Ideas clave y evolución en la ordenación territorial contemporánea. Evolución de los paradigmas disciplinares en base a los planes regionales de Nueva York (1929), Londres (1944), Copenhague (1947), París (1965), Barcelona (1966 y 2010), Holanda (2004), Bolonia (2004) y Marsella (2012)

Resumen

Large cities and urban regions need to be addressed, given their size, in a different scale, from a global and regional approach. This overall look, which creates real "city projects", is the topic chosen as the subject of this research: the Regional Planning. Although there are different works about the evolution of "regional planning" written by acclaimed auihors (Hall, Faludi, Ward, lndovina ... ), in general, they do not pursue a high level of detail or drawing. They trace the ideas, context and processes, but they do not delve into the instruments, the Regional Plans themselves. In order to fill this blank, the objective is to search how and why the key ideas behind the "big decisions" on the organization of the city change, basing on the study of different "plans" brought to reality. The line of argument rests upon the hypothesis that there is a common thread, a subtle connection in the way that cities are planned, traceable through time and space. The background ideas are inherited and revised frorn one case to another as a response to the challenges of the moment. For this evolution, the following Regional Plans are studied in depth: New York (1929), London (1944), Copenhagen (1947). París (1965), Barcelona (1965 and 2010), Bologna (2004), Holland (2006) and Marseille (2012). A reading of them shows that there are tour basic "common challenges" in their approach: rational land use, preservation of open space, distribution of centrality and optimization of mobility. The main contributions from each plan, to each of the above mentionaed key ideas are clearly stated, thus it is examined in detail how each evolves and the causes (internal and external) behind the innovations. The evolution of the plans shows that the concept of "rational land use" has undergone a great change: from a model of city expansion based on the urbanisation of new lands it has developped into one which furthers the reuse of those in existance. For decades, it was regarded as natural that cities grew colonizing large areas of the surrounding territory, but afterwards it was deemed more rational to reduce the consumption of land, avoid unjustified urbanization, concentrate developments and enhance urban recycling mechanisms. Regarding the preservation of open spaces, at first they were treated as reserves for growth and future needs, but now they are regarded as a final use of land"that forms the basic structure of territory. The environmental and biophysical matrix has become the basis for any decision making on the territory. This development reveals a profound change in the relationship between man and nature, now dominated by the pursuit of "environmental sustainability." The attitude of plans towards centrality has experienced profound changes, from searching the decentralization of cities that tended to be centripetal, it evolved into promete the recentralization of centrifugal urban regions. The economic, demographic and urban expansion has caused an increase in the number, type and distance in the relationships, creating a greater complexity. Such processes of dispersion and recentralization have given more relevance to many secondary centers and functional clusters, peripherical or internal, which has resulted in a much more polycentric territory. The optimization of mobility was previously focused in trying to resolve congestion on the basis of a great material effort to extend and densify the transport infrastructure, though it is now based on a more conservative approach that merely supplements, optimizes and integrates what already exists. Extending infrastructure was logical in order to break excessive mono-centrality and go with urban growth by meshing the periphery, but over time it has become evident that, versus a model of individual mobility (prívate cars), high capacity transport systems, especially railroads. were more economically and environmentally sustainable.