Aerial photo-interpretation as a tool in arterial forest road location

Abstract

Escalating distances of harvesting sites from mills, truck operating costs and road construction costs are all contributing to the increased importance of optimizing arterial road layout. This optimization is achieved by determining the roads requirements and specifications and by selecting the ultimate route alignment according to the forest topography. The process of fitting a specified type of road to the topography is a matter of both qualitative and quantitative evaluation. This evaluation can be accomplished most efficiently through the use of aerial photographs. Photo-interpretation of aerial photographs augmented by photogrammetric treatment and some ground surveying produces the most complete method of coverage. This allows controls, ground slopes, drainage patterns, building materials and soil types to be identified. For the final location, topographic maps prepared from large scale photos along with the photos themselves enable the surveyor to establish the route to within the required accuracy on the ground.