July 2015
The author of the paper on which this case study is based: Mircea Voiculescu, West University of Timisoara, Romania
Appeared in: Area: Volume 46, Issue 3
Reference: Voiculescu, M. (2014) Patterns of the dynamics of human-triggered snow avalanches at the Făgăraş massif (Southern Carpathians), Romanian Carpathians, Area 46, p328-336
The Făgăraş massif and the Bâlea glacial area are found in the eastern region of the Southern Carpathian Mountains of Romania. The area, which receives on average more than one hundred and sixty snow days a year, covers approximately 1500km2 and is a large ridge of between seventy and eighty kilometres long. The frequency with which dangerous avalanches occur in the mountains is comparable with the rest of Europe and North America, yet observations of their causes in this region are relatively understudied. This is particularly true of the relationship between human and natural causes of fatality and injury during avalanche events.
A number of natural factors contribute to whether there is a risk of an avalanche occurring, as well as its potential size and severity. The elevation of a slope determines the extent and depth of snow a site is likely to receive (Maggioni and Gruber, 2003) with higher elevations receiving more snow (and avalanche activity) than those at lower altitudes. Snow depth is also determined by aspect: slopes that dominantly face the wind are less able to retain their snow cover, while those are more sheltered are more likely to have a greater depth of snow (McClung and Schaerer, 2006). Gravity acts most acutely on these snow packs between the angle of 25° and 50° (McClung and Schaerer, 2006), creating a higher risk of avalanches occurring at these gradients.
While nature may establish the conditions for a potential avalanche, human actions may trigger their actual occurrence. Mountain users are most exposed to avalanche risk while they are undertaking recreational activities (Jamieson and Stethem, 2002), with climbers, off-piste skiers (those who ski on slopes that have not been officially designated as ski-runs) and snowboarders most likely to suffer injuries or fatalities as a result of an avalanche, often after being buried under snow (Haegeli et al, 2010). It has been previously noted that these users are typically motivated to go off-piste by the heightened personal sense of space they experience by going to harder to reach locations (Zweifel et al, 2012). Fredston et al (1995) have also noted that being part of a group dynamic also tends to make people become more confident, and as a result more likely to perceive risks as being lower than those who are on their own. Therefore groups of skiers or climbers may be at greater risk of avalanches than others.
Snow avalanches in the Carpathian Mountains were studied by using historical data from between 1940 and 2011. In that time frame the Făgăraş massif region incurred an accident rate similar to that of other European, and North American, mountainous regions (Schweizer and Jamieson, 2000): a total of seventy six fatalities and fifty injuries resulting from 48 avalanches.
Off-piste skiers were the group primarily affected by avalanches. A lack of knowledge of the causes and dynamics of the hazard gave them insufficient skills to be able to read the terrain in a way that increased their safety on the mountains. Many were found to have made bad navigational choices before they were either killed or injured by an avalanche. Similarly, climbers were also found to have had insufficient planning in advance of their trips, making them more vulnerable to causing and being injured or killed by avalanches. 66.7 percent of fatalities occurred where there were two or more people in the group.
Human factors do not work alone though, and natural circumstances also had a part to play in the likelihood of an avalanche causing death or injury. In the Carpathians, seventy percent of fatalities happened above 2300m in elevation, where snow depth was greater than at lower altitudes. Three quarters of the fatalities happened on slopes that had a gradient of between 30° and 40° and there was a much higher incidence of fatalities from avalanches on slopes that faced the moist, snow-laden air from the north and north west.
Researchers noted that in the early period of the study (1940-2004), there were far more fatalities and injuries (as a yearly average) than between 2004 and 2011. This is due, in part, to technical advancement in the equipment used in avalanche warning systems and greater understanding of the risk of avalanches amongst mountain rescue services and groups of recreational users such as skiers. It is likely to make more people aware of the potential risks associated with certain areas. In that earlier period there was a lack of knowledge, amongst both mountain tourists and workers in the region about the field conditions that made avalanches most likely to happen. Moreover, in the earlier period, mountain users were more likely to be using the region in large groups which, as stated earlier, appear to be more conducive to risk taking behaviour.
Combining the knowledge of potential avalanche conditions with an awareness of the types of human activities and behaviours that can trigger them, can reduce the risks involved with visiting and working in mountain areas. Since the National Administration of Meteorology was established in Romania in 2004-2005 there has been a marked reduction in the number of avalanche caused accidents in the Carpathian Mountains. The organisation, which monitors Romanian weather and climate data for a number of practical purposes, runs the Bâlea Work Nivology Laboratory in the Făgăraş massif itself. Monitoring fresh snowfall depths, along with wind, solar radiation and temperature (Schweizer et al, 2003) can allow laboratories such as this to model avalanche conditions and predict where they may occur, giving the region temporal and place specific guidance on high avalanche risk areas. The challenge now is to ensure that this information is reaching those groups that are most at risk, new and wider avalanche education programmes across the Carpathian Mountains will go some way towards reducing the death and fatality rates within these groups.
Fredston, J. Fesler, D. and Tremper, B. (1995) The human factor - lessons for avalanche education, Proceedings of the International Snow Science Workshop, Snowbird, UT, p473-486
Haegeli, P. Haider, W. Longland, M. and Beardmore, B. (2010) Amateur decision-making in avalanche terrain with and without a decision aid: a stated choice survey, Natural Hazards 52, p185-209
Maggioni, M. and Gruber, U. (2003) The influence of topographic parameters on avalanche release dimension and frequency, Cold Regions and Technology 37, p407-419
McClung, D. and Schaerer, P. (2006) The avalanche handbook, The Mountaineers, Seattle
Schweizer, J. and Jamieson, B. (2000) Field observation of skier-triggered avalanches, Proceedings International Snow Science Workshop, Big Sky, MT
Schweizer, J. Jamieson, B. and Schneebeli, M. (2003) Snow avalanche formation, Review of Geophysics 41, p2-25
Zweifel, B. Techel, F. and Bjork, C. (2012) Who is involved in avalanche accidents? Proceedings 2012 International Snow Science Workshop, Anchorage, Alaska, p234-239
Altitude
The height of a point on the land above sea level.
Aspect
The direction a slope of buildings faces in relation to wind and solar radiation.
Avalanche
A sudden, mass movement of snow down a mountain side.
Using polystyrene balls, students can recreate an avalanche on a pre-made plasticene model of a mountain side and ‘Lego’ model men. They can change the angle of the slope, change the side that receives the most snowfall and look at how the movement of people of the slope can cause avalanches. Students might also think about how to design a hard engineering management solution to the avalanches they create.
If the Romanian avalanches would have occurred in a different country, would the number of fatalities be the same? Students can complete a ‘think, pair, share’ exercise that looks at how development level might affect a country’s ability to cope with an avalanche.
Students can research the damage off-piste skiing can do to an environment in addition to triggering avalanches. Using this information, they can design a safety guide or poster advising people why staying to the main ski runs is a good idea for their own safety as well as the mountains themselves.
Janet’s original article
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