How to use the forest model to simulate a forest
Map
If your selected area has a forest present like in the below example it can be useful to use the forest modelling to refine your simulation. When editing the roughness values for make sure that the wanted forest has an unique roughness value. This can be anything as the model will use the forest cells in the area instead of the roughness length.
Right click the forest to select it and set the roughness value as below.
Note! It is important that it has an unique roughness value as Model will set all of a certain roughness length to be the forest.
Model
- Open the Forest widget on the left pane
- Click Add Forest
- Enter Forest Values, remember that the roughness to use must be the unique roughness length from the Map module
- Click 'Create 3D Model'
- In the result pane check the Forest box and see that the forest is located have the correct area and shape.
Vertical Grid and Forest
When enabling the forest the bottom layer of cells are completely controlled by the forest configuration, then the geometrical distribution is then used for the cells above that.
The grid(z) should show you the exact distribution.
In this example a forest was defined with 4 cells of 5 meters.
That means that it creates 4 cells of 5 meters, i.e. the first shows as 2.5 since it measures the height from ground to center of cell.
The forest cells has uniform height over the entire horizontal domain
Then the geometric expansions starts after those cells. The cells distributed by the geometric distribution have different height over the horizontal domain to make sure the model ends at the same vertical height.
Multiple Forests
If there are multiple forests defined the cell heights must match
Forest 1 has 10 meter height and 2 cells. If a second forest is of height 20 it must be contructed of 4 cells, so the 2 forest align on the bottom 2 cells.
| Forest 1: | 5m | 10m | ||
| Forest 2 | 5m | 10m | 15m | 20m |
Forest 1: 5;10
Forest 2: 5;10;15;20
Proceed to Wind Fields as usual.