Backcountry Skiers Research Articles

Dating of avalanches in Pirin mountains in Bulgaria by tree-ring analysis of Pinus peuce and Pinus heldriechii trees

Snow avalanches are among the most important disturbances in mountain ecosystems. The effects of avalanches on the endemic Pinus heldreichii and Pinus peuce forests in the Pirin Mountains in Bulgaria are poorly understood. These forests are among the few remaining old-growth forests with preserved natural dynamics in Europe. However, the ongoing development of tourist infrastructure at the borders of some of the best-preserved Pinus heldreichii and Pinus peuce forests close to Bansko ski resort leads to increased tourist pressure. Many backcountry skiers and snowboarders venture beyond the resort boundaries, practicing their activities in these forests and avalanche tracks and couloirs within them. The objective of our study was to collect tree-ring cores from Pinus peuce and Pinus heldreichii trees affected by avalanches and verify the specific types of damages and tree responses characteristic for the species and region. Then using the collected data, we aimed at reconstructing the years in which specific areas were affected by avalanches and in this way obtain data on the magnitude of larger events. Our study shows that large magnitude avalanches (LMA) in the vicinity of Bansko ski resort in the Pirin Mountains in Bulgaria occurred dozens of times in the 20th century. On average the period between LMAs ranged between 9 and 20 years with the shortest period between two such events in one couloir being 2 years. Avalanches affected forests high on the couloir banks and left traces in the tree rings related to the mechanical impact that snow avalanches had on the surviving trees. In the studied tree-ring cores of Pinus peuce and Pinus heldreichii the most informative types of responses were sharp growth suppressions, including missing rings, followed by reaction wood and in less cases visible scars and callus tissue. Our data for frequent large avalanches shows that is necessary to address the avalanche risk with high priority especially for the Palashica couloir, which directly threatens the lower parts of the ski runs as well as other facilities in Bansko ski resort.

SLABS: An improved probabilistic method to assess the avalanche risk on backcountry ski tours

The main danger to which backcountry skiers are exposed are dry slab avalanches triggered by skiers themselves. In this paper we present a new probabilistic method to assess the avalanche risk when planning a ski tour: SLABS (Screening the Likelihood of Avalanches on Backcountry Ski tours). The SLABS method is the first fully statistically derived probabilistic method for backcountry skiing. We used a data set with GPS (Global Positioning System) tracks of backcountry ski tours (57.8 thousand km) and a data set of 1250 accidents recorded in Switzerland during the last 20 winter seasons. A GAM (Generalised Additive Model) with binomial link discriminating between accidents and non-accidents was fitted to these data. As predictors the model uses a non-linear relation with the slope angle, and a linear relation with the danger level, the elevation and the aspect. Conditions with elevated and high risk were defined such that the accident prevention rate is 80% and 60%, respectively. A comparison of the SLABS method with the Graphical Reduction Method (GRM), the Professional Reduction Method (PRM) and the Quantitative Reduction Method (QRM) shows that it offers more freedom of movement for a given accident prevention rate. It is the first time that probabilistic methods are compared in terms of their trade-off between accident prevention and freedom of movement. Because the SLABS method is not suited for mental arithmetic it is implemented in the website www.skitourenguru.ch. This website evaluates on a daily basis the avalanche risk along thousands of backcountry tours throughout the Alps to help skiers plan their next tour. For a single slope the risk assessment of SLABS provides a starting point that has to be supplemented with local observations.

History of Avalanches in the Eastern Spanish Pyrenees

Avalanches have caused injuries and deaths in mountain areas throughout history. We have examined the historical effects of avalanches on communities in the eastern Spanish Pyrenees. Surviving written records began in the year 1444 when an avalanche destroyed the village of Gessa. Many other avalanchessince then have destroyed houses and other buildings and have caused injuries and deaths. In the 20th and 21st centuries, many villages evolved from agrarian areas to destinations for winter sports. The first known deaths during winter recreation likely occurred in 1930. Because of avalanche mitigation efforts, including relocating settlements, physical barriers, avalanche control measures, effortsto increase avalanche awareness, and avalanche warnings, avalanches now seldom affect inhabited areas in the eastern Spanish Pyrenees. Avalanche injuries and fatalities are now mainly limited to backcountry skiers and others traveling out of bounds near avalanche-controlled ski resorts.

