Hazard and risk assessment for early phase road planning in Norway

The study presented in this paper is carried out for a state-owned Norwegian road company, Nye Veier AS, to assess potential natural hazards and their consequences along ca. 720 km of planned roads at the early planning stage, before the final route is fixed. This paper focuses on the GIS based tool for early assessment of hazards, and the methods of optimizing the available data, as well as how the results were communicated to the client, an important part of the project. The output is an outline of the most critical locations and serves to limit the extent of necessary field work.

The following consequence evaluation quantified the indirect economic consequences of closed road and assessed the consequence for emergency preparedness qualitatively. Other consequences were not considered in the study. Climate change was considered and evaluated to affect the probability for flooding and debris flows, whereas the link between climate change and the other assessed hazards was considered too uncertain to impact on the risk estimates. Results of the study were communicated through an interactive map solution, with key results presented as fact sheets activated in the map for each risk section of the roads.