Application of an UAV for 3D modelling
Skid trails constructed for timber extraction in steep terrain can constitute an environmental concern if not well planned and executed. Carrying out post-harvest surveys in monitoring constructed trails in such terrain is an onerous task for forest management and values are largely based on assumptions of trail symmetry and terrain uniformity.
In this Norwegian Forest and Landscape Institute study, aerial imagery captured from a multi-rotor Unmanned Aerial Vehicle (UAV) was used in generating a detailed post-harvest terrain model which included all skid trails. This was then compared with an Airborne Laser Scanning derived pre-harvest terrain model and the dimensions, slopes and cut-and-fill volumes associated with the skid trails were determined.
The methods used in this work can be used in rapidly assessing the extent of disturbance and erosion risk on a wide range of sites. The multi-rotor UAV was found to be highly suited to the task, given the relatively small size of harvested stands, their shape and their location in the mountainous terrain.
Image credit: MDPI