This article will detail how to create a grid and will include an example.
A 2D computational grid needs to be created, as this will specify the locations and resolutions of the 2D cells, which will be considered in the interpolation process for the generation of the digital terrain data file.
The modelling software is able to generate different types of grids, illustrated in the next figure:
Figure 1 – Different types of grids generated by OpenFlows FLOOD
As an example, we will create a simple constant-spaced grid (similar to the one used on the DTM generation for the Graz workspace):
This will open the “Constant Spaced Grid Tool” docked on the right of the main area. Your window should look like the one shown in the next figure.
Figure 2 – Create Constant Spaced Grid
Please use the parameters detailed in the next figure:
Geographic Coordinates (the default)
Type of the coordinates to use. Options are geographic, UTM and metric (local) coordinates.
X coordinate of the lower left corner.
Y coordinate of the lower left corner.
Nº of columns of the grid
Nº of rows of the grid
Size of the grid cells along the X axis. Given in units of the coordinate system (in this case º).
Size of the grid cells along the Y axis. Given in units of the coordinate system (in this case º).
Rotation of the grid.
This will create a computational mesh with approximately 2 meter resolution (1º in the latitude 47 is approximately 100 km).
Then, you need to save the grid file, by clicking in the lower-right button . After this you will be prompted to define the target path and filename. For the sake of the workspace organization, grid data file should be saved in the “C:\OpenFlows FLOOD Quick Start Guide\Projects\New Domain\General Data\Digital Terrain\grid.grd”.
When the tool closes, the grid remains loaded in the Map Window:
Figure 3 – Created grid / Map visualization