We are pleased to share with you the details of our latest updates to the EFDC_Explorer Modeling System.

Full Features List

EE8.3 New Features

The EFDC_Explorer/EFDC+ has now been enhanced to correctly handle toxics when using the SEDZLJ sub-model. This includes proper working of the diffusion parameters, as well as mass balance in the water column and sediment bed. Previously the SEDZLJ sub-model in EFDC+ only handled sediments. SEDZLJ is the US Army Engineering Research and Development Center recommended model for hydrodynamic and sediment transport modeling.
The SGZ sub-model has been modified to allow parts of the model domain to be reduced to one vertical layer. Previously SGZ required a minimum of two layers for all model simulations. Being able have one vertical layer is useful in situations when there are 1-D rivers feeding into a many layered reservoir or lake.
EFDC+ has been modified to only write out active vertical layers to the linkage files, thereby reducing the output file size significantly. EE has also been updated to read the new file format, as well as continuing to load the legacy file formats.
This updated EFDC+ code revises and improves the ice sub-model. This is especially applicable for very thin layers of ice which are now handled more realistically in this update.

EE8.2 New Features

Since 2009, EFDC+ (formally EFDC_DSI) has had the SEDZLJ sediment transport sub-model functional. However, this previous implementation did not have any EE pre-processing support and limited post-processing. Beginning with 8.1 and now fully implemented in 8.2, EE now fully supports the pre- and post-processing of SEDZLJ sediment transport models. The new SEDZLJ approach has been developed by Sandia National Laboratories and accounts for multiple sediment size classes, has a unified treatment of suspended load and bedload, and appropriately replicates bed armoring. The resulting flow, transport, and sediment dynamics model is an improvement on previous models because it may directly incorporate site-specific data, while maintaining a physically consistent, unified treatment of bedload and suspended load. SEDZLJ sediment transport models can now be built, edited and model results analyzed using the EE8.2 GUI, which also provides many QC helps and checks.
EE and EFDC+ now fully incorporates the pre- and post-processing of the Marine Hydrokinetic (MHK) module for simulation of placement and potential effects of installing and operating turbines and wave energy converters in rivers, tidal channels, ocean currents, and other waterbodies. The updates to the EFDC code come from SNL-EFDC, the Sandia National Laboratories modified version. The EE8.2 GUI can be used to build and edit an MHK model, and the user can view the location and the impacts of the devices in 2D and 3D.
The EE and EFDC+ code have been upgraded to allow export of netCDF-CF formatted data for one or multiple constituents directly from EFDC+. This work has been performed with the goal of providing the user with EFDC+ output that can be directly read and displayed on web servers and real-time modeling applications. The Network Common Data Form (netCDF) software is a common data access method for a variety of data types that encompass single-point observations, time series, regularly-spaced grids, and satellite or radar images.
A new temperature sub-model has been added to EFDC+. This new feature, titled “Full Heat Balance with Variable Extinction Coefficient”, now adds temporally and spatially varying light extinction factors to the “Full Heat Balance” sub-model. The extinction factors are determined on a cell by cell basis for each time step based on TSS, and if the water quality model is active, for POM, DOM and Chlorophyll-a. Furthermore, a number of changes have been made to the GUI to ensure a more streamlined user interface and intuitive modeling experience.
EFDC+ has been modified to include the effects of horizontal atmospheric pressure gradients on the water surface elevations. This new capability allows EFDC+ to address these gradients in large coastal and inland systems. This feature is only available when two or more atmospheric pressure time series are specified, otherwise the horizontal gradients are always zero.
Other enhancements in EE8.2 include: Station Weighting Assignment improvements for Wind/Ice/ASER files; Drifter Count Tool - Count drifters in a user specified area; Improvement to 3D display options; Simplified Numerical Options; as well as many minor modifications and bug fixes.

EE8.1 New Features

A new feature in EE8.1 is the ability to display a list of cells selected for times series extraction. A family of time series curves of the same parameter can quickly be displayed in EE. For all parameters except for the water depth derived parameters, each time the user selects a new cell the Cell Selection List is updated with the I, J and K of that cell and the cell location is shown on the model domain. A number is shown next to each cell selected which corresponds to the list. There is no limit to the number of time series can be shown at once. The user may manually adjust the I, J and K value in the list, as well as turn on or off a cell. The user may save and reload a list of time series location for use at a later time.

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EE8.1 provides the option of offline licenses with USB dongles. These USB dongles are sent to our users so that they no longer need to connect to the internet to activate. Please contact us for information on this premium licensing feature.

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An alternative to the standard sediment transport approach is the the start-of-the-art SEDZLJ submodel. The SEDZLJ Sediment sub-model is implemented in EFDC_Explorer for display of SEDZLJ input data and results. However, at this time, the user cannot create or edit input data.

If the user has created a valid SEDZLJ model then the option for SEDZLJ may be displayed. The options available include display of the Core Zone, Erosion Rate, Deposition Rate, Net Dep/Erosion Rate, Bedload Concetration, d50 (Active Layer).

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EE8.1 has been updated to provide a simplified user experience for formatting lines for time series plotting. The user may now set the thickness, color and style with a number of drop-down menus.

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EE8.0 New Features

EFDC_Explorer8 now implements DSI’s improved version of the EFDC code, Sigma Zed, as part of efdc+. DSI has developed this version to deal with the pressure gradient errors that occur in simulations that have steep changes in bed elevation. This new version of the code is called the Sigma Zed (EFDC_SGZ) code. This contrasts with the conventional sigma stretch version (SIG) of the EFDC code which uses a sigma coordinate transformation in the vertical direction and uses the same number of layers for all cells in the domain. In the EFDC_SGZ model, the vertical layering scheme has been modified to allow for the number of layers to vary over the model domain. Each cell can use a different number of layers, though the number of layers for each cell is constant in time.

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EE8 now uses array pointers to enable the loading of much larger numbers of drifters than was available previously. Though EFDC has no practical limit to the number of drifters to be simulated, there can be memory issues with displaying large number of particles depending on the hardware specifications. This problem has now been overcome in the latest version of EE, which allows hundreds of thousands of drifters to be displayed at one time.
EE8 can now be used to simply and quickly setup up hydraulic structures such as culverts, weirs, sluice gates, and orifices. efdc+ can simulate these structures define by the user. EE maintains the previous option of defining a flow series for each hydraulic structure. With this new functionality EE helps the user visualize hydraulic structures and then build the equations governing the behavior of these structures in the EFDC model.
EE8 and efdc+ the user can connect disconnected sub-domains via East – West connectors, providing significantly more flexibility when connecting multiple disconnected subdomains. The EFDC_DSI/EFDC_Explorer modeling system had the ability to connect disconnected subdomains with North-South connectors since release of EE7. Now with East-West as well as North-South connectors the user can build considerably more complex models.
EE8 uses a new and improved licensing system that will allow offline licenses with dongles (coming soon) as well as license rentals. The new system will also provide increased stability and ease of user for our licensed users.
The release of EE8 also brings new licensing options for the user. We are now offering subscription licenses in 3-month, 6-month, and 1-year terms. Of course, EE8 will still be available as a perpetual license as well.

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