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What Is This Indicator, and Why Is It Important?
This indicator reports the extent of urban and suburban lands,
both in acres and as a percentage of all land area in a region;
it also reports on the extent and composition of undeveloped
lands, such as wetlands, croplands, forest, or grassland and
shrubland, contained within urban and suburban areas.
About 75% of all Americans live on land that is urban or
suburban in character, which is less than 2% of the lower
48 states. Increases in urban/suburban area are generally
permanent and may affect the use and character of surrounding
lands (see the land use change indicator).
Describing the amount and composition of undeveloped lands
provides a coarse view of how intensely developed urban and
suburban lands are, which is related to the amount and type
of open space available to a regions residents (see
pubically accessible open space),
the extent of impervious surfaces (see total
impervious area), and the services provided by the natural
systems in urban and suburban areas (see natural
ecosystem services).
What Do the Data Show? In 1992, urban and
suburban areas occupied 32 million acres in the lower 48 states,
or 1.7% of total land area. Most of the land designated urban
or suburban is in the South and Midwest, but cities and suburbs
account for less than 2% of the land area in those regions.
In comparison, urban and suburban lands in the Northeast made
up over 5% of the landscape.
The South, Northeast, and West had nearly identical percentages
of undeveloped land within their urban and suburban areas
(about 22%), while the Midwest had less (17%). In the Northeast
and South, forests dominate these undeveloped areas; in the
Midwest, farmlands dominate, and in the West grasslands and
shrublands dominate.
Discussion The definition of urban and suburban
areas used here is fairly restrictive. It focuses on highly
urbanized areas and their surrounding suburbs, plus developed
outlying areas above a minimum size. It covers residential
areas, commercial and industrial areas, parks and golf courses,
and the like. It is not delineated on the basis of jurisdictional
boundaries, but rather on actual land cover as identified
using satellite data, and can be applied repeatedly over time.
Other programs (see technical note), such as those that tally
all developed lands, whether or not they are sufficiently
aggregated to be considered suburban, identify
more developed lands than are reported here.
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