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| Titel |
Repeated glacial lake outburst flood threatening the oldest Buddhist monastery in north-western Nepal |
| VerfasserIn |
J. Kropáček, N. Neckel, B. Tyrna, N. Holzer, A. Hovden, N. Gourmelen, C. Schneider, M. Buchroithner  , V. Hochschild |
| 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 ; 15, no. 10 ; Nr. 15, no. 10 (2015-10-26), S.2425-2437 |
| Datensatznummer |
250119727
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| Publikation (Nr.) |
 copernicus.org/nhess-15-2425-2015.pdf |
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| Zusammenfassung |
| Since 2004, Halji village, home of the oldest Buddhist Monastery in
north-western Nepal, has suffered from recurrent glacial lake outburst floods
(GLOFs). A sudden englacial drainage of a supraglacial lake, located at a
distance of 6.5 km from the village, was identified as the source of the
flood. The topography of the lake basin was mapped by combining differential
Global Positioning System (DGPS) measurements with a structure-from-motion
(SFM) approach using terrestrial photographs. From this model the maximum
filling capacity of the lake has been estimated as 1.06 ×10^6 m3
with a maximum discharge of 77.8 m3 s−1, calculated using the
empiric Clague–Mathews formula. A simulation of the flooded area employing a
raster-based hydraulic model considering six scenarios of discharge volume
and surface roughness did not result in a flooding of the village. However,
both the village and the monastery are threatened by undercutting of the river
bank formed by unconsolidated sediments, as it already happened in 2011.
Further, the comparison of the GLOF occurrences with temperature and
precipitation from the High Asia Reanalysis (HAR) data set for the period
2001–2011 suggests that the GLOF is climate-driven rather than generated by
an extreme precipitation event. The calculation of geodetic mass balance and
the analysis of satellite images showed a rapid thinning and retreat of Halji
Glacier which will eventually lead to a decline of the lake basin. As the
basin will persist for at least several years, effective mitigation measures
should be considered. A further reinforcement of the gabion walls was
suggested as an artificial lake drainage is not feasible given the difficult
accessibility of the glacier. |
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