Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods
We present an analysis of temporal trends in similar to 55 000 avalanches recorded between 1946 and 2010 in the French Alps and two north/south subregions. First, Bayesian hierarchical modelling is used to isolate low-, intermediate- and high-frequency trends in the mean avalanche occurrence and run...
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Online Access: | https://hal.archives-ouvertes.fr/hal-01019099 https://doi.org/10.3189/2013JoG12J091 |
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ftccsdartic:oai:HAL:hal-01019099v1 2023-05-15T16:57:26+02:00 Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods Eckert, N. Keylock, C. J. Castebrunet, H. LAVIGNE, Aurore Naaim, M. Eros Torrentielle Neige & Avalanches Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) Department of Civil and Structural Engineering Sheffield University of Sheffield Sheffield Mathématiques et Informatique Appliquées (MIA-Paris) AgroParisTech-Institut National de la Recherche Agronomique (INRA) French National Research Agency ANR-09-RISK-007-01 French Ministry of the Environment (Risk Division (DGPR); British Council; French Ministere des Affaires Etrangeres et Europeennes 2013 https://hal.archives-ouvertes.fr/hal-01019099 https://doi.org/10.3189/2013JoG12J091 en eng HAL CCSD International Glaciological Society info:eu-repo/semantics/altIdentifier/doi/10.3189/2013JoG12J091 hal-01019099 https://hal.archives-ouvertes.fr/hal-01019099 doi:10.3189/2013JoG12J091 IRSTEA: PUB00039483 PRODINRA: 211471 WOS: 000316373500011 ISSN: 0022-1430 Journal of Glaciology https://hal.archives-ouvertes.fr/hal-01019099 Journal of Glaciology, International Glaciological Society, 2013, 59 (213), pp.93 - 114. ⟨10.3189/2013JoG12J091⟩ HYDROMETEOROLOGICAL TIME-SERIES CHANGE-POINT ANALYSIS LAST 50 YEARS SNOW-COVER CLIMATE-CHANGE SWISS ALPS MODEL DEPTH FLUCTUATIONS VARIABILITY [SDV.SA]Life Sciences [q-bio]/Agricultural sciences info:eu-repo/semantics/article Journal articles 2013 ftccsdartic https://doi.org/10.3189/2013JoG12J091 2021-06-20T00:07:00Z We present an analysis of temporal trends in similar to 55 000 avalanches recorded between 1946 and 2010 in the French Alps and two north/south subregions. First, Bayesian hierarchical modelling is used to isolate low-, intermediate- and high-frequency trends in the mean avalanche occurrence and runout altitude per year/winter. Variables are then combined to investigate their correlation and the recent evolution of large avalanches. Comparisons are also made to climatic and flow regime covariates. The results are important for risk assessment, and the development of new high-altitude climate proxies. At the entire French Alps scale, a major change-point exists in similar to 1978 at the heart of a 10 year period of high occurrences and low runout altitudes corresponding to colder and snowier winters. The differences between this change-point and the beginning/end of the study period are 0.1 avalanche occurrences per winter and per path and 55 m in runout altitude. Trends before/after are well correlated, leading to enhanced minimal altitudes for large avalanches at this time. A marked upslope retreat (80 m for the 10 year return period runout altitude) accompanied by a 12% decrease in the proportion of powder snow avalanches has occurred since then, interrupted from about 2000. The snow-depth and temperature control on these patterns seems significant (R= 0.4-0.6), but is stronger at high frequencies for occurrences, and at lower frequencies for runout altitudes. Occurrences between the northern and southern French Alps are partially coupled (R similar to 0.4, higher at low frequencies). In the north, the main change-point was an earlier shift in similar to 1977, and winter snow depth seems to be the main control parameter. In the south, the main change-point occurred later, similar to 1979-84, was more gradual, and trends are more strongly correlated with winter temperature. Article in Journal/Newspaper Journal of Glaciology Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Journal of Glaciology 59 213 93 114 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
HYDROMETEOROLOGICAL TIME-SERIES CHANGE-POINT ANALYSIS LAST 50 YEARS SNOW-COVER CLIMATE-CHANGE SWISS ALPS MODEL DEPTH FLUCTUATIONS VARIABILITY [SDV.SA]Life Sciences [q-bio]/Agricultural sciences |
spellingShingle |
