Modelling and verification of the permafrost distribution in the Bernese Alps (Western Switzerland)

Imhof, Markus

doi:10.1002/(sici)1099-1530(199609)7:3<267::aid-ppp221>3.0.co;2-l

Cited by 68 publications

(34 citation statements)

References 7 publications

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“…These relationships were first implemented within a GIS environment by Keller (1992) and later incorporated in further studies to predict spatial permafrost occurrence (Imhof, 1996;Frauenfelder et al, 1998;BAFU, 2005;Ebohon and Schrott, 2008). Besides topographic variables, climatic information and other direct proxy variables of the surface energy balance (such as MAAT and PISR) are often used in statistical or empirical permafrost models.…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

“…Measurements in boreholes and near the ground surface have been used for model evaluation (Gruber et al, 2004;Heggem et al, 2005;Etzelmüller et al, 2006Etzelmüller et al, , 2007Allen et al, 2009). Other studies used rock glacier inventories to infer the occurrence of permafrost (Janke, 2004), to identify the lower boundary of discontinuous permafrost (Nyenhuis et al, 2005), or for model assessment (Imhof, 1996;Gruber and Hoelzle, 2001).…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

“…Many models already exist for estimating the spatial distribution of mountain permafrost in regions of the European Alps (Hoelzle, 1992;Keller, 1992;Imhof, 1996;Gruber and Hoelzle, 2001;Lambiel and Reynard, 2001;BAFU, 2005). These models are difficult to compare or combine because they have different empirical or statistical approaches and differing types of indices as output.…”

Section: Introductionmentioning

confidence: 99%

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A statistical approach to modelling permafrost distribution in the European Alps or similar mountain ranges

et al. 2012

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Abstract.Estimates of permafrost distribution in mountain regions are important for the assessment of climate change effects on natural and human systems. In order to make permafrost analyses and the establishment of guidelines for e.g. construction or hazard assessment comparable and compatible between regions, one consistent and traceable model for the entire Alpine domain is required. For the calibration of statistical models, the scarcity of suitable and reliable information about the presence or absence of permafrost makes the use of large areas attractive due to the larger data base available.We present a strategy and method for modelling permafrost distribution of entire mountain regions and provide the results of statistical analyses and model calibration for the European Alps. Starting from an integrated model framework, two statistical sub-models are developed, one for debris-covered areas (debris model) and one for steep bedrock (rock model). They are calibrated using rock glacier inventories and rock surface temperatures. To support the later generalization to surface characteristics other than those available for calibration, so-called offset terms have been introduced into the model that allow doing this in a transparent and traceable manner.For the debris model a generalized linear mixed-effect model (GLMM) is used to predict the probability of a rock glacier being intact as opposed to relict. It is based on the explanatory variables mean annual air temperature (MAAT), potential incoming solar radiation (PISR) and the mean annual sum of precipitation (PRECIP), and achieves an excellent discrimination (area under the receiver-operating characteristic, AUROC = 0.91). Surprisingly, the probability of a rock glacier being intact is positively associated with increasing PRECIP for given MAAT and PISR conditions. The rock model is based on a linear regression and was calibrated with mean annual rock surface temperatures (MARST). The explanatory variables are MAAT and PISR. The linear regression achieves a root mean square error (RMSE) of 1.6 • C. The final model combines the two sub-models and accounts for the different scales used for model calibration.The modelling approach provides a theoretical basis for estimating mountain permafrost distribution over larger mountain ranges and can be expanded to more surface types and sub-models than considered, here. The analyses performed with the Alpine data set further provide quantitative insight into larger-area patterns as well as the model coefficients for a later spatial application. The transfer into a mapbased product, however, requires further steps such as the definition of offset terms that usually contain a degree of subjectivity.

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Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A statistical approach to modelling permafrost distribution in the European Alps or similar mountain ranges

et al. 2012

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“…Hoelzle, 1994;Imhof, 1996;Frauenfelder, 1998;Keller et al, 1998;Gruber and Hoelzle, 2001;Lambiel and Reynard, 2001;BAFU, 2005;Bodin, 2007;Ebohon and Schrott, 2008). Modelling strategies are not limited to the European Alps but have been developed for and applied to different mountain regions (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…PERMAKART (Keller, 1992) and PERMAMAP (Hoelzle, 1992;Hoelzle et al, 1993) were the first modelling approaches in the Alps that related topographic and climatic variables to the existence of permafrost and that provided map-based products to visualize permafrost distribution. Both models have been applied to various regions, and the basic relationships have been used/adapted for the development of further models (Imhof, 1996;BAFU, 2005;Ebohon and Schrott, 2008). As output, both models provide gridded data spatially predicting permafrost occurrence by using discrete classification schemes.…”

Section: Introductionmentioning

confidence: 99%

Permafrost distribution in the European Alps: calculation and evaluation of an index map and summary statistics

et al. 2012

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Abstract. The objective of this study is the production of an Alpine Permafrost Index Map (APIM) covering the entire European Alps. A unified statistical model that is based on Alpine-wide permafrost observations is used for debris and bedrock surfaces across the entire Alps. The explanatory variables of the model are mean annual air temperatures, potential incoming solar radiation and precipitation. Offset terms were applied to make model predictions for topographic and geomorphic conditions that differ from the terrain features used for model fitting. These offsets are based on literature review and involve some degree of subjective choice during model building. The assessment of the APIM is challenging because limited independent test data are available for comparison and these observations represent point information in a spatially highly variable topography. The APIM provides an index that describes the spatial distribution of permafrost and comes together with an interpretation key that helps to assess map uncertainties and to relate map contents to their actual expression in the terrain. The map can be used as a first resource to estimate permafrost conditions at any given location in the European Alps in a variety of contexts such as research and spatial planning.Results show that Switzerland likely is the country with the largest permafrost area in the Alps, followed by Italy, Austria, France and Germany. Slovenia and Liechtenstein may have marginal permafrost areas. In all countries the permafrost area is expected to be larger than the glacier-covered area.

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Permafrost changes in rock walls and the retreat of alpine glaciers: a thermal modelling approach

Wegmann

Gudmundsson

Haeberli

1998

Permafrost Periglac. Process.

134

138

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The shrinkage of Grosser Aletschgletscher changed the thermal and mechanical boundary conditions in its marginal rock walls. The temperature at the glacier bed is at the pressure melting point while the exposed rock surface (above the glacier) is subject to atmospheric conditions. At our study site, a north‐facing rock wall at Konkordiaplatz, the surface temperatures have cooled below the freezing point during glacier retreat. Sensitivity studies on the thermal evolution and the permafrost dynamics in the bedrock involve heat transfer models with changing glacier surface and rock surface temperatures. They indicate that even small amounts of moisture limit the permafrost dynamics to the surface decametres at secular time scale. The calculations further indicate that, in the investigated rock wall, permafrost is penetrating as a consequence of the glacier retreat. The delay of the response of the permafrost base is in the order of millennia. Freezing and thawing of rock moisture leads to frost damage. The model results predict areas of frost shattering in the surface decametres and in the region of the permafrost base. The frost action is also favoured by unloading during glacier recession. © 1998 John Wiley & Sons, Ltd.

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Modelling and verification of the permafrost distribution in the Bernese Alps (Western Switzerland)

Cited by 68 publications

References 7 publications

A statistical approach to modelling permafrost distribution in the European Alps or similar mountain ranges

A statistical approach to modelling permafrost distribution in the European Alps or similar mountain ranges

Permafrost distribution in the European Alps: calculation and evaluation of an index map and summary statistics

Permafrost changes in rock walls and the retreat of alpine glaciers: a thermal modelling approach

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