Monday, May 13, 2013

Las Vegas Sprawl: videos for my class

In Detroit blight and renewal, I promised a post showing videos of sprawl.  Here they are, two timelapse views from space of Las Vegas sprawling into the desert that I was insprired to look for when last Saturday's This Week @NASA included a segment on Landsat's Vegas Time-Lapse available on Google's Earth Engine.

My search made me realize that the Google Earth montage was not the first timelapse of Las Vegas's expansion.  To celebrate Landsat's 40th anniversary in 2012, NASA released a timelapse of false-color Landsat images of Las Vegas showing its growth beginning in 1972 and ending in 2010.

What Doesn't Stay in Vegas? Sprawl.

The companion news release explains what the video shows.
The city of Las Vegas, Nevada has undergone a massive growth spurt. An image series, created in honor of Landsat 5's twenty-eighth birthday, shows the city sprawling across the desert over time.

Data from the expansion of Las Vegas was compiled from the fleet of Landsat satellites, and is shown as a false-color time-lapse from years of data.

The large red areas are actually green space, mostly golf courses and city parks. The images become a lot sharper around 1984, when new instrument designs improved the ability to resolve smaller parcels of land.
That's pretty amazing, but it only shows Las Vegas reaching out to the west and south.  For a true-color version in which one can see the City of Sin growing in all directions, along with the shrinking of Lake Mead, here's a video explaining a montage from 1999 to 2011 that contains the last thirteen years of the images on the Google Earth Engine page.

Las Vegas Urban Expansion: Timelapse

Explore a global timelapse of our planet, constructed from Landsat satellite imagery. This timelapse from 1999 to 2011 captures the rapid growth of Las Vegas, Nevada, the fastest growing city in the United States over the past two decades. Each frame of the timelapse map is constructed from a year of Landsat satellite data, constituting annual 1.7-terapixel snapshot of the Earth at 30-meter resolution. The Landsat program, managed by the USGS, has been acquiring images of the Earth's surface since 1972. Landsat provides critical scientific information about our changing planet.
That the growth of Las Vegas coincides with the shrinking of Lake Mead is just that, a coincidence, but a striking one nonetheless.  What is not a coincidence is that Las Vegas stops expanding about 2008 with the start of the housing bust and recession.