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 (creening the ikelihood of valanches on ackcountry ki 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 . 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.

中文翻译：

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SLABS：一种改进的概率方法，用于评估野外滑雪之旅的雪崩风险

野外滑雪者面临的主要危险是滑雪者自己引发的干板雪崩。在本文中，我们提出了一种新的概率方法来评估滑雪旅行时的雪崩风险：SLABS（筛选 ackcountry ki 旅行中雪崩的可能性）。 SLABS 方法是第一个完全统计推导的野外滑雪概率方法。我们使用了带有 GPS（全球定位系统）轨迹的野外滑雪之旅（57800 公里）的数据集以及过去 20 个冬季在瑞士记录的 1250 起事故的数据集。对这些数据拟合了具有区分事故和非事故的二项式链接的 GAM（广义相加模型）。作为预测变量，该模型使用与坡度角度的非线性关系以及与危险级别、海拔和坡向的线性关系。高风险工况和高风险工况的事故预防率分别为80%和60%。将 SLABS 方法与图形还原法 (GRM)、专业还原法 (PRM) 和定量还原法 (QRM) 进行比较表明，在给定的事故预防率下，它提供了更大的移动自由度。这是第一次对概率方法在事故预防和行动自由之间的权衡进行比较。由于 SLABS 方法不适合心算，因此在网站中实现。该网站每天评估整个阿尔卑斯山数千条野外旅行的雪崩风险，以帮助滑雪者计划下一次旅行。对于单个斜坡，SLABS 的风险评估提供了一个起点，必须用当地观察进行补充。