Arches on the Rise
It’s a fact. More people than ever are visiting America’s National Parks. In the past decade alone, there has been an increase of about 50 million annual visitors to National Park Service sites (national parks, monuments, and historic sites). Many factors have contributed to this including infrastructure upgrades and recent marking campaigns by the National Park Service to get more people interested in visiting these areas. It seems to be working.
I’ve visited the Moab, Utah area a few times in my lifetime. It really is a place full of wonder. Landscapes filled with red rocks and mountainous backgrounds make for beautiful photos and is some of the most unique scenery in the country. This area is also home to 3 National Park Service areas: Arches National Park, Canyonlands National Park, and Natural Bridges National Monument. To me, every time I’ve visited this area, it seems to busier than the time before. Parking lots have less space, campgrounds fill up earlier, and backcountry permits are more difficult to get. But is this actually true?
Almost national park areas in the US keep track of how many visitors pass through the park on a monthly basis. Unfortunately, they didn’t all start to collect this data at the same time, but what has been recorded is publicly accessible on the National Park Service website. Here, I’ll just be focusing on Arches National Park which has monthly visitor data from 1979 through the end of 2018 (at the time of writing). While visitation to National Park Service sites as a whole may be on the rise, that doesn’t necessarily mean that Arches itself has been getting busier. Let’s test that theory.
We can pick out the seasonal variation and the rolling average captures some of that increase in visitors, but to make it super clear:
Since 2010, the amount of annual visitors has increased by about 500,000 people.
This above chart confirms this. Overall, the busiest summers have been in the past few years (the lighter colors). Alright, so I’m not going crazy. Arches is actually getting busier. We can take this further, however. With the rather sharp increases in visitation at Arches NP over the the course of the past decade, it would be useful for both visitors and park officials to know how this trend may continue.
To predict future visitation rates, I’ll be using linear regression. After calculating a variable to keeps track of how many months from 1979 a date is, I used this and the month to create a model that produced an r-squared value of 0.862. Not too bad. I used that model to the predict what visitor patterns may look like for 2019 through 2025.
When I plot the projected data and the actual data alongside each other, we can see that the predicted data is capturing the recent upward trend, but not the massive seasonal variability that also occurs. To visualize this, we can look at the Residuals chart below.
sm.tsa.seasonal_decompose(visitor_series).plot()
The above model attempts to capture seasonal variation, and it goes a relatively good job around 1990–2009. On the far ends of the timeline, residuals are high. This means that the gap between winter visitor counts and summer visitor counts is extremely wide compared to the average. So, I filtered out all data before 2010 and created a new model.
This model produced an r-squared value of 0.974. It captures the peak summer visitor counts much better than the previous model, but seems to overestimate the amount of visitors in the wintertime. The ideal model sits somewhere in the middle of these two models. It may be possible to add more features to the model as well such as campground availability and weather data.
Either way, the second model demonstrates that the busy season in Arches National Park is only going to become much, much busier and park officials will almost certainly need to take measures to account for this.
Conclusion
In the case of Arches, the current trend of more and more Americans going to see their national parks is going to continue. It is also justifiable to say that these trends indicate future visitation to the greater Moab area as well. Moab is a small town driven by tourism. For the economy, more tourism is good. For the surrounding natural resources and landscapes, this could pose a big problem.
