1 Spatial Modelling of the Terrestrial Environment - Georeferencial

Editorial: Spatial Modelling of
Urban System Dynamics
Stuart L. Barr
With the world’s urban population expected to double between the years 2000 and 2020
(Harrison and Pearce, 2000), many urban areas will become increasingly dynamic environments,
experiencing growth that will result in changes in their social and economic
structure, spatial pattern of land use and their physical appearance. A consequence of such
growth will be that an increasing amount of the Earth’s natural and financial resources
will have to be directed towards urban areas, in order to supply the increased demand
for energy, food and water, as well as to provide the required housing stock and related
education and health services. Concerns over how to effectively manage such resources, in
order to minimize the negative impacts of urban growth, have increased the awareness that
sustainable urban planning policies need to be adopted that allow resources to be spatially
targeted and managed effectively.
Computational mathematical models of urban systems provide one potential mechanism
by which sounder theories of sustainable urban development may be developed as they
allow the likely effects of population growth on the physical, functional and socio-economic
structure of urban areas to be estimated (Wilson, 2000). Such models, whether coarse-scale
models of urban growth (Batty and Longley, 1994) or small-area level models of urban
activity and function, require a range of detailed geographically referenced information
for their initialization, calibration and validation. In many cases, particularly in developed
nations, such information is provided in the form of national censuses, which often provide
the most complete, consistent and objective information at a single point in time on the
socio-economic structure of urban areas (Wilson, 2000). A number of concerns have been
raised, however, in relation to the suitability of certain national censuses for studying and
modelling urban systems; these include, the long time period between censuses (often
Spatial Modelling of the Terrestrial Environment. Edited by R. Kelly, N. Drake, S. Barr.
C○ 2004 John Wiley & Sons, Ltd. ISBN: 0-470-84348-9.