For the near future, forecasts predict an uncontrolled growth of urbanization in the world, in which cities are fragmented and uneven systems in relation to fast evolving environmental, economic, and social phenomena. The traditional urban planning approach, essentially theoretical-predictive, adapts poorly to face future challenges. Hence, the need to rethink how to govern the transformations of cities, which can be described by models of urban metabolism. The city sensing has changed the way cities are explored and used. With the transition from digitalization to datafication, through the computational approach, georeferenced big data can be analysed and exploited by algorithms. They originate a generative computational urban planning process, which can achieve a higher quality of the project and provide cities with adaptive capability. This process exploits data provided by public administrations, companies, and citizens who take part in an inclusive and adaptive urban planning.
TopIntroduction
Nowadays about 55% of the world's population lives in urban areas, a percentage that is expected to increase. In 1990 there were just 10 megacities, classed as places with populations of 10 million or more. Globally, the number of megacities is expected to rise from 33 in 2018 to 43 in 2030. By 2030, the number of cities with one to 5 million inhabitants is expected to grow to 597 (United Nations Organization, 2018). In relation to what can be deduced from the data shown, cities represent one of the major problems to face in our contemporary era, both on the side of the environmental issues (energy consumption, pollution, etc.) and on the side of the economic and social ones (Figures 1, 2).
Some decades ago, Davis (1965) already wrote that urbanized societies, in which most people lived in crowded cities, were a new and basic step in man’s social evolution. It was clear that modern urbanization could be best understood in terms of its connection with economic growth and availability of resources. Moreover, in those days, there was hardly any widespread perception of the problems that urbanization could imply and only a few, non profit, international associations, such as the “Club of Rome”, founded in 1968, started to study solutions.
In relation to the increasing urbanization of contemporary society, Kevin Lynch’s last work, “Wasting away” (1990), is not optimistic. The satisfaction of voracious urban metabolism transforms incoming resources into waste that is not compatible with the environment. This pessimistic urban scenario of the near future is not very dissimilar from dystopic Orwell’s and Kafka’s visions earlier in the century. In fact, future scenarios foreshadow cities as extremely fragmented and uneven systems in relation to fast evolving environmental, economic, energy and social phenomena. According to Lynch, the basic assumption seemed, that far, to be that technology and advanced urban planning could solve every problem related to urban metabolism. Under this point of view the movies of the “Qatsi Trilogy”, an ecological eschatology, directed by Godfrey Reggio, Koyaanisquatsi (Coppola, 1982), Powaqqatsi (Coppola, 1988), Naquoyqatzi (Coppola, 2002), were visionary prophecies becoming little by little real in our time.
In his book, “Cities for a Small Planet”, Richard Rogers stated:
It is ironic that mankind’s habitat - our cities - are the major destroyer of the ecosystem and the greatest threat to mankind’s survival on the planet...While the need for cities and the inevitability of their continued growth will not diminish, city living per se need not lead to civilization’s self-destruction.
But he also stated:
I passionately believe that the arts of architecture and city planning could be evolved to provide crucial tools for safeguarding our future, creating cities that provide sustainable and civilising environments. … My cause for optimism is derived from three factors: the spread of ecological awareness, of communications technology and of automated production. All are contributory conditions for the development of an environmentally aware and socially responsible post-industrial urban culture (Rogers, 1998, pp.4-5).
If we observe the latest transformations that have taken place in our cities, we realize that probably, at some point in history, we have lost the ability to control the evolutionary processes of urban systems and the environment (Borga, 2013).
Otherwise, according to John Wilmoth, director of the UN's Population Division, progressive urbanization, if ruled, could prove a positive factor both for economy and quality of life. Furthermore, the concentration of the population in a large inhabited centre can help to minimize our environmental impact on the planet, optimizing the location of resources, provided that administrations develop policies and practices to prepare for a huge influx of people (Meredith, 2018).
Figure 1. World’s urbanization over the past 500 years (Ritchie & Roser, 2018)1
Figure 2. Left: World’s population growth since 1800. Source: UN. Adapted from source (Rosslyn, 2018); Right: World Urban and Rural Population projections from 2010 to 2100. Source: UN Department of Economics and Social Affairs – Population Division (2014)