Comparing optimal and actual forest road locations using least-cost analysis in QGIS

Abstract

For the Lakehead Forest licence, west of Thunder Bay, Ontario, a least-cost roads model was built in QGIS using provincial Digital Elevation Model (PDEM) data, and data provided by Greenmantle. A cost-surface was also generated from the PDEM using a script created in the ArcPy module of Python. The model identified the most cost-efficient routes for operational roads within a limited criterion, connecting terminal points in harvested stands to terminal points along primary access roads. The modelled roads were then compared to existing roads mirroring the modelled versions, to analyze whether differences were significant. The network of roads as a whole was significantly different at the 0.05-alpha level, while 41 of 42 individual road pairs were significantly different at the 0.05-alpha level.