EFDC+ Explorer 12 User Guide

Owned by Kester Scandrett
Last updated: 09 Aug, 2024
6 min read

EE10 implements a significant enhancement in the pre- and post-processing capabilities of the EFDC_Explorer Modeling System. Along with new features and capabilities, EE10 presents an improved system of organizing the model settings and the viewing option that will be familiar to users acquainted with GIS and similar software tools.

This user guide is divided into three sections. The first section outlines the distinctive approach in the Navigating EFDC+ Explorer section. This briefly describes the various menus and forms that are used in EE10, the distinctive approaches to using them, and provides links to more detailed descriptions of each item.

The second section, Working with Models, describes the overall process the user should undertake to load, build, save, run, and visualize models.

Subsequent sections provide an in-depth explanation of each of the Model Control Form, plan view of the model (2DH View), slice views (2DV View), Time Series, Longitudinal Profiles Plots, Vertical Profiles. At the lower level the operation of the Model Control Form is similar to previous versions of the EE8 series, although navigating to the forms is quite different.

A separate How-To Guide for EE10 provides step-by-step guidance on how to set up, run, and visualize a variety of different models.

Please reference this document as follows: 

DSI LLC. 2023. EFDC+ Theory, Version 11.8. Published by DSI LLC, Edmonds, WA. Available at:

https://www.eemodelingsystem.com/wp-content/Download/Documentation/EFDC_Theory_Document_Ver_11.pdf

What's New in EEMS 12.1?

With the release of EEMS 12.1 a number of enhancements have been made to the EFDC+ code as described below. Improvements and bug fixes were also made to EFDC+ Explorer and Grid+.

  • COARE 3.6 Integration: COARE is one of the most frequently used algorithms in the air-sea interaction community to predict surface temperatures. It is designed to give estimates of the turbulent fluxes of sensible and latent heat and the stress from measurements of bulk variables such as water temperature, air pressure, and specific humidity. With the release of EEMS 12.1, the Environmental Fluid Dynamics Code Plus (EFDC+) will allow users to simulate these fluxes by incorporating the COARE subroutines. You can learn more about the implementation of this feature in our introductory blog post. In this more recent blog post, we have also demonstrated that the algorithm can be applied in freshwater bodies such as Lake Mendota.
  • Vertical Layering Enhancements: A new vertical layering option following the Sigma-Zed (SGZ) approach has recently been added to EEMS. The new SGZ scheme allows the user to specify layer thickness in meters from the water surface. Itoffers significant flexibility in configuring the vertical layering system, complementing the existing options, including the original Sigma Stretch (SIG) and the current Sigma-Zed (SGZ). Learn more about these changes by reviewing this blog post or reading the Knowledge Base.
  • Volatilization Option: When simulating chemical fate and transport, volatile chemicals at the air-water interface frequently off-gas from the water into the atmosphere. The Chemical Fate module in EEMS is designed to work primarily in conjunction with the Sediment module, as the toxic substances sorb to sediments. In cases where sediment data is sparse or missing altogether, using a dye class as a proxy for the dissolved chemicals is recommended. To help users more accurately simulate this case, a volatilization component has been added to the dye proxy. To learn more, read this blog post or the EFDC+ Theory Document.
  • 3 Time Level Scheme Updates: A number of improvements have been made to the 3 Time Level (3TL) computational scheme. This numerical solution option is often more stable and faster than the 2 Time Level (2TL) scheme since it allows a larger computational time step. However, the 3TL scheme was not fully implemented in the original EFDC from Hamrick. DSI has refactored the code for the application of parallel computing using OMP-MPI. DSI has also fixed several bugs in the code so that 3TL has now become our favored solution option for hydrodynamic models.
  • NetCDF Updates: EFDC+ has recently been integrated into studies as part of the Delft-Flood forecasting and Early Warning System (FEWS) platform. Delft-FEWS is open software using a modular framework to link big data to a local area or from other modeling systems. In this study, EFDC+ was required as one of the modules, and the NetCDF capabilities were required to be updated to the latest convention to allow seamless integration. Some of the improvements for EEMS 12.1 include:
    • Upgraded NetCDF CF Conventions 1.4 to 1.11
    • Upgraded to UGRID 1.0 Conventions
    • Fixed standard names and units according to NetCDF CF Conventions 1.8 checker

What's New in EEMS 12.0?

The major advance in EEMS 12 is the addition of the GOTM (General Ocean Turbulence Model) to EFDC+ and EE. In addition, algae vertical migration is now simulated by EFDC and configured in EE.  The major change to EE is the new capability of handling the Geographic coordinate system. Other changes include:

  • Macrophyte Hydrodynamic Feedback 
  • 3TL timestep adjustment, MPI for 3TL 
  • Move QSER inflows 
  • Improved wind-generated wave approach
  • Buoyancy with potential temperatures 
  • Navigation locks 
  • Improved vegetation drag approach 
  • Jet-Plume with W/R flow for MPI 

What's New in EEMS11.4 to 11.7?

The long-term stable release of EEMS contained a number of new features. Some of the main ones included: 

What's New in EEMS11.3?

DSI has developed a new generation grid-building tool called Grid+, which is available with the release of EEMS11.3. Grid+ replaces our previous grid generator, CVLGrid, which is still available in EEMS10.3. User guidance for Grid+ is available here. The new EEMS also contains the following enhancements:

  • Macrophyte and periphyton growth can now move between layers and be visualized in EE. 
  • Macrohydro options allow for the impact of macrophyte growth on hydrodynamics
  • Fast settling of sediments has been implemented and integrated into the ChemFate module
  • ChemFate partitioning options have been supplemented
  • NetCDF now writes to a separate file for the drifters module 

What's New in EEMS11.2?

