Megalopolis: an assay for the identification of the world urban mega-structures

Megalopolis: An Assay for the Identification of the World Urban Mega-structures ARELLANO, Blanca & ROCA, Josep [email protected], josep.roc[email protected] http://www.upc.edu/cpsv/ Lisbon, Portugal August 27th of 2015 55th Congress World Renaissance: Changing roles for people and places The 20th Century. Century of the urbanization World Renaissance: Changing roles for people and places From suburbanization (end of the XIX Century) to metropolitanization The worldwide spread of the automobile, improving communication infrastructures (road networks) and the endless growth of the peripheries (peri-urbanization) brought the generalization of urban sprawl The extension of the urbanization process to the developing world: a change in the geography of the urbanized world The oil crisis and changing production model of Fordism The counter-urbanization of Berry (1976), the desurbanization of Leo van der Berg (1982), the sprawling city of Indovina (1990), rurbanization, etc. A crisis of urbanization in the last quarter century? Desurbanization or …. World Renaissance: Changing roles for people and places … change in the geography of the urbanized world? World Renaissance: Changing roles for people and places The concept of megalopolis World Renaissance: Changing roles for people and places In 1915, in Cities in evolution, Geddes anticipated the concept of megalopolis: ‘The expectation is not absurd that the not very distant future will see practically one vast city-line along the Atlantic Coast for five hundred miles, and stretching back at many points; with a total of . . . many millions of population’ Geddes used the term conurbation to refer to the future city, but in a previous work, in 1904, he had already suggested the term megalopolis. Mumford was the first to use the term 'megalopolis' repeatedly. The 4th chapter of The Culture of Cities (1938), for example, is titled 'The rise and fall of Megalopolis' and he develops his thesis on the six stages of urban development: from the 'Eopolis' (village) to the 'polis' (association of villages) thereof to the 'Metropolis' (the capital city emerges), the 'megalopolis' ('the beginning of the decline'), the 'tyrannopolis' (the overexpansion of the urban system based on economic exploitation) and finally to the 'Nekropolis' (war and famine, city abandoned) Geddes Mumford The concept of Megalopolis World Renaissance: Changing roles for people and places Gottmann It is certainly Gottmann (1957,1961)to whom we owe the original work on the change of scale occurred in the urbanization. Gottmann in his book Megalopolis: The Urbanized Northeastern Seaboard of the United States, opened the systematic study of urban mega-regions. In the words of Gottmann: “In 1950,on the basis of the new census, the Bureau of the Census prepared a map, later published as an illustration to a booklet of statistics on State Economic Areas, which showed clearly the continuity of an area of "metropolitan" economy from a little north of Boston to a little south of Washington (…). This seemed to be a first statistical demonstration on the map of the existence of a continuous stretch of urban and suburban areas, the main NE-SW axis of which was about 600 miles long, and within the frame of which dwelt even in 1950 some 30 million people. (…)The supermetropolitan character of this vast area, the greatest such growth ever observed, called for a special name. We chose the word Megalopolis,of Greek origin” The concept of megalopolis: a complex and polemic concept World Renaissance: Changing roles for people and places Peter Hall •Northeastern Urban Complex (the east coast of the United States), •Great Lakes (Chicago, Detroit and Cleveland), •The Japanese Megalopolis (Tokyo, Yokohama, Nagoya and Osaka -Kobe), •The North-West European Megalopolis (the Randstat and the Rhine-Ruhr), •The area called England Megalopolis P. Hall recognized that only five superstructures on a global scale deserve the name of megacities: (1973) A physical and functional reality or an analysis tool? Phenomenon, all of them in the developed world Identification of Megalopolis World Renaissance: Changing roles for people and places Gottmann First approach: geographical and functional approach His approach was functional, qualitative, as juxtaposition of metropolitan areas (which came as defined by the Census functional areas of daily commuting residence / work). The notion of contact, coalescence and overlap (Clawson, 1971; Hall et al, 1973) functional metropolitan areas, is therefore the primary factor that allows identification of Megalopolis Definition of Megalopolis World Renaissance: Changing roles for people and places Second approach to the definition of megalopolis is the analysis of the spatial patterns of density of the human settlements. Morrill (2006), updated the work of Gottmann through the consideration of the Urbanized Areas of the USA Census Bureau, which shows the evolution of the megalopolis of Boston-Washington between 1950 and 2000. The work allows to see how the criterion density is not an efficient mechanism for defining megacities. Not only because of the discontinuity of densely populated areas, but the proliferation from the 70's of the phenomenon of ex-urban sprawl. Morrill Urbanized Areas in Boston-Washington Megalopolis (Morrill, 2006) Methodology World Renaissance: Changing roles for people and places This light intensity (64 of 256) allows a better identification of megalopolitan structures than alternative thresholds. For example, the intensity of light reflected by the ice at the poles is around 40, and very close to the light intensity of 38 is the reflection of the sandy deserts Source: Self prepared from NASA (2013). The analysis of these results, contrasted from the local knowledge has led to consider the threshold of 64 the best for the delimitation of the global megalopolis Methodology World Renaissance: Changing roles for people and places Source: Self prepared from NASA (2013). The