Data Visualization

What is the data? 

This is avalanche fatality data in the US from the Colorado Avalanche Information Center. It reports the avalanche fatality date, location, travel mode, and death count. Starting in 1950, the data runs to the present and begins including written descriptions in the winter of 2017. This data is easily accessible to the public and serves as one of the measures avalanche institutes take to demonstrate the danger of backcountry travel. Its audience is both public and professional backcountry travelers.

 

The questions to ask from this data are, what is the most dangerous state in terms of avalanches? What is the most dangerous travel method? How have avalanche deaths changed over time?

 

Data Visualization Goal

These visualizations aim to show why avalanche deaths are increasing in the US. Trends in locations and travel methods may lead to some understanding of the increasing fatalities, such as an increase in deaths among skiers in Colorado could indicate that more Coloradoan skiers are entering the backcountry ill-prepared for avalanches.

 

Visualization #1

The simple timeline from this chart indicates that avalanche deaths are on the rise. A population trendline is added to show a possible cause. The focus of this chart is that avalanche deaths are increasing at a similar but more intense rate than the population. 

 

Variables

Variables included here are avalanche deaths, year, and population count. It should be noted that the population data used is only from the states that have had avalanche fatalities. Avalanche deaths can vary year by year, this is most often attributed to differences in the snowpack (the layering of snow by density levels which influences the likelihood of an avalanche).  

 

Questions Addressed

What are the trends in avalanche deaths across the US? How do these trends compare to the population? 

 

Why the line chart? 

The line chart quickly communicates change over time, and it also allows the viewer to understand both population and deaths quickly. Trends are most important with this visualization, which the line chart is effective at communicating. With the variance of avalanche deaths per year, it is best to show that, although some years may have fewer fatalities, deaths are still on the rise in the US. 

 

What do we learn?

Of course, we learn that avalanche deaths are on the rise, but we also see that they are at a greater variance and rate than the population rise. This indicates that population rise may be just one factor involved here. The visualization, in essence, is telling the viewer, “Yes, population rise may account for some avalanche deaths, but there is more going on here.” 

 

What do we still ask?

This chart is meant to encourage further questions, so there are many. Why are deaths increasing the way they are? There is no consistency among the deaths, and they do not increase at a steady rate like the population does. Are there areas that are more dangerous than others? Are these avalanche deaths mostly skiers, snowmobilers, or just residents? 

 

Visualization #2

A heatmap shows the most dangerous areas, by state. The filter on the side allows the user to discover what times of year are most dangerous. 

 

Variables

The variables are location and avalanche deaths with an included filter for the month of the year, and travel mode. The travel mode will be more important in later visualizations, but it explains what those who died in the avalanche were doing at the time of the slide (skier, snowmobiler, foot traveler). 

 

Questions Addressed

Where are avalanche deaths most common, and does the time of year affect that? Is any state particularly bad in terms of avalanche deaths? 

 

Why the heatmap? 

The heatmap shows the viewer the most extreme of the values. In this case, Colorado is proven to be the biggest culprit of avalanche deaths. Because heatmaps are not well-tailored for specific values, labels are included to allow for comparison. 

 

What do we learn?

We learn that Colorado is the most dangerous state overall in terms of avalanche deaths. Interestingly, Alaska becomes the top contender when the map is filtered to summer months. Other areas around the US have some deaths, but generally, the Rockies have the highest incidence rates. A simple conclusion to draw here is that where there is more snow, there are more avalanche deaths. More importantly, this puts avalanche deaths into a larger context of their region. The culture, lifestyle, and population of each state play a role in avalanche death counts. 

 

What do we still ask?

Now that we know which areas are on the rise, we ask why those areas are particularly dangerous. Does it have something to do with travel methods? Or is snowpack a greater indicator? 

 

Visualization #3

A treemap of avalanche deaths by travel method. 

 

Variables

Variables include: travel method and avalanche deaths. Both color and size are used to represent death counts because the human eye is terrible at perceiving volume alone. 

 

Questions Addressed

What travel methods are most dangerous? How do each state’s travel methods compare? 

 

Why the treemap? 

The treemap is simple on its own, but in combination with the rest of the visualizations in the dashboard, it becomes a powerful filter. The treemap allows the viewer to see both the trends over time and the dispersion of deaths by travel method. This leads to some strong conclusions. 

