Hazards in mountainous terrain: Lessons for linear infrastructure from the Canadian forest industry

摘要

British Columbia, on the mountainous western coast of Canada, has a network of infrastructure routes that must contend daily with the difficult and hazardous terrain that dominates the province. The forest industry, which operates in the mountains in remote, undeveloped mountainous areas, also faces such terrain challenges. Landslide frequencies following logging have been documented as being approximately ten times that prior to logging, with landslide densities increasing by as much as 94 times as a result of the road development associated with the logging. In 1995 British Columbia introduced the Forest Practices Code, part of which required that Terrain Hazard maps were required for all areas of proposed forest harvesting or road construction. The industry is currently preparing for and starting to implement a new 'Results-based' Forest Practices Code which requires that the licence-holders "…ensure that the primary forest activity does not cause a landslide that has a material adverse effect…" to the forest resource. By describing the approaches adopted in the forestry industry of British Columbia this paper aims to illustrate some lessons that are relevant to the design and construction of major pipelines and roads in landslide-prone mountainous terrain.