contours of light (2012) with intensity equal to or greater than 64 have allowed to identify the lighted urban continuum, which have been aggregated into larger structures when there contiguity per vertex,or separation of one pixel at most,as can be seen in the image, where the agglomerations are shown, Boston (in white) and New York (in red). Boston (in white) and New York (in red) Methodology World Renaissance: Changing roles for people and places Finally, we’ve estimated the population of the continuing intensity contours of 64 or higher by overlapping the information of population (2008)of the LandScan database developed by the Oak Ridge National Laboratory, USA. LandScan allows to analyze the population structure of different environments in the urbanized planet, with a close approximation to the reality Source: Self prepared from LandScan (2008). Spatial distribution of the human population for Calcutta Methodology World Renaissance: Changing roles for people and places Overlapping the lighted contours with intensity of 64 and the LandScan database has allowed to calculate the population of the same area, identifying planetary megalopolis (2008-12). Source: Self prepared from LandScan (2008). Overlapping of the illuminated contours (64) and LandScan database for Calcutta Results World Renaissance: Changing roles for people and places The worldwide identification of 444,502 populated areas illuminated with sufficient intensity (64 on a scale of 256) for consideration of urban nature. 433 of these illuminated areas reach a population of over one million inhabitants, concentrating 2,537 million inhabitants, 37.8% of the population of the planet. 92 over 5 million represent the seeds of megalopolitan structures. And 30 structures, that we call proto-megas, exceed 15 million, reaching a population of 1,298,757,300 inhabitants, placing as strong candidates to be characterized as megalopolis. Following the work begun by Florida et al (2008), using the methodology of nighttime satellite images as a method for the delimitation of the megalopolis, our analysis allows: Population (intensity 64) Frequency Percentage Accumulate > 20.000.000 24 ,005 ,0 10.000.000 - 20.000.000 23 ,005 ,0 5.000.000 - 10.000.000 45 ,010 ,0 1.000.000 - 5.000.000 341 ,077 ,1 500.000/1.000.000 366 ,082 ,2 100.000 -500.000 2.323 ,523 ,7 50.000 -100.000 2.453 ,552 1,3 10.000 -50.000 12.325 2,773 4,0 5.000 -10.000 12.371 2,783 6,8 1.000 -5.000 57.357 12,904 19,7 100 -1.000 133.982 30,142 49,9 < 100 222.892 50,144 100 TOTAL 444.502 100 Results World Renaissance: Changing roles for people and places Source: Self prepared from LandScan (2008). 26 megacities with a population exceeding 20 million, concentrating 1,374,291,094 people in their environment. These megalopolis are distributed throughout the entire planet. Asia highlights the presence of 18 large agglomerations: 2 transnational (India-Pakistan and India-Bangladesh), 5 in India, 6 in China (5 in the continent and one in Taiwan), and 1 in Japan, Indonesia, Korea, Philippines and the Middle East. America (4 megalopolis) Europe (3 agglomerations) Africa (1 agglomeration) It demonstrates the global extent of the geography of the megalopolis. Only Oceania is free of such urban agglomerations. World Renaissance: Changing roles for people and places Megalopolis Population Area Indian-Pakistani 228.482.082 232.063,48 Java Island 97.818.609 44.643,43 Yang Tse Delta 83.378.386 61.635,58 Hokaido 82.274.578 44.337,03 Nil River 80.651.862 62.816,61 Beijing 78.835.106 63.641,85 Central Europe 59.742.557 95.982,48 Zhengzhou-Xian 53.328.310 40.309,40 Pearl River 52.078.700 27 .233,41 NY-Boston-Washington 49.685.899 85.170,18 South Korea 46.802.831 50.657,30 Calcutta 42.878.107 18.984,73 Uttar Pradesh 42.072.613 27.480,07 England 38.782.052 43.635,51 Mexico 35.554.545 30.371,74 Mumbai 32.900.124 15.288,50 Sao Paulo 30.959.310 23.402,76 Bangalore-Chennai 30.803.974 23.121,51 Med Orient 30.192.082 41.785,57 Coast of Fujian 30.040.766 15.221,38 North Italy 28.727.901 74.782,22 Ahmedabad-Silvassa 26.558.570 24.455,59 Manila 26.066.431 5.035,99 West Taiwan 22.047.022 15.146,67 South California 21.898.930 18.452,49 Dhaka 21.729.747 6.114,48 Source: Self prepared from LandScan (2008). Results World Renaissance: Changing roles for people and places Six megalopolis stand out for its extraordinary population size, with a population exceeding 75 million. These megalopolis are what might be called the premier league of world urban agglomerations. All of them located in Asia, with the exception of an African: the Indian-Pakistani, Java Island, Yangtze Delta, the island of Hokkaido, the Nile and Beijing agglomeration. No European or American megalopolis between these giants. Results World Renaissance: Changing roles for people and places Source: Self prepared from NASA-NOAA (2012) and LandScan (2008). The large conurbation of Central Europe, which stretches from Brussels Dutch Randstad, the Rhine-Ruhr, Strasbourg and Stuttgart. London to Cardiff and Bristol Birmingham, Sheffield, Manchester, Liverpool and Leeds, on the fourteenth place, The vast agglomeration of northern Italy, which It extends from Milan to Venice, in the twenty-first. The American megalopolis par excellence, the US Northeast (Boston - New York - Philadelphia - Baltimore - Washington), does not appear until the tenth place ranking, preceded by the two large Chinese structures ZhengzhouPearl River Xian. The rest of American megalopolis is reduced to other giant, the large urban agglomeration around Mexico City, which only appears in the fifteenth place, Sao Paulo - Santos , on seventeenth Los Angeles - San Diego - Tijuana (Southern California), which is the penultimate of the 26 megacities obtained in the present study Southern CA; World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places World Renaissance: Changing roles for people and places Thanks for your attention! World Renaissance: Changing roles for people and places ARELLANO, Blanca & ROCA, Josep [email protected], [email protected] http://www.upc.edu/cpsv/