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Environmental Fluid Dynamics Code (EFDC)

The Environmental Fluid Dynamics Code (EFDC Hydro) is a state-of-the-art hydrodynamic model that can be used to simulate

aquatic systems in one, two, and three dimensions. It has evolved over the past two decades to become one of the most widely

used and technically defensible hydrodynamic models in the world. EFDC uses stretched or sigma vertical coordinates and

Cartesian or curvilinear, orthogonal horizontal coordinates to represent the physical characteristics of a waterbody. It solves threedimensional, vertically hydrostatic, free surface, turbulent averaged equations of motion for a variable-density fluid. Dynamicallycoupled transport equations for turbulent kinetic energy, turbulent length scale, salinity and temperature are also solved. The EFDC

model allows for drying and wetting in shallow areas by a mass conservation scheme. The physics of the EFDC model and many

aspects of the computational scheme are equivalent to the widely used Blumberg-Mellor model and U. S. Army Corps of

Engineers'Chesapeake Bay model. EFDC's role in the TMDL Toolbox will be to provide necessary hydrodynamic inputs to WASP,

the advanced receiving water quality model.

EFDC Preprocessor

In order to facilitate the setup and application of EFDC, a preprocessor is being developed. The preprocessor will be composed of

two major components: the Curvilinear Grid Generator and the EFDC Model Interface. Together these components will enable users

to generate curvilinear-orthogonal grids, simulate aquatic systems in 1, 2, or 3-dimensions, link 2-D grids to 1-D grids, quickly and

easily set and change critical modeling parameters, and make use of watershed loading model results and monitoring data for

boundary conditions.

The Curvilinear Grid Generator will enable a user to generate curvilinear-orthogonal grids that are required for the numerical model.

It will significantly decrease the repetitive effort typically required through manual grid generation methods. Grid generation will be

conducted interactively and intuitively through the interface and associated controls. Key features of the tool will include:

GIS interface

Model domain designation through user control point designation

Automatic insertion of grid boundary points based on control point designation

Automatic curvilinear-orthogonal grid generation

Model grid conversion to GIS shape file format

Cell mapping between EFDC and WASP

Once a grid has been generated, it's necessary to set and calibrate pertinent modeling parameters. The EFDC interface will simplify the setup and application of EFDC through

a user-friendly graphical interface and associated windows. It will support input of EFDC model run control and model parameter designation, and it will link directly to boundary

condition/source data, e.g. watershed model output and point source contributions. Key features of the tool will include:

http://www.epa.gov/athens/wwqtsc/html/efdc.html

Environmental Fluid Dynamics Code (EFDC) Page | Ecosystems Research | US EPA http://www.epa.gov/athens/wwqtsc/html/efdc.html

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Database-oriented interface

Visual linkage to the model grid

Visual linkage to point and nonpoint source inputs

New model parameter addition and accommodation

Direct linkage to WRDB for boundary condition designation/generation

EFDC Model Information

Current Version 1.0

Release Date July 9, 2002

Operating System Windows 95/98/ME/2000/XP

Intended Audience Environmental Engineers/Scientists, Regulatory Agencies

Key Words hydrodynamics, temperature, salinity, stratification NPS related,

NPDES, point source(s), surface water, test/analysis, TMDL related

Media Lakes, Rivers, Estuaries

Pollutant Types hydrodynamic transport, links with Water Quality Analysis

Simulation Program (WASP7)

File Type/Priority Filename/Format/Size File Description

Install/Required EFDC-HYDRO.EXE (EXE) --

Self Extracting Zip File

1 MB

This file contains the EFDC

hydrodynamic model. Does not include

the EFDC water quality components.

Includes a 3-D example of rectangular

cross section river. User is encouraged

to download model documentation.

Optional EFDC Manual --

Zip File

538KB

This file contains the EFDC-Hydro

Manual PDF in zip format.

Optional EFDC Fact Sheet -- (PDF, 2

pp., 764KB, about PDF)

This file contains a Fact Sheet about the

EFDC Modeling System in PDF Format.

File Download Information

Technical Support Center fact sheet (PDF, 2 pp., 733 KB, about PDF)

TMDL fact sheet (PDF, 2 pp., 697 KB, about PDF)

Environmental Fluid Dynamics Code (EFDC) Page | Ecosystems Research | US EPA http://www.epa.gov/athens/wwqtsc/html/efdc.html

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WCMS

Last updated on Tuesday, November 01, 2011

Environmental Fluid Dynamics Code (EFDC) Page | Ecosystems Research | US EPA http://www.epa.gov/athens/wwqtsc/html/efdc.html

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