When building an EFDC model, we need a bottom elevation (or bathymetric data file) assigned to the model grid. However, we just have cross-section files in the model domain. So, how do we create a bottom elevation file for the model grid by using this cross-section?
This page will provide steps to do this.
As described in the ..., Grid+ allows the creation of data points from the grid cells that already have the grid's elevation. So, we have to take data point values from cross-sections and then assign them to grid cells.
The grid used for generating the bottom elevation file does not have to be the same as your model grid. The density of points in the bottom elevation file will be based on the grid's resolution.
- Load the cross-sections file, and after that, generate a grid to cover the cross-section, as shown in Figure 1. To show the color ramp of the cross-section, press Alt+C, then set Min. and Max. values.
- Draw a polyline to cover grid cells with cross-section by selecting Add a new polyline button from the toolbar, as shown in Figure 2.
- Press the S key from the keyboard (selection mode), select the overlay layer in Layer Control panel, then click on the polyline, then it will be highlighted, as shown in Figure 3.
- Next,
Figure 1 Load cross-sections with a generated grid.
Figure 2 Draw polyline to select grid cells with cross-section.
Figure 3 Select the interpolate grid elevation option.
Figure 4 A Show bottom elevation of cells.
Figure 5 Modify Selection form.