 

What do we learn?

There is not much consistency among travel methods in avalanche deaths state by state. Utah, for example, has suffered mostly backcountry skier avalanche deaths, while Montana has had mostly snowmobiler deaths and Alaska climber deaths. This reveals a story of increased avalanche deaths across the US that is variable by location. As interest in the backcountry increases, it is safe to assume that it will follow the trends shown in the treemap, i.e., the travel methods with the highest incidence rates will grow in avalanche deaths in their respective states. In the future years, we can expect more climbers to die in avalanches in Alaska, more snowmobilers in Montana, and more skiers in Utah. This is especially important for avalanche professionals, as they should focus their education on the travel modes with the most deaths in their area.

 

What do we still ask?

We have a window into the original question, “Why are avalanche deaths on the rise?” But we do not have the full answer. The visualizations demonstrate that each state has its own travel method of choice among avalanche fatalities, which could indicate that more people are participating in those activities. However, it is still not proven by the visualizations what role snowpack and weather play in this problem. 

 

The Story 

In the US, avalanche deaths are on the rise. An average of around 6 deaths in the 1950s has risen to an average of 30 deaths in recent years. While population growth may have an effect on this, death rates are increasing faster than population. In addition, avalanche deaths have incredible variance year by year, one winter may have 11 deaths and the next 30-another indication that there is more at play here. What is else causing this rise in avalanche deaths? What can we do to slow this increase? 

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Digging into avalanche fatality data, we can find the dispersion of avalanche deaths in the US is centered around the Rocky Mountain Range and Western US states. Colorado has the most deaths, which is expected as the state is infamous for having the most dangerous snowpack in the country. There are several conclusions that could be drawn from this. Because many Americans are immigrating to the Western US, perhaps there is a disparity of education and mindset among the new arrivals. Someone who has just moved to the mountains may not understand the danger of avalanches and could remain uneducated. The safest way to go into the backcountry is with knowledge and experience, an influx of backcountry recreators who have neither could lead to more fatalities.

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When filtering to the summer months, Alaska outpaces all other states in avalanche deaths. This leads to a rather obvious conclusion that Alaska is the only state with enough snow to have avalanches in the summer. Avalanche professionals in Alaska still need to understand this and continue their work throughout the year, rather than just during winter months.

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Alaskan summer avalanche deaths are most often climbers, which demonstrates the importance of including travel mode when we seek to answer our question. Breaking down the data, not only by location, but also by travel mode reveals insights. Backcountry skiing, snowmobiling, and climbing are the most common avalanche fatality methods of travel. Yet when we filter by state there is variance across the country as to travel mode in avalanche deaths. This is massively impactful, as the travel mode of backcountry recreators determines how they interact with the snow. Skiers tend to have slow and thoughtful progression, but they also traverse terrain traps, snowmobilers can move quickly through the backcountry and easily set off avalanches, and climbers are most exposed to icefall issues. Each of these groups has its own unique considerations to take into account when traveling through avalanche terrain. This variance demonstrates that avalanche education needs to be tailored to the local community. Montana has the highest incidences of snowmobiler deaths, so professionals should focus on snowmobile education, Alaska should focus on climbers, and so on. As to our question of why avalanche deaths are increasing, this chart could suggest that the most common travel modes in avalanche fatalities are increasing in popularity. In Utah, this is especially true, as backcountry skiing is growing incredibly popular. If, as suggested by the heatmap, more and more of these backcountry skiers are unfamiliar with the area and avalanches, this could be a strong aspect of the increase in avalanche deaths. 

 

Our initial questions (Why are avalanche deaths increasing in the US? How can we slow this increase?) are not entirely answered by this data, but we gain some understanding. As the Western US continues to grow, more people may unknowingly be putting themselves into avalanche paths. These states have historically had the most avalanche deaths, so avalanche professionals should prepare to increase outreach and education, especially for non-locals. The variance in travel mode across states’ avalanche deaths suggests that certain modes are more popular in some areas than others; avalanche professionals need to tailor their programs to their subsequent regions. Bringing all of this data together shows us that although avalanche deaths are on the rise, with careful consideration of travel mode, and backcountry experience of the area, avalanche deaths can be reduced.