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dc.contributor.authorGeorge, David L.
dc.contributor.authorIverson, Richard M.
dc.contributor.authorCannon, Charles M.
dc.date.accessioned2019-08-21T21:47:17Z
dc.date.available2019-08-21T21:47:17Z
dc.date.issued2019
dc.description.abstractNumerical simulations of hazard cascades downstream from moraine-dammed lakes commonly must specify linkages between models of discrete processes such as wave overtopping, dam breaching, erosion, and downstream floods or debris flows. Such linkages can be rather arbitrary and can detract from the ability to accurately conserve mass and momentum during complex sequences of events. Here we describe an alternative methodology in which we use high-resolution lidar topography and 2-D, two-phase conservation laws to seamlessly simulate all stages of a hazard-cascade that culminates in a debris flow. Our simulations employ our depth-integrated numerical model D- Claw to evaluate hazards from prospective breaching of a moraine dam that impounds Carver Lake on the eastern flank of South Sister volcano in central Oregon, USA. We simulate a “worst-case scenario” sequence of events that begins with a hypothetical 1.6 million m3 landslide that originates near the summit of South Sister and enters Carver Lake. Wave generation and displacement of lake water then leads to dam overtopping, breach erosion, and a downstream debris flow that funnels into Whychus Creek and eventually reaches the community of Sisters, Oregon, about 20 km away. Notably, our simulations predict that much of the debris is directed away from Sisters as a result of natural avulsion and flow diversion that occurs near the head of a low-gradient alluvial fan upstream from Sisters. Consequently, predicted hazards to downtown Sisters are less severe than those predicted by 1-D shallow-water simulations of a Carver Lake dam breach that were performed in the 1980s.
dc.format.mediumborn digital
dc.format.mediumproceedings (reports)
dc.identifier.urihttps://hdl.handle.net/11124/173208
dc.identifier.urihttp://dx.doi.org/10.25676/11124/173208
dc.languageEnglish
dc.publisherColorado School of Mines. Arthur Lakes Library
dc.publisher.originalAssociation of Environmental and Engineering Geologists
dc.relation.ispartofSeventh International Conference on Debris-Flow Hazards Mitigation - Proceedings
dc.relation.ispartofAssociation of Environmental and Engineering Geologists; special publication 28
dc.rightsCopyright of the original work is retained by the authors.
dc.sourceContained in: Proceedings of the Seventh International Conference on Debris-Flow Hazards Mitigation, Golden, Colorado, USA, June 10-13, 2019, https://hdl.handle.net/11124/173051
dc.subjectdebris-flow modeling
dc.subjectLake-outburst floods
dc.subjectTwo-phase modeling
dc.subjectCarver Lake
dc.subjectSouth Sister volcano
dc.titleSeamless numerical simulation of a hazard cascade in which a landslide triggers a dam-breach flood and consequent debris flow
dc.typeText


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