U.S. ARMY CORPS OF ENGINEERS – NEW ORLEANS DISTRICT

7400 LEAKE AVENUE, NEW ORLEANS, LA 70118

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http://www.facebook.com/usacenola

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LOUISIANA COASTAL PROTECTION AND RESTORATION AUTHORITY

450 LAUREL STREET, BATON ROUGE, LA 70808

http://coastal.louisiana.gov

Mississippi River Hydrodynamic 

and Delta Management Study

Multi-Dimensional Modeling

Team Leaders: Ehab Meselhe, Water Institute of the Gulf (CPRA), and Gary Brown, Engineer Research and 

Development Center (USACE) 

Team Participants: USACE New Orleans District, USACE Engineer Research and Development Center, University 

of New Orleans, Coastal Protection and Restoration Authority of Louisiana, the Water Institute of the Gulf

Purpose: Apply a suite of numerical models (FLOW-3D, Delft-3D, FVCOM, ADH/SEDLIB) that can accurately 

simulate the pertinent physical processes in the river and adjacent basins. The output from these models contributes 

to the engineering, design, operation, and management of proposed river diversions and enhances our 

understanding of the potential influence that diversions will have on river and wetland morphology.

Objectives:

 Develop tools that can reflect existing and future conditions of:

 Hydrodynamics and bed shear stress

 Sediment transport and fate

 Sediment sorting and armoring

 Sediment diversion dynamics

 Morphologic change in the river and receiving basins

 Salinity effects (stratification, sediment flocculation)

 Focus on sub-sections of the Lower Mississippi River (LMR), with a focus on event and annual time scale 

simulations, as well as specific stage/flow conditions, such as peak or low flow. 

 The modeling tools must be capable of representing both the existing conditions of the river (to establish the 

relative significance of various governing physical processes) as well as the local and system-wide changes 

due to proposed restoration strategies.

 Use inter-model comparisons to enhance confidence in the conclusions drawn from the collective model 

results, and to minimize risks from decisions made based on these results.

Challenges:

 Accounting for Local Subsidence and Sea Level Rise

 Wide range of temporal and spatial scales of relevant physical processes

 Complex water-sediment dynamics in the LMR

Status:

 Model computational grids have been constructed.

 Calibration and validation using observational data is in progress.

 Model refinement and project modeling runs will continue through FY14.

Anyone seeking additional information on the MRHDM Study can visit the LCA program website at www.lca.gov, at

the New Orleans District LCA website at 

www.mvn.usace.army.mil/Missions/Environmental/LouisianaCoastalArea.aspx, or the CPRA website at 

http://coastal.louisiana.gov

October 2013
U.S. ARMY CORPS OF ENGINEERS – NEW ORLEANS DISTRICT

7400 LEAKE AVENUE, NEW ORLEANS, LA 70118

Visit the following links to follow us on Facebook, Twitter and Flickr:

http://www.facebook.com/usacenola

http://twitter.com/teamneworleans

http://www.flickr.com/photos/teamneworleans

LOUISIANA COASTAL PROTECTION AND RESTORATION AUTHORITY

450 LAUREL STREET, BATON ROUGE, LA 70808

http://coastal.louisiana.gov

Mississippi River Hydrodynamic 

and Delta Management Study

Multi-Dimensional Modeling

Fig. 1 FVCOM-3D model output 

showing salinity gradients in the 

lower river and bird’s foot delta.

The focus of this model is on 

hydrodynamic, sediment and salinity 

processes in the reach from Empire to 

the Gulf. The model domain integrates 

the lowermost river with the bird’s foot 

delta and receiving basins. This model 

is designed to track the upstream 

movement of the salt wedge and to 

simulate the impacts of the multiple 

existing and proposed diversions on 

salt wedge dynamics.

Fig. 2 FLOW-3D Model Domain and 

location of the proposed Mid Barataria 

and Mid Breton Sound Diversions. 

This model focuses on high-resolution 

sediment and water details around 

selected diversion intakes. It is used to 

optimize the location of intake structures 

and optimize diversion channel alignment 

to maximize the benefits (sediment 

capture and delivery) of proposed 

diversions. It also produces watersediment diversion coefficients that are 

used as input for the regional 1-D HEC6-T 

model.