One change in EEMS11.2 was changing the name of the tool from EFDC_Explorer to EFDC+ Explorer. A number of bug fixes were made to EFDC+ and enhancements in EE included:

  • Adding time steps for NetCDF output frequency
  • Ability to display the average of a group of cells for time series 

What's New in EEMS11.1?

EEMS11.1 implements a number of enhancements. The ability to export the EFDC+ output files in the latest NetCDF UGRID format provides considerable efficiency gains. This approach has been used in the Lake Washington Real-time model for some time and is now being made available to users of EEMS.  At the request of several clients, we have upgraded EFDC+ so that it can now write the hydrolink file required by the WASP8 water quality model. These enhancements and several others are outlined on this page, and briefly summarized below with links to the relevant pages in this User's Guide. Changes have been made to both EE and EFDC+ unless otherwise noted:

What's New in EEMS10.3?

Enhancements to EEMS10.3 provide powerful new sediment transport capabilities in the propwash module, as well as a significant upgrade to the aquatic biota capabilities. These enhancements and several others are outlined in this page, and briefly summarized below with links to the relevant pages in this User's Guide. Changes have been made to bother EE and EFDC+ unless otherwise noted:

What's New in EEMS10.2?

EEMS10.2 provides a number of significant enhancements to this modeling system. These are briefly summarized below with links to the relevant pages in this User's Guide. Changes have been made to bother EE and EFDC+ unless otherwise noted:

What's New in EE10?

It is unrealistic to try to list all of the “differences” between EE8.5 and EE10 because EE10 is a wholly rewritten interface in a modern programming language.  However, some of the more significant changes include:

  1. Written in the latest .Net framework, mostly in C#.  We anticipate this more modern tool has the prospect of decades of future development and maintenance. The old EE (all versions before 10.0) were written in VB6, which are no longer well-supported by Microsoft. 
  2. A completely different user interface that is flexible and powerful to accommodate the existing EFDC+ capabilities but can be readily updated for all of the upcoming changes to EFDC+.
  3. A Model Control window to create, edit, report and/or view EFDC+ models (Model Control).
  4. A model results harmonic analysis tool.
  5. Load multiple models simultaneously with temporally linked 2D views and animations.
  6. View multiple time series and 2D plots simultaneously.
  7. 2D plan view now has true layer controls for viewing multiple constituents, labels, background imagery, data, and much more.
  8. Robust set of model cell selection and editing tools.
  9. HTML-based user run logs.
  10. HTML-based complete model run summaries by feature/module or for the entire model.
  11. Links to web-based data sources for water levels/harmonics.
  12. A geo-referencing tool that allows for image rotation and distortion control.
  13. EE assisted model nesting tool 
  14. Save and restore model(s) layouts for Windows and Windows settings.

What's New in EFDC+ for EE10?

EE10 also includes a number of significant improvements and new features in the EFDC+ code. Some of the features in version 10 compared to version 8.4 include:

Use of Spatially and Temporary Varying Fields

EEMS10 now has the ability to simulate spatially and temporally varying fields, such as wind or barometric pressure fields. EFDC+ can receive time varying forcings within its computational domain from external sources in the form of ASCII or binary files. These fields can be configured for:

  •   Topographic data (e.g., dredging/dumping, land erosion/reclamation, subsidence)
  •   Roughness (e.g., seasonal roughness)
  •   Vegetation field
  •   Seepage/groundwater flow
  •   Wind field (e.g., cyclone)
  •   Barometric pressure field (e.g., cyclone)
  •   Rainfall
  •   Evaporation
  •   Wind shelter field
  •   Sun shading field
  •   Ice thickness
  •   SEDZLJ erosion rate multiplier
  •   SEDZLJ erosion rate exponent

Sediment Transport Updates

  • Improved sediment bed initialization with more QC checking.
  • User-defined cell-by-cell activation/deactivation of sediment transport for both SEDZLJ and Original sediment module.
  • Updates to SEDZLJ:
    • Added equation-based erosion rate calculations (E = A*tau^N)
    • User-specified maximum erosion rate by class and layer
    • Added cell by cell sediment bed characteristics independent of SEDFLUME cores
    • Improved bed shear calculation approach (Parker, 2004)

User Defined Dye Classes

The number of dye classes is now unlimited, with each class able to have a unique set of properties including:

  • 0th order decay or growth
  • 1st order decay that is optionally temperature-dependent
  • Settling velocity
  • Age of water

Vertical Masks

  • Face blocking can be applied to block vertical layers. The user defines the height from the top (draft) and bottom (sill) of the water column for the blocking layer
  • Layers may be configured as fixed or floating and can be attached to an anchor. 
  • This new capability allows the model to simulate partially blocked depths due to floating objects (e.g. ships and bridges), baffles, submerged weirs, and/or other submerged features.  The blockages influence flow, constituent transport, particle tracking, and wave action. 

Other Enhancements

  • Dry and wet atmospheric deposition of toxics
  • Restructured water column transport and vertical diffusion to reduce computational times.
  • Spatially varying background vertical diffusivity (AVO).
  • The reported flows in the EE linkage file EE_BC.OUT now contains integrated flows for better mass balance calculations in EE.
  • Other code changes to improve model performance and accuracy.