Modify Model Grid

Owned by Duy Pham
Last updated: 27 Apr, 2021 by Bui Bich Thuy (Deactivated)

The editing of the model grid through 2DH View is mainly done in the Layer Control window. The user first has to click on the pen icon  to enable modifying, then RMC on the cells to directly edit or RMC on the layer to see additional options.

1. Model Grid Layer:

RMC on Model Grid show options to modify the I and J indices of the model such as rotate, flip, transpose (Figure 1). These I-J functions are used during the grid generation- importing process to correct any model I-J orientation issues. Additionally, RMC on the model cell allows us to deactivate that cell or rotate grid cell corners for that cell (Figure 2). This function applies a rotation to the cell rotation angles, it does not rotate the actual cell. If using the CORNERS.INP file, just applies a user-specified rotation to the cell rotation matrix. In EFDC the cell’s rotation matrix is used for velocity plots and interaction with the wind field.

Figure 1. RMC on Model Grid layer to show I-J functions.


Figure 2. With Model Grid Layer selected, RMC on a cell to edit.


On corner cells, the added options of turning the border cell into a triangular cell are available by RMC on the cell (Figure 3), then select Change to Triangular Cells option. RMC on the cell again to show the option of changing it back to quad-cell by selecting the option Change to Quadrangular Cells.


Figure 3. Triangular cell option in Model Grid layer (1).


It is able to select multiple cells to apply this option at the same time by using Selection Tool first, then use this feature as applying for a cell as described above. (See Figure 4).

To use this feature for all corner cells of an entire grid domain, from keyboard press Alt + T, a message form of Triangular cells on the border pop up as shown in Figure 5. Select Yes to convert all corner cells to triangular cells.



Figure 4. Triangular cell option in Model Grid layer (2).


Figure 5. Triangular cell option in Model Grid layer (3).


2. Grid Connection Layer:

Add N-S or E-W grid connectors for different grid domains. Select Grid Connections layer in Layer Control then RMC on a cell from one grid which is to be connected to another grid, and select Add N-S Connection (or Add E-W Connection), then LMC to set the second connection point (see Figure 6).

Figure 6. Add new grid connection.