Modeling Suburbanization as an Evolutionary System Dynamic

摘要

The research undertaken investigates the applicability of Allen and Sanglier's dynamic model of urban system evolution to the process of suburbanization occurring in the post-World War II United States. The model, derived from principles of the theory of dissipative structures formulated by Ilya Prigogine, considers the urban system as open and far from equilibrium, thereby allowing a dynamic evolution which has the following properties. The structure of a system at any point in its development is historically contingent upon the sequence of structures it has exhibited in its past, and on the precise nature of random fluctuations which have acted to induce structural change. The joint action of chance and determinism influence a system's evolution through the complex interactions and feedback mechanisms embedded in its structure. The critical point at which these forces cause the system to undergo a structural change is called a bifurcation point. The model allows that the microdynamics of the system underlie its macrostate. This implies, therefore, the opportunity for individuals to influence the system's structure and for the possibility for creative system evolution to occur.The central question of the research was whether the processes of deconcentration of population and dispersal of employment from the central cities to the suburbs of large U.S. metropolises, with the resulting morphological shifts from mono- to polycentric urban forms, represent structural changes of the sort defined and modeled by Allen and Sanglier's adaptation of Prigogine's theory. The introduction of a calibration procedure, unspecified in previous applications of the model, provides a means whereby the calibration of the many system parameters can proceed in a systematic fashion, offering insight into the function of these parameters in the overall dynamic and their interactions with one another. Research results highlight the benefits of Allen and Sanglier's approach and areas inviting further investigation.