Image Processing Reference
In-Depth Information
Fig. 6.3
Placement of the eight sites in spectral space, in a visible/near infrared plot
region, soil gives way to vegetation. Desert shrub lands (7) typically are devoid of
impervious surface, and are dominated by exposed soil although some desert shrub
areas may rise to 60% or more in vegetation cover. Here again variations are docu-
mented by the model. A primitive village in arid land (8) usually has little vegetation,
and impervious surfaces may be limited to rooftops.
6.2.1
Relationship to Urban Spatial Models
Models of urban form have typically been based on human activities and land use
patterns (Burgess
1925
; Hoyt
1939
; Harris and Ullman
1945
). Chapter 2 in this
topic continues that tradition with more-or-less concentric rings or zones outward
from a city core or center to suburbs and beyond to a hinterland. Parameters such
as commuting patterns, population density, and employment are used to define the
character of the rings outward from the city center. These rings or zones are conve-
nient for discussing V-I-S composition because of our general familiarity with the
association of observable land cover with various human factors. However, the V-I-S
model is prepared to quantify land cover patterns regardless of variations in rings,
zones, radial sectors, or whatever land use or socioeconomic patterns exist.
To simplify and generalize for the present purpose, a
typical transition from a commercial core outward might
be through a sequence of residential zones of decreasing
housing density to the outlying hinterland or peri-urban
environment adjacent to the built-up urbanized area
(Fig.
6.4
). Residences nearest the city center tend to be
high density apartment districts with relatively little space
for vegetation. In a series of “concentric rings” outward,
high density residential areas grade into medium and low
spatial variations
in urban land use
patterns can be
quantified by the
V-I-S model in
terms of variations
in the V-I-S
compositions
