The Structure and Form of Urban Settlements - Remote Sensing of Urban and Suburban Areas - page 17

Table 2.1 Types of sprawl
Type High density Low density

Compact contiguous Circular or radial using mass transit Possible but rare?

Linear strip corridor Corridor development around mass

transit

Ribbon development along
radial routes

Polynucleated nodal Urban nodes divided by green belts Metro regions with new towns

Scattered/discontiguous Possible but rare? Metro regions with edge cities

alternatives to the compact ideal of urban development. In practice sprawling forms
can be considered to lie along a continuum from fairly compact to completely dis-
persed developments.
A variety of urban forms can be described using a typology based on two continu-
ous dimensions, which here are made discrete for explanatory purposes: settlement
density (high and low) and physical configuration (ranging from contiguous and
compact to scattered and discontiguous). This classification system suggests the eight
idealized types of sprawl which are presented in Table 2.1 .
Galster et al. ( 2001 ) have also classified the physical forms associated with
urban sprawl into types (Fig. 2.1 ) and which need to be viewed in the context of the
typology presented in Table 2.1 . This classification also accommodates consider-
ations of physical configuration and density. This method classifies patterns of
urban sprawl according to eight components: density, continuity, concentration,
clustering, centrality, nuclearity, land use mix and proximity . These measures are
demonstrably useful to identify the major dimensions of sprawl. At the more com-
pact end of the scale, the traditional pattern of suburban growth has been identified
as sprawl. Suburban growth is defined as the contiguous expansion of existing
development from a central core. Scattered or leapfrog development lies at the
other end of the spectrum (Harvey and Clark 1965 ). The leapfrog form character-
istically exhibits discontinuous development some way from a historic central core,
with the intervening areas interspersed with vacant land. This is generally described
as sprawl in the literature, although less extreme forms are also included under the
term. Other forms that are classified as sprawl include compact growth around a
number of smaller centers (polynucleated growth), and linear urban forms, such as
strip developments, along major transport routes.
Indeed a vocabulary of different varieties of sprawl is fast
emerging due to the fact that growth everywhere seems to be
somewhat uncoordinated particularly on the periphery of the
city (Hayden 2004 ). Sprawl in fact exists in very different
forms which range from highly clustered centers - edge cities
- in low density landscapes to the kinds of edgeless cities that
exist where cities grow together into mega-poles of the kind
that are characteristic of western Europe and even eastern
China. The morphology of these structures ranges from rather distinct edges and
peripheries to somewhat more blurred or fuzzy perimeters and these various differences

the various
forms for urban
sprawl pose a
challenge for
urban remote
sensing