Urban Ecology

Where the People Are

by Diane Boudreau

When you think about the environment, you probably think about plants and animals. Perhaps you also think about air and land and water. But what about people?

In urban areas, people have the biggest influence on the environment. They build houses and roads, plant gardens, drive cars, and throw away tons of garbage. People constantly reshape the landscape. Their activities affect the plants, animals, air, and water around them.

Patricia Gober is a social geographer at Arizona State University. She studies how people change the Earth’s surface. She is especially interested in Phoenix, and how it has grown and changed over the years.

During the past 100 years, the population of the Phoenix area grew tremendously. In 1900, only 20,457 people made their homes in Maricopa County. By 2000, that number had risen to 3,072,149.

All of those people need places to live, work, and play. Gober studies how people in Phoenix use the land for these activities. She also tries to predict how land will be used in the future.

In the early 1900s, most of the land in and around Phoenix was used for farming. By the end of the century, the area had become much more urban. A lot of the land is now used for houses, stores, and factories.

During the 1990s, the Phoenix area grew at lightning speed. Population scientists predict that it will continue to grow in the future. They look for trends. They study maps of where that population is distributed. For example, Phoenix is much more spread out than many other cities. Gober says this happened because Phoenix was developed very recently. People have cars. That means they don’t have to walk everywhere.

“If you look at the new parts of Washington D.C. or Atlanta or New York City, you’ll see a similar pattern. It’s largely due to the newness of development,” she says.

Cities also tend to develop along the routes of major transportation systems.

“The early streets of Phoenix followed some of the old trolley lines,” Gober explains. “The trolleys were built around 1890, and then were phased out in 1948.”

More recently, development has followed the major highways and roads. The population has spread out along the major freeways such as Interstates 10 and 17, and U.S. 60.

But how exactly do geographers predict where development will happen in the future?

“They start with population predictions made by experts at the Department of Economic Security,” explains Gober. “Geographers take those population numbers and fill it in where they think development will be.” They make assumptions based on what they know about development trends and about the area in question. Developed areas will probably get built up more. New development will happen in areas physically suited to it, and also along transportation lines.

Gober has some predictions of her own. She thinks that future development near in and around Phoenix will happen mostly in outlying areas like Apache Junction and Avondale.

“In the 1960s and 70s most of the growth in the Valley was in Phoenix itself. As the century unfolded you got much faster growth in the suburbs.” Gober thinks that both Phoenix and suburban growth will taper off in the future. “Most of the action is going to be in the outlying areas,” she says.

Scientists use these predictions. They try to figure out how development will alter the landscape and affect pollution, traffic, animal communities, and plant life. And that’s what ecology is all about.

Some people think that geography is just about memorizing countries or capital cities on a map. Gober says that geography involves much more, but those things are an important foundation to build on.

Learning facts about countries and cities are much like memorizing your multiplication tables. These facts are actually building blocks. They help students to learn about geographic processes.

“We geographers are pretty good at tackling environmental problems,” says Gober. “We know enough about both physical and social processes. Geography is a place where a lot of environmental issues are being addressed.”