HYDROMETEOROLOGICAL TIME-SERIES CHANGE-POINT ANALYSIS LAST 50 YEARS SNOW-COVER CLIMATE-CHANGE SWISS ALPS MODEL DEPTH FLUCTUATIONS VARIABILITY [SDV.SA]Life Sciences [q-bio]/Agricultural sciences Eckert, N. Keylock, C. J. Castebrunet, H. LAVIGNE, Aurore Naaim, M. Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods |
topic_facet |
HYDROMETEOROLOGICAL TIME-SERIES CHANGE-POINT ANALYSIS LAST 50 YEARS SNOW-COVER CLIMATE-CHANGE SWISS ALPS MODEL DEPTH FLUCTUATIONS VARIABILITY [SDV.SA]Life Sciences [q-bio]/Agricultural sciences |
description |
We present an analysis of temporal trends in similar to 55 000 avalanches recorded between 1946 and 2010 in the French Alps and two north/south subregions. First, Bayesian hierarchical modelling is used to isolate low-, intermediate- and high-frequency trends in the mean avalanche occurrence and runout altitude per year/winter. Variables are then combined to investigate their correlation and the recent evolution of large avalanches. Comparisons are also made to climatic and flow regime covariates. The results are important for risk assessment, and the development of new high-altitude climate proxies. At the entire French Alps scale, a major change-point exists in similar to 1978 at the heart of a 10 year period of high occurrences and low runout altitudes corresponding to colder and snowier winters. The differences between this change-point and the beginning/end of the study period are 0.1 avalanche occurrences per winter and per path and 55 m in runout altitude. Trends before/after are well correlated, leading to enhanced minimal altitudes for large avalanches at this time. A marked upslope retreat (80 m for the 10 year return period runout altitude) accompanied by a 12% decrease in the proportion of powder snow avalanches has occurred since then, interrupted from about 2000. The snow-depth and temperature control on these patterns seems significant (R= 0.4-0.6), but is stronger at high frequencies for occurrences, and at lower frequencies for runout altitudes. Occurrences between the northern and southern French Alps are partially coupled (R similar to 0.4, higher at low frequencies). In the north, the main change-point was an earlier shift in similar to 1977, and winter snow depth seems to be the main control parameter. In the south, the main change-point occurred later, similar to 1979-84, was more gradual, and trends are more strongly correlated with winter temperature. |
author2 |
Eros Torrentielle Neige & Avalanches Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) Department of Civil and Structural Engineering Sheffield University of Sheffield Sheffield Mathématiques et Informatique Appliquées (MIA-Paris) AgroParisTech-Institut National de la Recherche Agronomique (INRA) French National Research Agency ANR-09-RISK-007-01 French Ministry of the Environment (Risk Division (DGPR); British Council; French Ministere des Affaires Etrangeres et Europeennes |
format |
Article in Journal/Newspaper |
author |
Eckert, N. Keylock, C. J. Castebrunet, H. LAVIGNE, Aurore Naaim, M. |
author_facet |
Eckert, N. Keylock, C. J. Castebrunet, H. LAVIGNE, Aurore Naaim, M. |
author_sort |
Eckert, N. |
title |
Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods |
title_short |
Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods |
title_full |
Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods |
title_fullStr |
Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods |
title_full_unstemmed |
Temporal trends in avalanche activity in the French Alps and subregions: from occurrences and runout altitudes to unsteady return periods |
title_sort |
temporal trends in avalanche activity in the french alps and subregions: from occurrences and runout altitudes to unsteady return periods |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.archives-ouvertes.fr/hal-01019099 https://doi.org/10.3189/2013JoG12J091 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
ISSN: 0022-1430 Journal of Glaciology https://hal.archives-ouvertes.fr/hal-01019099 Journal of Glaciology, International Glaciological Society, 2013, 59 (213), pp.93 - 114. ⟨10.3189/2013JoG12J091⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3189/2013JoG12J091 hal-01019099 https://hal.archives-ouvertes.fr/hal-01019099 doi:10.3189/2013JoG12J091 IRSTEA: PUB00039483 PRODINRA: 211471 WOS: 000316373500011 |
op_doi |
https://doi.org/10.3189/2013JoG12J091 |
container_title |
Journal of Glaciology |
container_volume |
59 |
container_issue |
213 |
container_start_page |
93 |
op_container_end_page |
114 |
_version_ |
1766048986134740992 |