Steps To Set up a Sediment Bed Model

The following provides the keys steps to carry out when building a sediment bed model using either the original EFDC sediment sub-model or the SEDZLJ sediment sub-model. 

  1. Click the Modules item in the menu in the Model Control form and check on one of the boxes (Original) Cohesive Sediments, (Original) Non-Cohesive Sediments,  or SEDZLJ Sediments then click the OK button. (Figure 1).
  2. The Sediment option will be added to Modules. RMC on the Sediment item and select Settings. The Sediment and Sediment Bed Properties Settings  form is displayed as shown in Figure 2.
  3. Define the number of sediment bed layers, cohesive and non-cohesive sediments as shown in Major Settings of EFDC Sediment Model (it is important to do this first to avoid losing data).
  4. Set the options in the General tab for the Primary Computational Options and the Bed Shear Calculation Options.
  5. In the Cohesives tab the user should enter the appropriate values for the relative parameters as well as defining the minimum and maximum values of Cohesive Fluids Concentration as shown in Figure 2.
  6. In the Non-Cohesive Suspended tab the user should define the Equilibrium Concentration Option and enter the appropriate values for the relative parameters and non-cohesive layers.
  7. In the Non-cohesive Bed tab the user should click on Initialize Constants button and enter the number for the approach desired e.g. enter "1" for the Van Rijn approach.
  8. In the Morphology & Consolidation tab the user should select the Bed Morphology Options: check-box, off is no bed change, on is allow bed changes. The user should also set the Max Layer Thickness and Constant Porosity to be the same values as those in the input sediment file (refer to Appendix B - Data Formats for the DSM format of the file).
  9. In the Initial Conditions tab: select the Sediment Initial Condition Options. Then click Assign Bed IC button, there are 2 options to initialize bed layers: uniform bed and use initial data file.
  10. Initialize the sediment bed from the file, browse for the input sediment file
  11. Check Use sediment cores with grain size
  12. Define the maximum grain size for each size class relatively to cohesive and non-cohesive layers as displayed in the red frame in Figure 3.

If the required information has been entered then the Apply button is visible. After clicking on Apply, the sediment bed will be initialized.

Figure 1.  Activate sediment modules.

Figure 2.  Sediment Bed Model: Cohesives Tab.

Figure 3.  Initialization of Sediment Beds.