Importing Multiple Grids into EFDC_Explorer

EFDC_Explorer allows the option of importing of multiple grids and joining them together within the Grid Generator module.

While it is possible to join the separate domains using external grid generators one by one, this only works if they are all in the same i, j domain. For example if a user has several domains they must first load one domain then paste this and add more one at a time. In the end the user will have only one grid which they can then import into EFDC Explorer.

If all the grid sub domains are not in the same i, j domain then the sub-domains will have to be brought in separately. This must be done manually by the user. However, EE helps with this process by allowing the user to set the N-S or E-W connection. Once the model is saved EE will generate a MAPPGNS.INP or MAPPGEW.INP file or both of them depending on which type of connectors established.

Using the example grid files titled Part01.grd and Part02.grd the user should follow the steps as shown below:

1. Open EE
2. Select Generate New Model button on main menu as shown in Figure 1.
3. Select grid type to import then browse to Part01.grd then check on Check for Disconnected Sub-Domains and Load Additional Sub-Domain GRD Files as shown in Figure 2.

Figure 1. EE main form.

Figure 2. Generate EFDC Model form.

The user should then selected Generate button whereon they will be prompted for the other sub-grids, in this case Part02.grd as shown in Figure 3.

After selecting Part02.grd to open, EE will inform the user number of sub-domain grid and number of cells of each sub-domain gird as shown in Figure 4.

Figure 3. Load the second sub-domain grid.

Figure 4. Number of sub-domain grids loaded.

Figure 5. Sub-Domain grids viewed in EE.

To connect two sub-domains, the user proceeds to ViewPlan | Fixed Parameters | Cell Connections tool. Alternatively, select ViewPlan | Bottom Elevation viewing option and Enable Edit and N-S / E-W check boxes as shown in Figure 6. The user should right mouse click on a cell they wish to connect to another grid. This will provide a pop-up with the option New Cells Connection. At this stage, the user can select one of three options as shown in Figure 7.

Figure 6. Sub-Domain grids in ViewPlan.

Figure 7. New cell connection options.

For example, select New Single Cell Connection then LMC to select the adjoining cell on the other grid. A N-S connector will then be created as shown in Figure 8. 

Two other options involve using polylines to define the cells on each grid that are to be connected. The New Group Connection across 2 polyines lets the user draw a polyline (LMC to start, RMC to end) on each grid. When the second polyline is completed EE will prompt the user for setting N-S, E-W or both kinds of connectors to be assigned. The New Group Connection across an existing polyines files allows the user to use predefined polylines, which have been created saved by the user, to be loaded to set the connectors. 

Figure 8. N-S connector established.