Snow-avalanche and debris-flow hazards in the fjords of north-western Iceland, mitigation and prevention

In the fjords of north-western Iceland, snow-avalanche and debris-flow hazards threaten 65% of the inhabitants. In this area, both historical and geomorphological evidences clearly demonstrate the recurrent danger from the steep slopes. Hazard vulnerability has increased during the last century, in connection with the population development of the Westfjords. Two snow-avalanche disasters during 1995 (in which 34 people were killed in two villages) prompted efforts to both mitigate and prevent future snow-avalanche and debris-flow activity. Research (qualitative and quantitative) on process characteristics describes prone terrain, runout distance, process behaviour along the slope, morphometric properties of the deposits and triggering factors. Acceptable risk, hazard and risk zoning are clearly defined by official regulations. Evacuation plans are determined from statistical characterisation of the risk and dynamic numerical modelling. To enhance the risk reduction, permanent and temporary measures aim to control the processes and to protect the population.