Megaregion, Urban

Definition:  

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.

Examples:

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.

Why Important:

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.

Sanitary City

Definition: 

A sanitary city is an urban form developed to correct the ills and hazards of the industrial city (Fig. 1). 

Figure 1. Industrial city hazards stimulated the development of the sanitary city.

Sanitary cities segregate wastes and other hazards from residents.  Early sanitary cities accomplished this by collecting and piping sewage downstream (Fig. 2) or out to sea, by landfilling solid waste, by erecting tall smokestacks, and by employing single-use zoning.  As environmental awareness increased, the waste streams were treated more effectively.  Sanitary city solutions are engineered, management is based on separate sectors, such as water, traffic, health, etc., government is the active decision making and funding entity.  Furthermore, some aspects of environmental improvement assume that the demographic transition will play a role in improving people’s well being in the sanitary city.

Figure 2. The sanitary city depends on massive investment in infrastructure, originally designed to remove or segregate hazards from residents.  Here a large storm drain emerges from below ground to join a surface stream.

Examples: 

Sanitary cities are now common in countries where industrial or colonial wealth accumulated.  Baltimore is an example of a sanitary city, characterized by separate sanitary sewer and stormwater runoff collection systems.  Sanitary sewage is treated at least to the secondary level, in which biological digestion occurs at the end of the collection pipe.  Solid waste is collected, and an incinerator reduces the volume while generating electricity.  Recycling is a relatively recent addition to the sanitation regime.  In the United States, the Clean Water Act and the Clean Air Act have been important in reducing the impact of urban areas as pollution generators.

Why Important: 

The sanitary city has been an immense boon to human health and wellbeing in those nations and regions that have been able to implement and maintain the expensive technical infrastructure.  However, many cities or informal settlements have little access to basic sanitation, such as clean water delivery and collection and treatment of human and animal waste (Fig. 3).  In sanitary cities there is an increasing recognition that there are still improvements still to be made in environmental quality, and reduction of resource use, including energy, water, and building materials.  The increasing concern with environmental equity and quality of life and livelihood have been added to the mix by citizens and urban policy makers, who now call for cities to become more sustainable.  Hence, the sanitary city as a current state and ideal is contrasted with visions of the Sustainable City.

Figure 3. Informal development near Cape Town, South Africa.  Such shanty and favela settlements are common in rapidly growing cities around the world.  Many originally had no or rudimentary sanitary infrastructure, and such conditions persists in many.  Photo S.T.A. Pickett.

For more information:

·         Gandy, M. 2003. Concrete and clay: reworking nature in New York City. MIT Press, Cambridge.

·         Melosi, M.V. 2000. The sanitary city: urban infrastructure in America from Colonial times to the present. Johns Hopkins University Press, Baltimore.

·         Olson, S.H. 1997. Baltimore: the building of an American city. The Johns Hopkins University Press, Baltimore.