Sediment Transport

Sediment processes are important to scientists and engineers when addressing environmental issues such as sedimentation, scour and deposition, submerged aquatic vegetation (SAV), eutrophication, and toxic contaminant transport. Two options available for simulating the bed/water interaction are the original approach used in the EPA version of EFDC and the SEDZLJ approach, which uses SEDFlume data. By using the SEDZLJ approach, EFDC+ provides unparalleled power and versatility in simulating these multifaceted environmental issues.

SEDZLJ Sediment Transport Model

SEDZLJ is regarded as one of the most advanced sediment transport models in the world. Developed by Sandia National Laboratories (SNL), SEDZLJ uses sediment flume data to determine erosion rates and critical shear stresses.  Tested extensively in the   EFDC+ provides significant enhancements and bug fixes compared to the EFDC_SNL version of this valuable tool.  Major enhancements include the multi-threading of SEDZLJ for faster runtimes and the extension of the SEDZLJ sediment transport code for toxics transport.

Total suspended sediment and sediment bed in SEDZLJ morphological model.

Cohesive and/or Non-Cohesive Sediment Classes

EFDC+ can simulate the transport and fate of any number of size classes of cohesive and non-cohesive sediment, non-cohesive bedload, and bed scour, deposition, and resuspension.  This flexibility allows you to address systems sediment transport issues ranging from simple to complex.

Bed Processes

Using EFDC+, you can represent the sediment bed by a single layer or multiple layers. The multiple-bed layer option provides the ability to establish a time-since-deposition position versus vertical position in the bed relationship. You can also simulate bed armoring, providing important insights into the nature of erosion and deposition in your system.

Non-Cohesive Bedload Transport

EFDC+ has extended bedload transport to the SEDZLJ module, with updates for both approaches to ensure mass balance.

Bed Morphology/Feedback to Hydrodynamics

EFDC+ supports bed morphology simulation with elevation changes in the water column/sediment bed interface. These are incorporated into the hydrodynamic continuity equation, giving you seamless morphodynamic simulations without the need to link to other models.