Title Hazard assessment investigations in connection with the formation of a lake on the tongue of Unterer Grindelwaldgletscher, Bernese Alps, Switzerland
Author Werder, M.A.; Bauder, A.; Funk, M.; Keusen, H.
Author Affil Werder, M.A., Eidgenössische Technische Hochschule-Zürich, Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie, Zurich, Switzerland. Other: GEOTEST, Switzerland
Source Natural Hazards and Earth System Sciences (NHESS), 10(2), p.227-237, . Publisher: Copernicus GmbH on behalf of the European Geophysical Society, Katlenburg- Lindau, Germany. ISSN: 1561- 8633
Publication Date 2010
Notes In English. Accessed in Nov., 2010; abstract: doi:10.5194/nhess-10-227-2010. 23 refs. GeoRef Acc. No: 309750
Index Terms dams; flooding; glacial lakes; glaciers; hydrography; ice dams; lakes; mass movements (geology); meltwater; models; warning systems; Switzerland--Bernese Alps; Switzerland--Grindelwald; Alps; Bernese Alps; Central Alps; Central Europe; climate effects; debris; digital terrain models; early warning systems; Europe; flash floods; floods; geologic hazards; glacial features; Grindelwald; hydrographs; jokulhlaups; mass movements; natural dams; natural hazards; risk assessment; rockfalls; Spring-Hutter equations; Switzerland; Unterer Grindelwaldgletscher
Abstract The surface of Unterer Grindelwaldgletscher glacier tongue has subsided by more than 200 m over the last 150 years. The surface lowering is not uniform over the glacier tongue but depends on the thickness of the uneven debris cover, which led to the formation of a depression on the tongue. A lake can form in this basin, which occurred for the first time in 2005. Such a glacier lake can drain rapidly leading to a so-called outburst flood. The lake basin has been increasing in size at an alarming rate and in 2008, it reached a volume which poses a significant flooding threat to the communities downstream, as was exemplified by an outburst of the lake in May 2008. The future evolution of the lake basin was extrapolated based on surface lowering rates between 2004-2008. An outburst flood model was tuned with the measured hydrograph from 2008 and then was run with the extrapolated lake bathymetries to simulate future lake outbursts and estimate their flood hydrographs. We discuss the rapidly increasing risk for Grindelwald and other communities, as well as the installation of an early warning system and possible prevention measures.
URL http://www.nat-hazards-earth-syst-sci.net/10/227/2010/nhess-10-227-2010.pdf
Publication Type journal article
Record ID 65006362