Floods in the Ölfusá basin, Iceland: A geographic contribution to the assessment of flood hazard and management of flood risk

• Main Author: Pagneux, Emmanuel P., 1972-
• Other Authors: Háskóli Íslands
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2011
• Subjects: Doktorsritgerðir; Líf- og umhverfisvísindi; Landfræði; Ölfusá; Flóð; Flóðahætta; Rennsli; Hvítá; Iceland; Selfoss
• Online Access: http://hdl.handle.net/1946/10224

This research is a geographic exploration of the physical and societal components of flood risk in the Ölfusá basin, Southern Iceland. Two specific aspects were investigated: - Impact of ice jams on the extent, boundaries, and depth of historical floods; - Public perception of flood hazard and flood risk and public preferences in the management of flood risk in the town of Selfoss. The research on historical floods indicates that discharge at gauging sites is not a reliable parameter for flood hazard mapping, as the extent and boundaries of ice-jam floods depend essentially on the location and nature of ice jams that form at specific sections of the Hvítá-Ölfusá river complex. Accurate delineation of flood hazard zones is accessible without monitoring of ice-jamming sites, based on reconstructions at high resolution of past ice-jam floods, which provide robust information on the extent and depth of extreme flooding events. The research on flood risk perception indicates that public awareness of flood hazard is insufficient and shows the need for improved information sharing on the outcome of inundations induced by ice jams, whose genesis and boundaries are unknown to an important part of the population. The study on public preferences in the management of flood risk suggests that the population surveyed favours polycentric governance, restrictions in land use planning, and actions centred on the people: passive measures, which are individual solutions applicable at the home level. Flóð á vatnasviði Ölfusár eru mismunandi og hafa margvíslegar afleiðingar í för með sér. Í rannsókninni er beitt landræðilegum aðferðum við mat á náttúrufarslegum og samfélagslegum þáttum flóðahættu á vatnasviði Ölfusár. Þeir þættir sem sérstaklega voru rannsakaðir eru: - Áhrif jakastíflna á umfang, mörk og dýpi flóða; - Viðhorf almennings til flóða og flóðahættu og jafnframt hvaða kosti almenningur teldi vænlegasta varðandi skipulag flóðamála á Selfossi. Niðurstöður rannsóknarinnar sýna að rennsli á vatnshæðarmælistað nýtist ekki ...