Modelling dynamic spatial processes: simulation of urban future scenarios through cellular automata

One of the most potentially useful applications of cellular automata (CA) from the point of view of spatial planning is their use in simulations of urban growth at local and regional level. Urban simulations are of particular interest to urban and regional planners since the future impacts of actions and policies are critically important. However, urban growth processes are usually difficult to simulate. This paper addresses from a theoretical point of view the question of why to use CA for urban scenario generation. In the first part of the paper, complexity as well as other properties of digital cities are analysed. The role of the urban land use allocation factors is also studied in order to propose a bottom-up approach which integrates the land use factors with the dynamic approach of the CA for modelling future urban land use scenarios. The second part of the paper presents an application of an urban CA in the city of Dublin. A simulation for 30 years has been produced using a CA software prototype. The results of the model have been tested by means of the fractal dimension and the comparison matrix methods. The simulation results are realistic and relatively accurate confirming the effectiveness of the proposed urban CA approach. (C) 2002 Elsevier Science B.V. All rights reserved.