Vulnerability to jökulhlaup hazards: A case study of the Þjórsá floodplain, Southern Iceland

The 2014-2015 eruption at the subglacial Barðarbunga volcanic system heightened awareness of volcanic hazards, particularly to the potential impacts of jökulhlaups. One area in southern Iceland, located around the Þjórsá River and bordered by the Hvítá and Rangá rivers, is particularly vulnerable to the effects of a potential jökulhlaup. Vulnerability of the human, natural, and built environments was investigated, analysed, and mapped using GIS methods using data from the engineering company Verkís and by Landsvirkjun, as well as from Statistics Iceland, OpenStreetMap, the National Land Survey of Iceland and the Icelandic Institute of Natural History. Visualisation of risk and vulnerability as a communication tool is discussed. Vulnerability depends on a wide range of factors, ranging from social factors such as a person’s country of origin to physical factors such as the location of their residence within the floodplain. Out of the four municipalities, Flóahreppur, Skeiða- og Gnúpverjahreppur, Ásahreppur and Rangárþing ytra, intersecting the Affected Area, Flóahreppur municipality was found to be the most vulnerable, due to the higher proportion of cultivated agricultural, horticultural, and domestic habitats and grassland upon which people depend on for their livelihoods, in addition to a higher population and infrastructure density. Results can be used by planners and policy makers to improve community awareness and preparation in the event of a future jökulhlaups