the ecosystem

Potential Impacts and Major Products: The major product of the TIME Model Development project will be a sound, physically-based, fine-resolution (500m) model of the Everglades National Park area of the Everglades consistent with the Across Trophic Level System Simulation models that can be used as a research tool and management model to study and evaluate ecosystem response to regulatory decisions. Through analysis of model results for varied inflows, cause and effect relationships to ecosystem functions and sustainability can be investigated to evaluate and guide restoration actions. Any external dynamic factors that could adversely affect restoration objectives can be identified and demonstrated. Data collected in support of the model development will be made available for dissemination via the Internet and scientific findings will be reported in traditional peer-reviewed literature as appropriate.

Collaborators: Ray Schaffranek, Christian Langevin, Eric Swain, Nancy Rybicki, John W. Jones



Title of Task 1: Incorporation of Vegetative Resistance and Meteorological Effects into the TIME Surface-water Model
Task Funding: PBS
Task Leaders: Harry L. Jenter
Phone: 703 648-5916
Fax: 703 648-5484
Task Status (proposed or active): Active
Task priority: High
Time Frame for Task 1: Continuing through FY 2004
Task Personnel: Harry L. Jenter and post-graduate intern

Task Summary and Objectives: The main objective of this task it to improve the TIME Surface-water Model by modifying the existing code in a way that more accurately represents the physics of vegetative resistance and meteorological forcing in shallow wetlands with emergent vegetation, specifically the mangrove ecotone of the Everglades. In order to accomplish this, limited field observations will be collected and analyzed, the large, flow and vegetation-characteristic datasets collected during the SICS project will be analyzed further, the Surface Water Integrated Flow and Transport 2-Dimensional (SWIFT2D) numerical model will be altered to incorporate improved physical representations and data sets for all relevant vegetative-resistance and meteorological factors will be assembled for the TIME Model Development initial calibration scenario: June, 1999 — August, 1999.

Work to be undertaken during the proposal year and a description of the methods and procedures:

Jenter and a Masters-degree-level intern will modify the SWIFT2D surface water model code to accept vegetation type and density data from John Jones' mapping project as an input dataset. The ability to use this dataset to calculate vegetative resistance for the model will be added as well. This resistance will be calculated based on the Stem-Reynolds-Number analysis of Lee, Roig and Jenter (submitted) and the statistical correlation of Roig, Rybicki and Jenter (in preparation). Initially, Maning's n values will be calculated in order for the model to maintain its original resistance formulation in unvegetated grid cells. However, a set of simplified model runs with be conducted with a test grid in order to explore alternative resistance formulations such as Darcy-Weisbach or direct specification of the frictional force. A final decision on the formulation to be used in the TIME model will be made in FY2004.

The model will also be modified to accept hourly time-dependent wind data and to calculate time- and space-dependent wind stress. These data will be interpolated from data archived in the TIME Data System (see Task 2 below). The model has been modified already to use a wind sheltering coefficient to calculate wind stress based on wind speed, the equivalent wind stress over unvegetated waters and a constant sheltering coefficient from the literature. This formulation will be refined to allow for spatial variation in the sheltering coefficient based on assignment of grid cells using John Jones' vegetation mapping data as input. Assignment will be based on findings from Jenter and Duff (1999) and from information derived from analysis of simultaneously deployed meteorological towers and profiling current meters at two locations within the Everglades: one in Water Conservation Area 3A and one in southern Shark Slough. Jenter and the intern will maintain these sites and analyze the data in order to apply the analysis to the wind sheltering specification in the model. These sites were installed in FY2002 and are expected to yield extremely useful information for the TIME modeling effort.

Planned Outreach: Results from this task will continue to be published in the relevant peer-reviewed literature when appropriate, and will be presented at the Greater Everglades Ecosystem Restoration (GEER) conference in Spring, 2003.

Title of Task 2: Assembly, Storage and
Task Leaders: Harry L. Jenter and Kevin Kotun
Task Funding: PBS
Phone: 703 648-5916
Fax: 703 648-5484
Task Status (proposed or active): Active
Task priority: High
Time Frame for Task 2: Continuing through FY 2004
Task Personnel: Harry L. Jenter, Kevin Kotun and post-graduate intern

Task Summary and Objectives: The main objective of this task is to improve and support the TIME surface-water model by assembling, quality-assuring and archiving all relevant datasets for the model development and by maintaining a project website through which these data can be distributed Over 30 datasets are required at present to drive the model. Additionally, more than 200 datasets can be used to calibrate and assess the model. These datasets have been assembled into an archive from which data can be extracted. This archive, known as the TIME Data System (TDS), has been made accessible via the Internet at It is intended that the TDS contain all relevant data spanning the range 1995 to present. Therefore, the datasets must be updated frequently as new information becomes available or additional historical data is found. Data also must be quality assured as they have been collected from a variety of sources. Lastly, tools for extracting, viewing, analyzing and reformatting the data must be created to support the model development.

Work to be undertaken during the proposal year and a description of the methods and procedures:

The primary goal for this task in FY2003 is to produce all of the necessary data sets for the calibration period of the TIME surface-water model. Data from June, 1999 through August, 1999 will be extracted from the TIME Data System, carefully scrutinized, gaps will be filled through interpolation if necessary, and the data will be formatted for input into the model. All data will be interpolated temporally to match the model time step. Some of the datasets described in Task 1 will require spatial interpolation as well. Specifically, maps of hourly wind speed, wind direction and rainfall will be produced from data in the TIME Data System for the calibration period. Jenter and a Bachelor's-degree-level intern will establish algorithms for this interpolation and will implement those algorithms as computer programs for the automatic creation of model input data. An effort will be made to automate much of the process of extracting data from the TDS, quality assuring, interpolating and reformatting it for use in the model in order to make both the TDS and the model easier to use for future applications. The TDS will be documented thoroughly in a USGS Open-file report in FY2003.

A secondary goal for this task in FY2003 will be to assure that the entire TDS database from 1995 to present is quality assured and as complete as possible. The intern will be responsible for reviewing each of the over 200 datasets in the TDS. The intern will work closely with Kotun to ensure that the NPS data sets in the TDS are as up-to-date as possible. The web interface for the TDS will be modified in order for a simple and concise report of data completeness to be produced for arbitrarily specified time periods. The data-extraction scripts of the TDS will be modified to offer interpolation of missing data in order for the user to receive a gap-free dataset which can be more easily used as model input or for other purposes.

Planned Outreach: Results from this task will continue to be published in the relevant peer-reviewed literature when appropriate, and will be presented at the Greater Everglades Ecosystem Restoration (GEER) conference in Spring, 2003.

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Last updated: 09 April, 2014 @ 12:18 PM (KP)