A HUMAN PERSPECTIVE Around 4500 B.C. in Sumer, an ancient country in what today is Iraq, the city of Ur was settled. Eventually it grew to be home to as many as 34,000 people. Archaeologists believe that it was one of the first cities in the world. Within the city walls, a broad avenue led up to an immense temple with a roof that loomed 80 feet above the ground. Surrounding the temple were private homes and large open markets with shops on streets resembling those in cities of Southwest Asia today. Some people lived in two-story houses with balconies and even had clay-lined drains for waste disposal. A canal ran through the city from the river to a harbor built on its northern edge. This was not an overgrown village, but a real city.
In the centuries since, cities have grown so important that geographers have developed the field of urban geography—the study of how people use space in cities.
Growth of Urban Areas
Today, much of the population of the world lives in cities. Cities are not just areas with large populations—they are also centers of business and culture. Cities are often the birthplace of innovation and change in a society. Urban lifestyles are different from those of towns, villages, or rural areas. When geographers study urban areas, they consider location, land use, and functions of the city.
An urban area develops around a main city called the central city. The built-up area around the central city may include suburbs, which are political units touching the borders of the central city or touching other suburbs that touch the city. These suburbs are within commuting distance of the city. Some suburbs are mostly residential, while others have a whole range of urban activities.
Smaller cities or towns with open land between them and the central city are called exurbs. The city, its suburbs, and exurbs link together economically to form a functional area called a metropolitan area. A megalopolis is formed when several metropolitan areas grow together. An example of a megalopolis is the corridor in the northeastern United States including Boston, New York, Philadelphia, Baltimore, and Washington, D.C.
The dramatic rise in the number of cities and the changes in lifestyle that result is called urbanization. The trend to live in cities increased rapidly over the last two centuries. As more and more people moved into cities to find work, the cities and their surrounding areas grew. Today, some cities are enormous in physical area and have populations exceeding 10 million residents. As you can see above, cities are found on all continents except Antarctica.
Around the world, cities have certain geographic characteristics in common. Many cities are found in places that allow good transportation, such as on a river, lake, or coast. Others are found in places with easy access to natural resources. Sacramento, California, for instance, grew rapidly after gold was discovered in 1848 in north-central California. Because of their geographic advantages, cities serve as economic bases, attracting businesses and people to work in those businesses.
Cities are often places where goods are shifted from one form of transportation to another. For example, the city of Chicago, Illinois, is a transportation hub for goods produced in the upper Great Lakes states. Goods are sent by air, truck, or train to Chicago on Lake Michigan, then to the U.S. east coast and the rest of the world.
Cities may specialize in certain economic activities because of their location. For example, the city of Pittsburgh, Pennsylvania, which is located close to iron ore and coal sources, became a steel-producing center. The same is true for the city of Sheffield in England. Some urban areas may grow or expand because of economic activities located in the city. Brasilia, the capital of Brazil, has grown to 1.8 million people since 1960 because of all the government agencies and activities there. Cultural, educational, or military activities may also attract people to a specific location.
Land Use Patterns
Urban geographers also study land use, the activities that take place in cities. Basic land use patterns found in all cities are:
- residential, including single-family housing and apartment buildings
- industrial, areas reserved for manufacturing of goods
- commercial, used for private business and the buying and selling of retail products
The core of a city is almost always based on commercial activity. This area of the city is called the central business district (CBD). Business offices and stores are found in this part of the city. In some cities, very expensive housing may also be found there. Predictably, the value of the land in the CBD is very high. In fact, the land is so expensive that skyscrapers are often built to get the most value from the land.
As you move away from the CBD, other functions become more important. For example, residential housing begins to dominate land use. Generally, the farther you get from the CBD, the lower the value of the land. Lower land values may lead to less expensive housing. Tucked into these less expensive areas are industrial activities and retail areas, such as shopping centers, markets, or bazaars. However, the patterns for urban activities vary by culture and geography. Study the models below to learn more about urban land use patterns.
The Functions of Cities
The city is the center of a variety of functions. The map at the left shows a portion of the CBD of Chicago, Illinois. Notice that shopping, entertainment, and government services are located there. Large office buildings occupy much of the rest of the area shown.
Many cities also have educational and cultural activities such as libraries or museums located in the CBD. The Manhattan section of New York City, for example, is home to about 70 museums. Other functions of the city—such as manufacturing, wholesaling, residential, recreation, and a variety of religious and social services—may be located in other parts of the city.
Cities need a great deal of space to accomplish these functions, which makes good transportation absolutely essential. Major cities may have several forms of mass transit, such as bus systems, subways, or commuter trains, to move thousands of people to and from the areas of the city where the various functions take place. In some areas, freeway systems link people in the suburbs to the activities in the city. Geographers often study a city's transportation system to understand how well the city is fulfilling its functions. In the next section, you'll learn more about economic geography that takes place across the globe.