Influence of snow and meteorological conditions on snow-avalanche
deposit volumes and consequences for road-network vulnerability
Snow avalanches are a major component of the mountain cryosphere that
frequently create a menace for the road network. Deposit characteristics
determine the extent of damage and disruption to communication networks,
but the factors controlling snow-deposit volumes remain largely unknown.
This study investigates the influence of meteorological and snowpack
conditions on snow-avalanche deposits and road-network vulnerability
based on 1986 deposit volumes from 182 paths located in two regions of
the French Alps between 2003 and 2017: Guil and Haute-Maurienne valleys.
During the period, 195 avalanches impacted the road network in these
areas, leading to major disruptions. In Haute-Maurienne, correlations
between deposit volumes and meteorological and snowpack conditions are
high in winter. However, the relationships differ with path elevation
and orientation. Results do not show any significant relationship
between volumes and meteorological or snowpack conditions for the spring
season. Focusing on deposits that disturbed the road network, winter and
spring reveal a distinct influence of meteorological and snow variables
compared to the overall data set, with snowfall intensity as the
predominant control variable of deposit volumes leading to road cuts.
When the same analysis is conducted by considering Guil valley
separately or by aggregating Haute-Maurienne with Guil valley area data,
results do not show any significant relationship, highlighting the
specific regional nature of relations between deposit volumes and
meteorological and snowpack conditions.