Image Processing Reference
In-Depth Information
Chapter Summary
Urban is a place-based characteristic that describes the degree to which the
lives of a spatial concentration of people are organized around nonagricultural
activities. The urbanness of a place is determined based on a range of elements
encompassing population size and density, social and economic organization,
and the transformation of the natural and agriculture environments into a
built environment. Because of the spatial and temporal variability of such
elements, the degree of urbanness varies across space (and through time),
suggesting that urban and rural are, in fact, ends of a continuum, rather than
representing a dichotomy. The idea of an urban-rural continuum or gradient
lends itself to the development of indices to help describe how urban (or how
rural) a place is at a given point of time. This chapter has introduced you to
one of such indices, an urban index that combines census and survey data
(to capture aspects of the social environment) with data from remotely sensed
imagery (to capture aspects of the built environment). Focusing mainly on
the latter part of the equation, this chapter has discussed several issues to
be considered in using remote sensing to define the urbanness of a place,
including: (1) the spatial unit of analysis to be used (pixel versus zonal units);
(2) the variables to be combined in the index (composition and configuration
of the built environment); and (3) how the variables will be combined to
create an index (spectral mixture analysis and landscape metrics).
LEARNING ACTIVITIES
Internet Resources
•
Explore the changing nature of urbanness
The Timeline of New Urbanism
http://www.nutimeline.net/.
Features several
way to search key events in the history of new urban since the nineteenth
century.
USGS Urban Dynamics Program.
http://landcover.usgs.gov/urban/intro.asp.
Features temporal maps and data
resources, animations, articles, and timelines for selected metropolitan regions
in the United States.
