SMS:Dredging Coverage

The Dredging Operations and Environmental Research (DOER)group in the U.S. Army Corps of Engineers has sponsored a set of dredging tools in the SMS interface. These tools simplify the process of creating numerical simulations of a dredging process. The toolbox actually includes several dredging models of varying complexity. The SMS also includes interfaces for setting up individual simulations using each of these models.

Using this toolbox, an engineer may evaluate conditions at a dredging site, a placement site or both. Equipment used in the project may be selected from a list of existing vessels or defined locally. A typical project consists of the following steps

Flow of Control at Dredge Location

1. Define a new Dredging Simulation. You do this by right clicking in the Project Explorer and selecting "New → Dredging Simulation". This will create a "Dredge" entry in the Project Explorer as well as a new simulation. You will now add specific dredging processes to the simulation.
2. Define the sediment (material types) and Sediment Parameters. Right clicking on the "Dredge" entry of the project explorer allows access to these parameters.
3. Define a Dredging Coverage for each dredge operating in the project area. In that coverage, specify the equipment (coverage properties), the zone that equipment will work in (polygons with material types) and the paths (or typical paths) it will follow. Drag the dredging coverages into the simulation created in the previous step.
4. Generate PTM sources at the dredging site using specified losses or from results of the dredge source model by right clicking on the simulation and selecting "Generate PTM Sources ...".
5. Run PTM to see where sediment migrates and deposits.

Flow of Control at Placement Location

1. Set up Dredge Location information as specified above.
2. Define a Fate domain as the placement zone. Drag this grid into the dredging simulation.
3. Generate MPFate loads or MKPlacement locations from results of the simulation by right clicking on the simulation and selecting "Generate MPFate ..." or "Generate MKPlacements".
4. If desired, run MPFate in the placement zone to evaluate filling of the placement zone.
5. If desired, run STFate at specific placements in the placement zone to evaluate water quality and produce PTM sources.
6. If desired, run PTM to see where sediment from the placement zone migrates and settles.

Flow of Control for Both Dredge and Placement Locations

1. Set up Dredge Location information as specified above.
2. Set up Placement Location information and run STFate as specified above.
3. Run PTM to see where combined sediments from both the dredge and placement zones migrate and settle.

Additional simulations may be created by right clicking on the "Simulations" item in the project explorer. These may be used to evaluate other combinations or alternatives. Dredging coverages may be in multiple simulations.

Models included in the Dredging Toolbox

• Dredge Source Model – calculates the sediment sources generated at the dredge site. These sources can be input to PTM.
• STFate – models the descent and collapse of a sediment cloud released from a barge or hopper. Outputs concentrations at various depths throughout the process, deposition on the bottom and particle sources stripped out of the cloud. These stripped quantities can be input to PTM.
• MPFate – models the combined effect of multiple STFate placements. Combines the short term placement operation with avalanching and consolidation to evaluate the net effects on the placement zone.
• MKPlacement – computes placement locations over a placement zone. This is one part of MPFate.
• PTM – tracks sediment material moving through modeling domain. Simulates motion of this material as individual particles.
• LTFate – model built on the EFDC/SED-ZLJ engine to simulate long term bed transport. Could be applied over placement zone results from MPFate to simulate later movement of materials away from initial placement.