Saturday, September 5, 2009

Human-built landscape of the desert southwest

This summer, my family and I drove from Cheyenne, WY to Las Vegas, NV. We camped and took in the sights along the way.

This was my first time to visit Las Vegas, and I will have to say this is quite an explicit example of how humans have an impact on the geography of a place.

Las Vegas is located in the middle of the desert of the southwestern U.S. When entering the city from any direction you experience a dry, very hot, and desolate landscape. The climate here is classified as a Midlatitude Desert or BWk, according to the Modified Koppen Climate Classification System. This basically means it is a midlatitude desert, with low amounts of precipitation that mainly comes in the summer, and winter temperatures that can get fairly cool; even snow on occasion.

When you enter the city of Las Vegas itself, especially if you choose to venture along the famous "Strip" of casinos on Las Vegas Boulevard, you would never guess you were in the middle of the desert. The human-built landscape is something you have to see for yourself to really believe. It truly is the definition of a mirage - an image of paradise in the midst of a harsh and dry landscape.

How could humans have come to such a dry and desolate place and developed such an infrastructure as to attract millions of people to visit each year?

Hidden within the physical geography of this part of the Mojave Desert is an oasis underground, or a spring left over from a wetter climatic period for this area during pre-historic times. Because of this underground water supply, and more recently the diversion of the Colorado River, humans can create a habitable environment in an otherwise uninhabitable place.

And, people keep moving here. "For the past two decades, Las Vegas has been king of American urban growth. During one of its most notable growth spurts, in the early 1990s, more than six thousand people moved to the Las Vegas area each month" (Travis, 2007).

Can this area sustain this type of growth? Are the resources limited to a point where the surrounding landscape, and sensitive ecosystems are negatively affected? Go have a look at Lake Mead which is the result of the Colorado River being corralled by Hoover Dam in the canyons of the Black Mountains on the Nevada - Arizona border. This reservoir, largest in the U.S., provides water for irrigation in the desert areas of California and Arizona. The "bathtub" rings showing progressively dropping water levels in the human-made lake is an eerie reminder of human impact and the landscape; and, vice versa.


References:

Chronic, Halka (1993), Roadside Geology of Arizona. Missoula, MT: Mountain Press Publishing Company.

McKnight, Tom L., and Darrel Hess (2008), Physical Geography: A Landscape Appreciation. Upper Saddle River, NJ: Pearson Prentice Hall.

Travis, William R. (2007), New Geographies of the American West: Land Use and the Changing of Pattern of Place. Washington-Covelo-London: Island Press.