Avalanche Airbag Usage and Risk Attitudes of Backcountry Skiers and Snowboarders in the American West.

Backcountry skiers and snowboarders are increasingly using avalanche airbags to improve safety. New safety devices can cause risk compensation, the concept in which users take more risks given the larger safety margin provided by the device. This may limit overall benefits. We sought to elucidate attitudes toward risk-taking behaviors and risk compensation in backcountry users relating to avalanche airbags. A convenience sample of 144 backcountry skiers and snowboarders was surveyed after a backcountry tour in the Wasatch Mountains of Utah and the Tetons of Wyoming during the winter 2020-21 season. Demographic and experiential data were compared with risk propensity scores and attitudes toward risk compensation. Respondents were stratified into high-, medium-, and low-risk groupings based on risk propensity scores and whether an airbag was carried. Thirty-two (22%) respondents carried an airbag. Airbag users were more likely to endorse risk compensation behavior, ski terrain over 30 degrees, and fall into the high-risk cohort. The high-risk cohort was also more likely to endorse risk compensation behavior than medium- and low-risk individuals. Risk compensation was more prevalent in 2 groups: 1) those carrying an airbag and 2) those falling within the high-risk cohort. Given the prevalence of avalanche airbags, risk compensation should be considered alongside other human factors in avalanche safety and education so that users can mitigate these effects. Although risk compensation appears to be occurring, the magnitude of this effect remains unknown and likely does not obviate the safety benefits of the airbag altogether.

Effectiveness and Use of Avalanche Airbags in Mortality Reduction Among Winter Recreationists

Introduction:The number of backcountry skiers and snowboarder surged in the last years, especially during the COVID-19 pandemic, as ski resorts shut down. Inevitably, this led to an increase in avalanche-related injuries and death. As avalanche rescue device, avalanche airbags are increasingly becoming part of the standard winter mountaineering equipment.Method:This study provides a review of available data and an updated perspective on avalanche airbags, discussing their function and efficacy to reduce mortality and their limitations.Results:Causes of death in individuals caught by avalanches are multiple. Airbags seem to reduce mortality by decreasing chances of critical burial, the most determining risk factor. However, there is scarcity of reliable scientific research on the topic, and the way in which airbags reduce mortality and to what extent is still debated. Several elements seem to influence airbags efficacy, and their use still yields several limitations linked to manufacturing, proper use, users education, and risk compensation.Conclusion:Avalanche airbags seem to be an important tool in reducing mortality in backcountry expeditions. However, more research and standardized data collection is needed to fill the knowledge gap, mountain communities should promote adequate education of winter-recreationists on how to prevent and react to an avalanche, and on the correct use of airbags in combination with already available tools such as transceivers, probes and shovels, and manufacturing companies should ensure higher efficacy of the survival avalanche equipment for better prevention of burial, asphyxia, and trauma.

Effectiveness and use of avalanche airbags in mortality reduction among winter-recreationists.

