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Tiefgreifende Hangdeformation am südlichen Heinzenberg
Author(s) -
Osten Julian,
Küppers Jan,
Dufresne Anja,
Huwiler Andreas,
Amann Florian
Publication year - 2020
Publication title -
geomechanics and tunnelling
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.317
H-Index - 18
eISSN - 1865-7389
pISSN - 1865-7362
DOI - 10.1002/geot.201900065
Subject(s) - debris , geology , landslide , current (fluid) , hydrogeology , erosion , hydrology (agriculture) , debris flow , drainage , geomorphology , geotechnical engineering , oceanography , ecology , biology
Geotechnical assessment of the refilling of the Lüschersee A mass movement of several m/year towards the Nolla stream was detected at the southern Heinzenberg (Grisons, Switzerland) in the 19 th century. Debris flows originating from the upper stream valley reached the Hinterrhein valley at irregular intervals, creating temporary dams, which raised the river > 10 m above normal levels. Since 1870, comprehensive mitigation strategies, including torrent control and drainage of the 3‐ha Lüschersee lake situated in the landslide area, have reduced the deformation velocity to approx. 4.3 cm/year and prevented further debris flows. Whether draining of the Lüschersee has influenced the slope deformation was debated back then and has not been conclusively resolved till this day. A potential use of the lake to store water for the local ski area makes the topic current. The integration of geological data with the results of numerical simulations shows that both the mechanical effect of the artificially raised riverbed and the subsequently reduced erosion have a positive influence on the slope, although the effects of changing the hydrogeological situation by refilling the Lüschersee remain uncertain. Therefore, the decision on refilling is dependent on a successful test filling accompanied by permanent GPS measurements.