Image Processing Reference
In-Depth Information
6.1
Introduction
Growing interest in urban systems as ecological entities provides rich opportunities
for remote sensing research and application. The wide
array of environmental variables within the city and in
surrounding landscapes calls for a means of identifying
and quantifying land cover types in a systematic and
repetitive manner. To the extent this can be done simply
and effectively through satellite-borne digital multispec-
tral remote sensing, several positive results may follow:
(a) environmental comparisons may be established
between cities of the world, (b) dynamic changes of
environmental patterns within cities can be mapped and
quantified, (c) environmental change consequent to urban expansion into adjacent
landscapes can be mapped and quantified, (d) various science and engineering
models relating to energy, moisture, and atmospheric quality dependent on land
cover can be applied, (e) population, demographic, and other human dimensions
of urban places may be estimated, and (f) urban and environmental planning can
be enriched by effective, dynamic application of remote sensing.
Given that urban land cover features are so complex in terms of size, shape, and
physical composition, and so mixed in terms of complex patterns, the challenge to
remote sensing is great. In recent years improved spatial
and radiometric resolution from satellite-borne sensors
has given a boost to mapping in greater detail. However,
the challenge of coping with the great variety of land
cover types remains (see former discussions in Chapters 4
and 5). In primitive settlements of the developing world,
the problem is relatively simple as building materials are
less varied. However, in cities of the developed world, an
infinite variety of cover materials may be present. Thus
the problem of standardizing identification, characteriza-
tion, quantification, and mapping is a significant matter. If
a model for such standardization can be obtained then a
global “comparative anatomy for cities” can be accom-
plished. Further, dynamic changes and environmental
impact over time can be measured and mapped.
In an effort to produce such standardization for urban/peri-urban ecosystems the
V-I-S (Vegetation-Impervious surface-Soil) model was introduced (Ridd
1995
).
This chapter deals with the theory supporting the model, and some applications of
the model in different urban settings.
satellite remote
sensing provides a
standardized means
of identifying and
quantifying land
cover types in a
systematic and
repetitive manner
the complexity of
urban morphology
in contemporary
cities and the
great variety of
urban materials
and land cover
types introduce
significant
challenges to
urban remote
sensing analysis
