22 April 2013
An urban megaregion is a sub-continental scaled assemblage of dense urban settlements, edge cities, suburbs, exurbs, agricultural or pastoral lands, and wild lands. Often linear in form, megaregions can span hundreds of miles, and are connected by Interstate highways or motorways, main rail lines, and short to medium distance air routes. In opposition to the earlier concept and manifestation of regional urbanization identified as a megalopolis, in urban megaregions the urban cores are relatively indistinct and decentralized, urban development has multiple nodes, and the boundaries between urban, suburban, and exurban land covers are spatially complex and fuzzy. Commuting may be in several directions, including movement between edge cities and suburban transport nodes, between different suburban nodes, and between suburbs and old central cities. Furthermore, in the megaregions of the United States, the economic engine has shifted from industrial production to economies based on service, innovation, and consumption.
The megaregion has essentially replaced both the metropolis and the megalopolis as the predominant form of urbanization in many parts of the world. Baltimore is part of the US Northeastern Urban Megaregion, which runs from Richmond, Virginia, to Portland, Maine (Fig 6).
Figure 6. The Northeastern Urban Megaregion of the United States. Diameter of circles is proportional to individual metropolitan area population. From: Regional Plan Association, America 2050.
There are ten urban megaregions in the United States, and they also exist in Europe and Asia, for example (Fig. 7).
Figure 7. The urban megaregions in the United States, projected to 2050. From Regional Plan Association, America 2050.
The urban megaregion concept emphasizes the spatial extent, diffuse boundaries, and complex governance of urban areas today. Although it owes much to the megalopolis concept, the megaregion idea indicates that the concentration of power and wealth that characterized the core, industrial (e.g. Baltimore) or financial (e.g. New York) centers has dispersed.
Figure 8. The complexity of the Northeastern Urban Megaregion as a spatial mosaic. Densityof red color indicates the proportion of impervious land cover. Natural ecoregions are shown as the background map. University of Vermont, Spatial Analysis Lab.
Urban regions are composed of mosaics of intermingled, yet contrasting land covers and land uses (Fig. 8), so that interactions among those patches are more intense, and perhaps more conflicted than when urban areas were more clearly differentiated metropolises with large rural areas between them. The megaregion is a new form of urban organization, and its implications for social-ecological research and action are yet to be settled.
For more information:
§ Gottmann, J. 1961. Megalopolis: the urbanized northeastern seaboard of the United States. The Twentieth Century Fund, New York.
§ Lang, R. E. and D. Dhavale. 2005. Beyond megalopolis: exploring America's new "megalopolitan" geography. Metropolitan Institute at Virginia Tech, Blacksburg, VA.
§ Regional Plan Association. 2007. Northeast megaregion 2050: a common future. Regional Plan Association, New York.
§ Vicino, T. J., B. Hanlon, and J. R. Short. 2007. Megalopolis 50 years on: the transformation of a city region. International Journal of Urban and Regional Research 31:344-367.