The number of backcountry skiers and snowboarder surged in the last years, especially during the COVID-19 pandemic, as ski resorts shut down. Inevitably, this led to an increase in avalanche-related injuries and death. As avalanche rescue device, avalanche airbags are increasingly becoming part of the standard winter mountaineering equipment. This study provides a review of the available data and an updated perspective on avalanche airbags, discussing their function and efficacy to reduce mortality and their limitations. Causes of death in individuals caught by avalanches are multiple. Airbags seem to reduce mortality by decreasing the chances of critical burial, the most determining risk factor. However, there is a scarcity of reliable scientific research on the topic, and the way in which airbags reduce mortality and to what extent is still debated. Several elements seem to influence airbags efficacy, and their use still yields several limitations linked to manufacturing, proper use, users education and risk compensation. Avalanche airbags seem to be an important tool in reducing mortality in the backcountry expeditions. However, more research and standardized data collection are needed to fill the knowledge gap, and mountain communities should promote adequate education of winter-recreationists on how to prevent and react to an avalanche and on the correct use of airbags in combination with already available tools such as transceivers, probes and shovels; and manufacturing companies should ensure higher efficacy of the survival avalanche equipment for better prevention of burial, asphyxia and trauma.

Perceptions Among Backcountry Skiers During the COVID-19 Pandemic: Avalanche Safety and Backcountry Habits of New and Established Skiers.

IntroductionThe coronavirus disease 2019 (COVID-19) pandemic impacted the ski industry worldwide by closing or limiting access to ski resorts. Subsequently, anecdotal reports of increased backcountry use emerged in the press, with concerns of inexperienced skiers causing or having problems in the backcountry. This study attempted to quantify this and identify motivations for new backcountry skiers.MethodsSelf-identified backcountry skiers and snowboarders (aged ≥18 y) in the United States and Canada completed an anonymous 29-question online survey distributed by regional avalanche centers, education providers, and skiing organizations (n=4792). Respondents were stratified by backcountry experience, defining “newcomers” who began backcountry skiing from 2019 to 2021, coincident with the COVID-19 pandemic. Percentages of ski days spent in the backcountry were compared before and during the COVID-19 pandemic using paired t-tests and across cohorts using repeated-measures analysis of variance. Avalanche education was compared using unpaired χ2 tests.ResultsOf established skiers, 81% noticed more people in the backcountry and 27% reported increasing their own use. Participants reported spending 17% (95% CI, 15.8–17.9) more of their days in the backcountry during the COVID-19 pandemic, with newcomers increasing their time spent by 36% and established skiers increasing their time spent by 13% (P<0.0001). Of newcomers, 27% cited the COVID-19 pandemic as motivation to enter the backcountry and 24% lacked formal avalanche education, which is significantly higher than the 14% of established skiers (P<0.0001).ConclusionsInfluenced by factors related to COVID-19, reported backcountry use increased during the pandemic. Newcomers had a lower level of avalanche education and less confidence in evaluating terrain. Because 80% of participants were recruited from avalanche safety or education websites, this likely underestimates skiers lacking avalanche awareness or education and is further limited by the nature of online surveys.

Avalanche Preparedness and Accident Analysis Among Backcountry Skier, Sidecountry, and Snowmobile Fatalities in the United States: 2009 to 2019.

While avalanche fatalities have remained relatively steady per year, data suggest a possible increase in sidecountry use and snowmobile fatalities. Limited information is known regarding the accident details and preparedness among different groups of backcountry users including snowmobiles, sidecountry, and backcountry skiers, and what specific factors could contribute to their fatalities. Avalanche fatality reports covering all US states posted by the Colorado Avalanche Information Center available online for 10 seasons (2009-2010 through 2018-2019 seasons) were analyzed for group size, specific equipment carried, burial depth, burial time, and other details. Only reports in the 3 following categories were included in the analysis: backcountry ski/snowboard, sidecountry ski/snowboard, and snowmobile/snowbike. These aspects were compared among the 3 tourer types using statistical analyses (ANOVA). Two hundred and five fatalities were analyzed (n=32 sidecountry, n=91 skier/snowboard, n=82 snowmobile/snowbike). Using 2 preparedness scores, the ski/snowboard group had the greatest distribution of high scores when evaluated by equipment carried and group size, with significant differences per group (P<0.01). Of the fatalities that were buried, burial time was related to the tourer group (P=0.04), with the ski/snowboard group having the highest proportion of burials <15 min. Burial depth was significantly different among the 3 tourer groups, with snowmobiles buried the deepest on average (P<0.01). Despite limited data available on fatalities, an analysis of preparedness suggests that backcountry skiers and snowboarders are more prepared for avalanche accidents compared to snowmobiles and sidecountry users when evaluated by equipment carried and group size.

