11 June 2012


A metacity is a heterogeneous, dynamic urban region composed of multiple dense centers, intervening suburbs, embedded green spaces, and diffuse boundaries between traditional cities, suburbs, and exurbs.  Metacities are characterized as patch dynamic systems, in which neighborhoods, districts, boundaries, and the exchanges among patches change over time.  Governance in metacities is polycentric, that is, shared among different jurisdictions and with formal and informal social institutions. 

The metacity is a conceptual framework for understanding socio-ecological relationships and adaptive processes across different, specific neighborhood situations in all cities of whatever size and density, whether shrinking or growing.  It is a way of understanding any city as a patchy “system of systems,” and therefore related to metapopulation and metacommunity theory in ecology.  Metapopulations and metacommunities in ecology are spatially complex systems in which different elements – subpopulations and subcommunities, respectively -- are established or go extinct differentially.  Although the elements of any metasystem can exchange members or information periodically, each usually acts relatively independently of the others.  Differential connectivity, and differential risk of change are characteristics of “meta” systems in ecology, and these features apply to the metacity as well. 

A metacity can be conceived of as a mosaic of different landscapes.  Some of the landscape models represent the social and ecological processes, while other conceptions represent the choices that individuals and institutions make, and finally some landscapes represent the outcomes of both the processes and the choices.  Some of the outcomes are intentional and some are unintended and accidental (Figure 1).

Figure 1. The components of a metacity, conceived as landscapes defined by social and bioecological processes, by the choices that individuals and institutions make, and by the intentional and accidental outcomes of those choices.

Baltimore is an excellent example of a metacity.  It encompasses the traditional central business district that owes its density and concentration to the industrial and transportation infrastructure and economy of earlier centuries, as well as to the shift toward a service and knowledge based economy of the 21st century.  The city of Baltimore was designed to accommodate approximately 1.2 million inhabitants.  However, since 1950, the city has lost some 30% of its inhabitants while Baltimore County and other counties in the metropolitan area have grown.  As a result there are some 16,000  abandoned houses or vacant lots in the city.  

Figure 2. Vacant housing and lots in Baltimore City, from the harbor north.

Consequently, some of the streets that were formerly commercial magnets now have lost that function.  On a finer scale, the commercial buildings on corners in old rowhouse neighborhoods were often the first to be abandoned as the culture of mom-and-pop stores shifted first to strip malls, and later to big box stores.  Yet at the same time, suburban areas, including relatively “urban” areas such as Towson in Baltimore County, and Columbia, in Howard County, have become more dense and more active socially and economically.  Indeed, Carroll County and some areas in nearby Pennsylvania are now linked to the urban region of Baltimore. 

While dense rowhouse neighborhoods have thinned and provided opportunities for taking advantage of rational greenspace planning, brownfields resulting from the de-industrialization of Baltimore have also proliferated in Baltimore City and Baltimore County.  Some formerly industrial areas on the Inner Harbor have been converted to entertainment venues and upscale condos and apartments.  The area known as Harbor East, now boasting new high rise office buildings, luxury hotels, organic food markets, impressive wine merchants, and creative housewares merchants has emerged cheek by jowl to the Fells Point neighborhood, known as a freewheeling, gritty neighborhood since it was founded as Baltimore’s first deep water port serving merchant vessels and the worldly men who staffed them.

In Baltimore County, with its Urban-Rural Demarcation Line (URDL) established in the 1970s, patchy development has been enshrined in code.  The “URDL” is an extraordinarily effective planning tool, encompassing some 97% of the county’s residents.  The smart growth policy of Maryland plays out very effectively in this case.  BES research by Elena Irwin and colleagues at Ohio State University has shown that “leapfrogging” beyond Baltimore County’s URDL into adjacent Carroll County is not seen in statistical analysis.  The URDL restricts suburban development to areas along designated corridors served by public transportation, interstate highways, and sanitary sewers.  This has permitted Baltimore County to work with private land holders to consolidate management of large forest tracts to contribute to the Montreal Protocol goals of carbon sequestration, for example.  The patchiness of change in the Baltimore region epitomizes the metacity as a patchy, dynamic system of systems.

Figure 3. The Urban Rural Demarcation Line (URDL) in Baltimore County.  Baltimore City, a jurisdiction separate from the county, is also shown.

Why important:
The term metacity has been used before.  It was introduced by UN-HABITAT (United Nations 2006/7) to designate hypercities of over twenty million people.  Thus, the UN definition emphasizes size.  However, according to McGrath and Pickett (2011) the term should is not be limited to large urban agglomerations, but rather connoted to include the proliferation of new and dynamic forms of urbanization, each with distinct ecological and social attributes. These various urban configurations when combined with new digital sensing, communication and social networking technologies constitute a virtual meta-infrastructure, present in all sizes of city today. This new metacity has the potential to integrate new activist forms of ecological and urban design research and practice in making the transition from sanitary to sustainable city models globally.

For more information:
McGrath, B. P., V. Marshall, M. L. Cadenasso, J. M. Grove, S. T. A. Pickett, R. Plunz, and J. Towers, editors. 2007. Designing patch dynamics. Columbia University Graduate School of Architecture, Preservation and Planning, New York.
McGrath, B. and S. T. A. Pickett. 2011. The metacity: a conceptual framework for integrating ecology and urban design. Challenges 2: 2011:55-72.  http://www.mdpi.com/2078-1547/2/4/55/
Shane, D. G. 2011. Urban design since 1945 -- a global perspective. John Wiley & Sons, Ltd, Chichester UK.
United Nations. Urbanization: Mega & Metacities, New City States; UN-HABITAT: State of the World’s Cities 2006/7; United Nations: New York, NY, USA, 2006.

Contributed by: Brian P. McGrath, Parsons The New School for Design and Steward T.A. Pickett, Cary Institute of Ecosystem Studies.

1 comment:

  1. No matter how old you are, family history is important. While you might not think so at the time, as you get older there will be things you and your grandchildren will want to know. Most of us don't realise it until the older generations are gone and you can't replace first hand comments. Don't just put in about the good times, add in the harder times and how you overcame those trials. Another thing to remember is what caused the deaths of those you loved. There are many things that have been found to continue into future generations that knowing it runs in the family can be helped with now or possible in the future. prevention starts with knowing where to start. I wish someone had taken the time to write these things down for mew to be able to go back to. My Grandmother and my mother told us many stories of what things happened in their lives and about the people in their lives. I now wish someone had written those things down since both have passed now. But I never thought at that busy point in my life that I would one day want to remember all those things. So much family history is lost when the older generations are gone. Please pass it on to your family while you can. You can even just do it digitally so it can be accessed by family later on.Family pictures are something to cherish also. Just be sure to write down who is pictured in them, where they are taken and when. I have found family pictures that no one now even knows who is in them.