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| Titel |
Moraine-dammed lake failures in Patagonia and assessment of outburst susceptibility in the Baker Basin |
| VerfasserIn |
P. Iribarren Anacona, K. P. Norton, A. Mackintosh |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Sciences ; 14, no. 12 ; Nr. 14, no. 12 (2014-12-05), S.3243-3259 |
| Datensatznummer |
250118800
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| Publikation (Nr.) |
 copernicus.org/nhess-14-3243-2014.pdf |
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| Zusammenfassung |
| Glacier retreat since the Little Ice Age has resulted in the development or
expansion of hundreds of glacial lakes in Patagonia. Some of these lakes
have produced large (≥ 106 m3) Glacial Lake Outburst Floods
(GLOFs) damaging inhabited areas. GLOF hazard studies in Patagonia have been
mainly based on the analysis of short-term series (≤ 50 years) of flood
data and until now no attempt has been made to identify the relative
susceptibility of lakes to failure. Power schemes and associated
infrastructure are planned for Patagonian basins that have historically been
affected by GLOFs, and we now require a thorough understanding of the
characteristics of dangerous lakes in order to assist with hazard assessment
and planning. In this paper, the conditioning factors of 16 outbursts from
moraine-dammed lakes in Patagonia were analysed. These data were used to
develop a classification scheme designed to assess outburst susceptibility,
based on image classification techniques, flow routine algorithms and the
Analytical Hierarchy Process. This scheme was applied to the Baker Basin,
Chile, where at least seven moraine-dammed lakes have failed in historic time.
We identified 386 moraine-dammed lakes in the Baker Basin of which 28 were
classified with high or very high outburst susceptibility. Commonly, lakes
with high outburst susceptibility are in contact with glaciers and have
moderate (> 8°) to steep (> 15°)
dam outlet slopes, akin to failed lakes in Patagonia. The proposed
classification scheme is suitable for first-order GLOF hazard assessments in
this region. However, rapidly changing glaciers in Patagonia make detailed
analysis and monitoring of hazardous lakes and glaciated areas upstream from
inhabited areas or critical infrastructure necessary, in order to better
prepare for hazards emerging from an evolving cryosphere. |
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