Section #2: Urban Uses of Land

Urbanization the movement of people from rural areas to cities main reason to move = finding more plentiful & better jobs as urban populations have grown many small towns have grown together to form larger urban areas – think suburban sprawl – they’re called metropolitan areas

Growth of the Washington D.C.-Baltimore Area Over the Years

The Urban Crisis urban areas run into trouble when they grow a rapid increase in population can lead to traffic jams, substandard housing, increases in air & water pollution a city’s infrastructure – all the things that a society does for public use – cannot handle the crowds

Infrastructure roads railroads bridges canals water mains sewers power/gas lines fire & police stations schools libraries hospitals

Urban Sprawl rapid expansion of a city into the countryside around the city results in the building of suburbs on land that was once used for food production people in the suburbs often commute to work in the city – this increases pollution from car exhaust in 2000, more Americans lived in the suburbs than in cities & rural areas combined each year suburbs spread over 2.5 million acres of land in the U.S.

Substandard Living Conditions on the Outskirts of Hong Kong

Suburbs Taking Over the Farmland

Development of Marginal Lands most cities were originally built where there is little room for expansion as these cities grew, the suburbs were built on land that is poorly suited for building examples include Los Angeles & Mexico City that were built in basins, the expansions have moved into the surrounding mountains where the slopes are prone to erosion & landslides this is often true along coastlines as well

Marginal Land Along the California Coastline

Other Impacts of Urbanization Creation of a HEAT ISLAND cities both generate & trap more heat, causing the temperatures in & around a city to rise this heat is produced by the infrastructure that makes a city run roads & buildings both absorb & retain heat longer then vegetation

Heat Island over Atlanta, GA

Heat Islands scientists are beginning to see that heat islands can affect local weather patterns as the hot air rises over a city, it cools & condenses producing rain clouds & an increase in rainfall this can then lead to flooding in city because there is very little area that can soak up the extra water planting trees for shade & installing reflective rooftops can help

Land-Use Planning determining in advance how land will be used is beneficial these plans can map out where homes, businesses, & factories will be built which areas will be protected for recreation best locations for shopping malls, sewers, electrical & water lines placement of roads, highways, & mass transit

Urban Planning often controversial & complex federal government requires developers to prepare detailed reports assessing the environmental impact of projects the public then has a right to comment on these reports developers, city governments, local businesses, & citizens often disagree, especially when environmentally sensitive areas are in question

Intelligent Design the sophisticated tools of today use GIS (geographic information systems) to help with land-use planning GIS is a computerized system for storing, manipulating, & viewing geographic data planners can try different combinations of data, such as the location of sewer lines, road, & parks, & then overlay these maps on top of each other

Each image is a different GIS layer with specific info about Seattle, WA

Transportation if you compare American to European cities, you’ll notice that most American cities were designed to be traveled with automobiles most American cities were constructed after the automobile was invented & are almost impossible to travel without a vehicle most European cities were built before cars & consist of narrow, compact roads

Transportation mass transit systems were designed to get people where they needed to go by moving lots of people at one time with buses & trains these save energy, reduce highway congestion, reduce air pollution, & limit the loss of land to the construction of roads & parking lots if mass transit systems are not available, carpooling is another alternative

Mass Transit

Open Space land within an urban area that is set aside for scenic & recreational enjoyment include parks, public gardens, bicycle & hiking trails often referred to as GREENBELTS if they are left in their natural condition open spaces are environmentally beneficial & provide several valuable functions

Open Space plants in these open spaces absorb carbon dioxide, produce oxygen, & filter out pollutants from the air & water keep cities cooler in the summer reduce drainage problems by absorbing more of the rainwater runoff from areas covered with buildings, asphalt, & concrete (less flooding) provides a place of exercise & relaxation for city dwellers