SELF-ORGANIZING CITIES

Self-organization, that is to say, the phenomena by which a system sel f-organizes its internal structure independent of external causes, is a fundamental property of open and complex systems. Such systems also exhibit phenomena of nonlinearity, instability, fractal structures and chaos - phenomena which are intimately related to the general sensati on of life and urbanism at the end of the 20th century. On the other h and, self-organization is a formal theory. It is, in fact, a general u mbrella for several theoretical approaches which, while they agree on general principles, differ in their treatment of such systems, in the emphasis they give to the various processes and properties and in the subject matter they refer to. In this paper I discuss some of those th eories and methodologies of self-organization which were applied to th e domain of cities and urbanism. The discussion proceeds under the tit le of seven categories of cities which are related to general theories or specific methodologies: dissipative cities, synergetic cities, cha otic cities, fractal cities, cellular automata cities, sandpile cities , and FAGS and IRN cities. The discussion of each category of cities s tarts with a shout introduction to the general principles of the appro ach and then elaborates on its self-organizing city. (C) 1997 Elsevier Science Ltd.