Investigating decadal-scale geomorphic dynamics in an alpine mountain setting

Details

Serval ID
serval:BIB_BC10CCE43AD5
Type
Article: article from journal or magazin.
Collection
Publications
Title
Investigating decadal-scale geomorphic dynamics in an alpine mountain setting
Journal
Journal of Geophysical Research: Earth Surface
Author(s)
Micheletti  Natan, Lambiel  Christophe, Lane  Stuart N.
Publication state
Published
Issued date
2015
Peer-reviewed
Oui
Volume
120
Number
10
Pages
2155-2175
Abstract
We know little about the effect of recent climate variability upon landscapes at the timescale of decades because of (1) the complex, nonlinear, and path-dependent nature of the response of a landscape to climate forcing and (2) the difficulty of quantifying spatially distributed impacts at the timescale of decades to centuries, despite this being the timescale over which significant hypotheses have been raised over human impacts upon climate change and hence geomorphic systems. A unique resource to investigate the linkages between climatic variability and geomorphic response is provided by the extensive coverage of aerial imagery commonly available since the 1950s. Here we use archival digital photogrammetry to produce high-precision digital elevation models over large spatial scales, and so to reconstruct the quantitative history of surface downwasting and sediment flux in a high mountain alpine system, over the timescales of decades. Propagation of error methods is used to identify locations of significant landscape response and to compute volumes of significant surface change. Orthorectified aerial
images are used in an image correlation framework to detect horizontal and vertical displacements of components of the landscape. Results are coupled to extant climate data and modeled snow cover to show how the landscape responds to climate forcing and to geomorphological maps to understand how this response varies between landscape elements. The results show distinct landscape response to both warming and cooling periods and a tendency for the acceleration of surface displacement under warming conditions. Precipitation and snow cover are critical in controlling glacier dynamics and rock glacier displacement velocities. However, while some landforms might lead to locally high sediment flux, landscape heritage can disconnect zones of high change rates from the valley bottom. Hence, the landscape response to climate forcing is not necessarily reflected in valley system processes or sediment deposits.
Create date
02/04/2015 9:33
Last modification date
20/08/2019 16:30
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