Geoscience Reference
In-Depth Information
4.
The Industrial Revolution in the 19th century allowed
human population to grow rapidly because mechaniza-
tion, increased sanitation, and developments in medi-
cine led to longer and better lives. In 1800 the global
population was about 1 billion, whereas in 1900 it was
approximately 1.7 billion.
Las Vegas is located within the low-latitude desert climate
(
BWh
) in the Köppen system, which is extremely arid. In other
words, hundreds of thousands of people have recently moved
into a region where it rarely rains and natural water supplies
are scarce. Although the current economic downturn has slowed
population growth in the area, the effect at this time has been
essentially to stabilize the number of people rather than to cause
a steep decline.
The competing pressures of high population and the poten-
tial lack of freshwater pose challenging questions for the current
and future residents of Las Vegas, as well as other large cities in
the Southwest such as Phoenix and Tucson, Arizona, and Albu-
querque, New Mexico. Are these cities sustainable places that
can continue to grow, or will they one day decline if and when
water supplies give out? Regardless of the ultimate outcome,
to understand the issues and appreciate the various solutions
proposed require a deep understanding of physical geography.
As you probably know, Las Vegas is a world-famous re-
sort city that draws millions of tourists every year. Located in
the southern part of Nevada in Clark County (Figure 20.5), the
metropolitan area lies within the Las Vegas Valley, which is part
of the Basin and Range physiographic province discussed in
Chapter 13. The Las Vegas Valley is bordered to the immediate
5.
Global population is now about 6.8 billion and is pro-
jected to reach approximately 9 billion by 2050. This
large number of people is having huge impacts on the
natural environment.
Case 1: Water Issues in the Arid
American Southwest
The first case study examines water use in the American South-
west. It focuses on the Las Vegas metropolitan area, which has
been one of the fastest-growing urban zones in America since
the mid-20th century. According to the U.S. Census Bureau, the
population of the Las Vegas metropolitan area increased from
about 1.4 million in 2000 to about 2 million today. Ironically,
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(a)
Figure 20.5 Las Vegas, Nevada.
(a) Las Vegas is located
within Clark County in the southern part of Nevada. (b) Skyline
of Las Vegas. Las Vegas is a world-famous resort city that lies
within the arid Mojave Desert.
(b)
