Spatiotemporal patterns of high-mountain lakes and related hazards in western Austria

0453799 - ÚVGZ 2016 RIV NL eng J - Článek v odborném periodiku
Emmer, Adam - Merkl, S. - Mergili, M.
Spatiotemporal patterns of high-mountain lakes and related hazards in western Austria.
Geomorphology. Roč. 246, oct (2015), s. 602-616. ISSN 0169-555X. E-ISSN 1872-695X
Institucionální podpora: RVO:67179843
Klíčová slova: lake development * geoenvironmental change * GLOF * high-mountain lakes * susceptibility analysis
Kód oboru RIV: DE - Zemský magnetismus, geodézie, geografie
Impakt faktor: 2.813, rok: 2015

Climate-induced environmental changes are triggering the dynamic evolution of high-mountain lakes worldwide, a phenomenon that has to be monitored in terms of lake outburst hazards.We analyzed the spatial distribution and recent temporal development of high-mountain lakes in a study area of 6139 km2, covering the central European Alps (Tyrol). We identified 1024 lakes. While eight lakes are ice-dammed, one-third of all lakes are located in the immediate vicinity of recent glacier tongues, half of them impounded by moraines, half by bedrock. Two-thirds of all lakes are apparently related to LIA or earlier glaciations. One landslide-dammed lake was identified in the study area. The evolution of nine selected (pro)glacial lakeswas analyzed in detail, usingmultitemporal remotely sensed images and field reconnaissance. Considerable glacier retreat led to significant lake growth at four localities, two lakes experienced stagnant or slightly negative areal trends, one lake experienced a more significant negative areal trend, and two lakes drained completely during the investigation period. We further (i) analyzed the susceptibility of selected lakes to glacial lake outburst floods (GLOFs), using two different methods; (ii) identified potential triggers and mechanisms of GLOFs; (iii) calculated possible flood magnitudes for predefined flood scenarios for a subset of the lakes; and (iv) delineated potentially impacted areas. We distinguished three phases of development of bedrock-dammed lakes: (a) a proglacial, (b) a glacierdetached, and (c) a nonglacial phase. The dynamics — and also the susceptibility of a lake to GLOFs — decrease substantially from (a) to (c). Lakes in the stages (a) and (b) are less prominent in our study area, compared to other glacierized high-mountain regions, leading us to the conclusion that (i) the current threat to the population by GLOFs is lower but (ii) the future development of emerging lakes has to be monitored carefully.
Trvalý link: http://hdl.handle.net/11104/0254633