“Metropolisation” is a notion built through extension of the term “metropolis” (etymologically: the mother-city) in order to designate a process of qualitative transformation, both functional and morphologic, of very large cities.
Compared to the classical concentration process represented by cities in general, metropolisation is characterised by an increase of weight of the largest cities in the distribution of some functions, as well as by concentration of population in metropolitan areas. Contradicting some “forecasts” about decline of big cities, the metropolitan process relies on a networking of the mains agglomerations in which phenomena of connectivity tend to prevail over proximity relations.
Functional mutations of the largest cities generate re-compositions in urban morphology. Besides phenomena of urban sprawl, metropolisation implies, in numerous cases, the formation of a discontinuous and heterogeneous internal structure, which in periphery alternates areas of low density and secondary centralities (edge-cities, business centre, technopolis, etc). The combination of these processes leads to formation of ever more fragmented urban spaces, which question the models of distribution of city dwellers or of activities in relation to a single centre, such as those of W. Alonso or of C. Clark.
Interpretations diverge as to logics underlying the metropolisation process. Some like F. Moriconi-Ebrard see in metropolisation the logical outcome of a settlement system favouring concentration. This author proposes a metropolisation ratio verifying that for a same urbanisation ratio, the number of inhabitants living in the metropolises of a country strictly depends on its size. Whereas others like P. Veltz see there the territorial result of post-Fordist regulation modes combining uncertainty of economic situation and flexibility of the job market. Californian geographers such as A. Scott or M. Dear on their part insist on relations between functional and social mutations of very large cities and new forms of urban territoriality.