Forest Damping

When rockfalls occur on a forested slope, impacts of rocks with trees or vegetation can reduce the speed and energy of rocks traveling down the slope.

The Forest Damping option is implemented as a slope material property (drag coefficient) as shown below. The Effective Height allows you to specify the tree height over which the damping will take place.

If you select the tree icon (beside the Drag Coefficient), a popup will allow you to estimate a value based on the average forest density (Bartelt et al, 2016). If you select Open, Medium or Dense forest, the corresponding drag coefficient will be automatically entered in the dialog. Or you can simply enter a value directly in the edit box.

Any rock paths travelling through the shaded area will have forest damping applied. You can define and assign different coefficients or effective heights to different segments of the slope, as required.

Notes:

• Forest Damping is only available if you are using the Rigid Body Analysis Method.
• Forest Damping has NOT been implemented for the Lump Mass Analysis Method.

Forest Damping Tutorial

See Tutorial 08 - Forest Damping in RocFall for a tutorial that illustrates the Forest Damping option.

Forest Damping Verification

See the Forest Damping verification document.

Forest Display Option

In the Display Options dialog, you can customize the colour or hatch pattern used to display the forest areas on the slope.

References

The forest damping model in RocFall is built on the theory developed by Leine et al [2013].