The Impact of Avalanche Education on Risk Perception, Confidence, and Decision-Making among Backcountry Skiers

With the burgeoning popularity of winter backcountry leisure, there has been an increased interest in implementing education to prevent avalanche related accidents. Yet little research has explored whether avalanche education actually improves avalanche risk awareness. The current study examined why participants enrolled in avalanche education, what they learned, and whether participation led to changes in risk perceptions, risk perception confidence, and decision-making. Backcountry skiers and snowboarders enrolled in an introductory avalanche course in Montana (N = 184, 47.28% female) completed surveys before and after the course that included randomized photos of regional avalanche terrain. Multi-level models demonstrated that participants became more conservative in their risk perceptions and their stated willingness to ski uncertain terrain between pre- and post-test. Perception confidence increased, with larger gains for women, novices, and risk averse skiers. The results provide preliminary evidence that avalanche education may impact risk perceptions and provide useful hands-on skills for winter backcountry recreationalists.

Should I judge safety or danger? Perceived risk depends on the question frame.

Linguistic polarity is a natural characteristic of judgments: Is that situation safe/dangerous? How difficult/easy was the task? Is that politician honest/dishonest? Across six studies (N = 1599), we tested how the qualitative frame of the question eliciting a risk judgment influenced risk perception and behavior intention. Using a series of hypothetical scenarios of skiing in avalanche terrain, experienced backcountry skiers judged either how safe or how dangerous each scenario was and indicated whether they would ski the scenario. Phrasing risk judgments in terms of safety elicited lower judged safety values, which in turn resulted in a lower likelihood of intending to ski the slope. The frame "safe" did not evoke a more positive assessment than the frame "danger" as might be expected under a valence-consistent or communication-driven framing effect. This seemingly paradoxical direction of the effect suggests that the question frame directed attention in a way that guided selective information sampling. Uncertainty was not required for this effect as it was observed when judging objectively safe, uncertain, and dangerous scenarios. These findings advance our theoretical understanding of framing effects and can inform the development of practices that harness question framing for applied risk perception and communication. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

On the correlation between the forecast avalanche danger and avalanche risk taken by backcountry skiers in Switzerland

Rule-based decision frameworks are widely recommended to estimate the avalanche risk while planning a ski tour. However, these frameworks were developed relying primarily on accident data and usually did not consider backcountry travel data. Hence, they are not risk-based. Here, we address this gap and calculate the risk taken during backcountry touring in avalanche terrain and correlate it to the expected avalanche conditions as described in a public avalanche forecast. For this, we rely on 784 reported avalanche accidents and more than 2.1 million movement points in potential avalanche terrain, based on GPS tracks recorded in Switzerland for 14 winter seasons. Combining this data with the respective avalanche forecast, we show that risk increases fourfold from danger level 1-Low to 2-Moderate, and from 2-Moderate to 3-Considerable. Furthermore, at 2-Moderate and 3-Considerable, in the critical elevations and aspects specified in the avalanche forecast, the risk is nearly six times higher compared to locations outside this, so-called, core zone. For danger level 1-Low, where the Swiss avalanche forecast does not provide any information about the critical elevations and aspects, we derived a risk-based core zone. Within this core zone too, the risk is about six times higher than outside. These findings suggest an adaption of the rule-based decision frameworks to reflect the observed risk better. The proposed framework considers the strong influence of the elevation and reduces the effect of the aspect, compared to former decision frameworks. We emphasize that this new decision framework cannot replace on-site risk assessment. However, it allows backcountry users to come closer to the goal of achieving a minimum of avalanche risk while allowing a maximum of freedom of movement.

