Assessing the relationship between weather conditions and rockfall using terrestrial laser scanning to improve risk management
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Published:2023-01-27
Issue:1
Volume:23
Page:343-360
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ISSN:1684-9981
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Container-title:Natural Hazards and Earth System Sciences
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language:en
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Short-container-title:Nat. Hazards Earth Syst. Sci.
Author:
Birien Tom,Gauthier Francis
Abstract
Abstract. Since 1987, more than 13 200 rockfalls have been inventoried by the ministère des Transports du Québec (MTQ) as having impacted the national road Route 132 in northern Gaspésie. This natural hazard represents a nearly
permanent danger for road users. Traditional mitigation measures can be
ineffective on poorly consolidated, deformed and highly fractured rockwalls
such as those found in northern Gaspésie. To address this issue,
implementing preventive risk management based on the factors that trigger
rock instabilities could be the most effective method. Earthquake, rainfall
and freeze–thaw cycles are commonly considered to be the main rockfall-triggering factors. This study aims to better understand the climatic
conditions conducive to rockfalls in northern Gaspésie in order to
provide knowledge to implement an appropriate risk management strategy.
Three rockwalls were scanned with terrestrial laser scanning (TLS) instruments during
specific pre-targeted weather conditions. Over a period of 18 months, 17
surveys have allowed us to identify 1287 rockfalls with a magnitude above
0.005 m3 on a scanned surface of 12 056 m2.
In addition, meteorological instruments and a 550 cm thermistor string have been installed directly on a vertical rockwall. It appears that some weather conditions influence the occurrence, frequency and magnitude of rockfalls. In winter, rockfall frequency is 12 times higher during a superficial thaw than
during a cold period in which temperature remains below 0 ∘C. In
summer, rockfall frequency is 22 times higher during a heavy rainfall event
than during a mainly dry period. Superficial freeze–thaw cycles (< 50 cm) cause mostly a high frequency of small-magnitude events, while deeper spring thaw (> 100 cm) results in a high frequency of large-magnitude events. The influence of weather conditions on rockfall frequency and magnitude is crucial in order to improve risk management, since large-magnitude events represent higher potential hazards. This study provides a classification of weather conditions based on their ability to trigger rockfalls of different magnitudes. This knowledge could be used to implement a risk management strategy.
Funder
Ministère des Transports
Publisher
Copernicus GmbH
Subject
General Earth and Planetary Sciences
Reference87 articles.
1. Abellán, A., Oppikofer, T., Jaboyedoff, M., Rosser, N. J., Lim, M., and Lato, M. J.: Terrestrial laser scanning of rock slope instabilities, Earth Surf. Proc. Land., 39, 80–97, https://doi.org/10.1002/esp.3493, 2014. 2. André, M. F.: Holocene rockwall retreat in Svalbard: a triple-rate
evolution, Earth Surf. Proc. Land., 22, 423–440,
https://doi.org/10.1002/(SICI)1096-9837(199705)22:5<423::AID-ESP706>3.0.CO;2-6, 1997. 3. Badger, T. C. and Lowell, S. M.: Rockfall Control in Washington State,
rockfall prediction and control and landslide case histories, Transp. Res.
Rec., 1343, 14–19, 1992. 4. Badoux, A., Andres, N., Techel, F., and Hegg, C.: Natural hazard fatalities in Switzerland from 1946 to 2015, Nat. Hazards Earth Syst. Sci., 16, 2747–2768, https://doi.org/10.5194/nhess-16-2747-2016, 2016. 5. Ballantyne, C. K. and Kirkbride, M. P.: Rockfall activity in upland Britain
during the Loch Lomond Stadial, Geogr. J., 153, 86–92,
https://doi.org/10.2307/634474, 1987.
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