Liking and perceived safety across judgments of distinct instances of a category of activity

Prior research on the affect heuristic demonstrated that the more a person likes an object or activity, the safer and more valuable it is judged to be. That relation was found when judging stimuli at the categorical level (e.g., nuclear power, airplane travel, heart surgery). Yet risk judgments and decisions usually pertain to specific instances of an object or activity rather than their categorical representations. We examined whether the relation between liking and perceived safety holds across multiple judgments of specific instances of an activity distinguished by contextual information. In four studies (N = 372), participants with domain-specific experience (backcountry skiers) completed multicue risk judgments under high uncertainty (judging the avalanche risk in backcountry skiing scenarios) and reported their degree of liking the scenarios. We demonstrate that the positive relation between liking and perceived safety holds across multiple judgments of specific instances of the activity. Furthermore, the liking-perceived safety relation (i.e., judging liked slopes to be safe, judging disliked slopes to be unsafe) held among backcountry skiers who like the activity and consider it safe at the categorical level. We discuss these findings from the perspective that contextual valence and perceived risk can dynamically diverge from categorical valence and perceived risk when perceiving specific instances of that category. These findings have implications for research on attitudes toward risk in extreme sports and other high-risk activities. Although it has been proposed that participants in extreme sports like risk and the thrill it provides, we found that backcountry skiers exhibit a healthy positive relation between liking and perceived safety when judging specific instances of skiing in avalanche terrain.

Using Citizen Science to Document Terrain Use and Decision-Making of Backcountry Users

Avalanches represent the primary risk of death to backcountry skiers and snowmobilers in North American and European alpine countries. The best strategy for evading dangerous snowpack conditions that may result in an avalanche event requires skiers and snowmobilers to avoid or mitigate their use of hazardous terrain. Therefore, understanding terrain use is critical to understanding the causes of avalanche accidents. Secondary, post-event examination of accident data is inadequate for this understanding, and the logistical costs of user intercept surveys are problematic. Learning more about the behaviors and practices skiers and snowmobilers use to avoid avalanche fatalities or near misses is the primary concern of the avalanche education and research community. However, the topographical data required for analysis of skier and snowmobiler behavior with respect to terrain use is beyond the capacity of most backcountry skiers to provide via traditional surveys. This paper presents the use of a novel combination of user surveys and Global Positioning System (GPS) tracking to collect detailed terrain-use data from recreationists who voluntarily engage with researchers via active participation in citizen science research projects. We describe the methodology for these observations and present why they represent an effective approach to understand avalanche accidents.

Using time lapse photography to document terrain preferences of backcountry skiers

Travel in avalanche terrain requires considered and careful selection of appropriate terrain to reduce exposure to avalanche danger. In many parts of the world, recreational backcountry skiers in avalanche terrain are aided by a regional avalanche forecast. The overall aim of an avalanche forecast is for users to adjust their terrain choices in response to the avalanche danger rating and avalanche problem, thereby reducing their risk of an avalanche involvement. In this paper we present a novel passive observation technique to assess how lift assisted backcountry skiers adjust their terrain use in response to the avalanche danger rating.This paper develops and demonstrates a method to record the terrain metrics of all skiers on an avalanche-prone backcountry slope. Using a remote time-lapse camera focused on a high skier-use backcountry slope, we anonymously recorded the descent route of skiers in ten-second increments. Using 31,966 images over 13 days and 7499 skier point locations, skier locations were digitized from the images, then transformed onto a geo-referenced digital elevation model (DEM) such that terrain metrics could be extracted for each anonymous skier location.When these location points are compared to simultaneous GPS measurements, the horizontal accuracy was estimated to be within a 49-m horizontal accuracy, with a 95% confidence interval. Analysis of the terrain metrics for each skier point compared slope, profile curvature (downslope), and plan curvature (cross slope) over days with different forecasted avalanche danger ratings. This statistical analysis was qualitatively supported by a review of the spatial patterns of the terrain choices on these days. Furthermore, we used this technique to estimate group size, and found a surprising number of solo skiers, even on Considerable avalanche danger days. By remotely photographing all skiers on a slope, the data collected provides a large and diverse data set of the terrain preferences of backcountry skiers under varying avalanche conditions, with limited bias. These results have implications for avalanche education by enhancing our understanding of specific terrain management skills by backcountry skiers.

The value of remote Arctic destinations for backcountry skiers

ABSTRACTChoosing remote Arctic areas as a destination for practising backcountry skiing is a relatively new phenomenon. The Arctic’s unique attraction for skiers can be attributed to its wilderness and amazing natural beauty, the unlikelihood of external rescue and the necessity to rely on a guide as well as other participants, which strengthens bonds within the group and heightens the experience. Near the Arctic Circle, conditions are difficult and there are greater risks than in other mountains. This study aims to investigate the experiences, motivations and values that participants gain from such excursions. Drawing on observations, a survey of participants of expeditions (n = 46) to East Greenland and West Fjords, Iceland (purposive sampling) and interviews with operators (n = 4) this study gives insight into the values remote Arctic areas provide to skiers. Three groups of values can be distinguished: those connected with nature (the beauty, wilderness and remoteness of the area), a second group connected with ski touring (unspoiled powder, independent trails) and finally values related to the presence of and bonds with other participants. Value is created by experiences. The results highlight strong push motivational factors among participants. This also explains their propensity to pay a high price (300€ per day on average) for an expedition.

Avalanche Safety Practices Among Backcountry Skiers and Snowboarders in Jackson Hole in 2016

Carrying standard safety gear (beacon, probe, and shovel), planning a route of descent, and recreating with companions can help to mitigate the risk of injury or death resulting from avalanches in the backcountry. The goal of this study was to identify factors associated with performance of these safety practices. A convenience sample of backcountry skiers and snowboarders was surveyed in 2016 at the backcountry gates of Jackson Hole Mountain Resort. Each participant was surveyed on characteristics including skill level, sex, age, prior avalanche education, and residency in the Jackson Hole area. Safety practices were also measured against avalanche hazard forecasts. Correlations were assessed using Fisher's exact testing. A total of 334 participants were surveyed. Factors associated with carrying avalanche safety gear included higher expertise, being a resident of the Jackson Hole area, and prior avalanche education. Factors associated with having a planned route of descent included higher expertise and being a resident of the Jackson Hole area. Factors associated with recreating with companions included younger age and lower expertise. Sex had no association with any of the surveyed safety practices. Participants were less likely to carry avalanche safety gear on low avalanche hazard days. Certain individual characteristics of backcountry skiers and snowboarders are associated with increased frequency of adherence to recommended safety practices. These findings suggest that particular categories of backcountry recreationists may benefit from further avalanche safety education. The results of this study could help direct future educational efforts among backcountry recreationists.

Combining environmental values with perceptions of infrastructure development ─ The Management Options Matrix

Population growth and competing recreational, environmental, and economic pressures increasingly threaten urban-proximate protected areas throughout the world. In the Wasatch Mountains of Northern Utah, proposed ski resort development on and near protected areas has elicited strong resistance from environmental groups and human-powered backcountry recreationists, such as backcountry skiers, for over thirty years. Recent collaborative planning processes (i.e., Mountain Accord) have been unable to reconcile the interests of backcountry recreationists and the local ski industry. This study examined the environmental values and perceptions of one stakeholder group, backcountry skiers, toward infrastructure development in order to test a new research and management tool, the Management Options Matrix. Results indicate relationships between backcountry skiers’ environmental values and development perceptions that can help inform future collaborative planning processes in the Wasatch. These findings have implications for managers in Northern Utah, as well as public land managers working in other park and protected area contexts that experience high visitation and conflict over limited resources. Management implications●Managers seek tools that help categorize specific constituent group’s values and perceptions, as well as interpret how they may inform management solutions.●The paper presents five different groups of management options addressed to the specific environmental values of the target group and development themes present in the study population.●This approach allowed the organization of protected area users’ comments into defensible categories that provide managers with population-specific information to craft durable, collaborative solutions.

Overconfident people are more exposed to “black swan” events: a case study of avalanche risk

Overconfidence is a well-established bias in which someone's subjective confidence in their own judgments is systematically greater than their objective accuracy. There is abundant anecdotal evidence that overconfident people increase their exposure to risk. In this paper, we test whether overconfident people underestimate the probability of incurring an avalanche accident. An avalanche accident is a typical event because it has a low probability of occurring but has potential dramatic consequences. To test whether the overconfidence bias affects the decision of backcountry skiers to go on a ski trip under different levels of avalanche risk, we measured individual cognitive traits and then used a random effect logit model to measure their effects on the probability to take the tour, by controlling for other observable characteristics of the respondent. We show that 1) overconfidence is widespread even in our sample and 2) practitioners who are more prone to overestimate their knowledge are also more likely to take the risk associated with a ski trip exposed to avalanche danger. This suggests that overconfident people are more exposed to black swan events.

Comparison of logistic regressions and snowfall intensity–duration threshold as forecasting tools for direct-action snow avalanches in the Presidential Range, New Hampshire, USA

Snow avalanches are an important natural hazard for backcountry skiers and alpinists in the Presidential Range (New Hampshire, United States). Over the past 20 years, over 72 people were involved in avalanche accidents. Direct-action avalanches resulting from recent snowfall dominate the avalanche regime of this region. Given this peculiarity, avalanche activity should be influenced by the intensity and duration of snowfalls. This study compares logistic regressions (LR) and a novel approach based on snowfall intensity–duration (ID) thresholds to analyse the weather patterns favourable to the triggering of snow avalanches. LR models suggest that 72-h solid precipitation, 24-h liquid precipitation, 72-h average daily maximum temperature and 72-h average winds peed are the best predictors of avalanche activity. The accuracy of the snowfall ID threshold to predict snow avalanches was similar to the accuracy of rainfall ID thresholds to identify landslide activity. However, a Monte Carlo cross-validation procedure suggests that the LR model is more accurate and more robust in predicting avalanche activity, since they allow the inclusion of more meteorological predictors. Finally, we discuss the relevance of this novel approach and the need for replicate studies in similar, direct-action avalanche-dominated contexts.

Spatial and temporal analysis of fatal off-piste and backcountry avalanche accidents in Austria with a comparison of results in Switzerland, France, Italy and the US

Abstract. In this article we analyzed spatial and temporal patterns of fatal Austrian avalanche accidents caused by backcountry and off-piste skiers and snowboarders within the winter periods 1967/1968–2015/2016. The data were based on reports of the Austrian Board for Alpine Safety and reports of the information services of the federal states. Using the date and the location of the recorded avalanche accidents, we were able to carry out spatial and temporal analyses applying generalized additive models and Markov random-field models. As a result of the trend analysis we noticed an increasing trend of backcountry and off-piste avalanche fatalities within the winter periods 1967/1968–2015/2016 (although slightly decreasing in recent years), which is in contradiction to the widespread opinion in Austria that the number of fatalities is constant over time. Additionally, we compared Austrian results with results of Switzerland, France, Italy and the US based on data from the International Commission of Alpine Rescue (ICAR). As a result of the spatial analysis, we noticed two hot spots of avalanche fatalities (Arlberg–Silvretta and Sölden). Because of the increasing trend and the rather narrow regional distribution of the fatalities, initiatives aimed at preventing avalanche accidents were highly recommended.