Definition – Urban agglomeration refers to the extended/contiguous built-up area of a city or town. This usually comprises a central city (municipality) and nearby towns and villages that have become linked into a continuous urban area. This often occurs as a result of “ribbon development” along main transport routes. The boundaries of an urban agglomeration do not necessarily reflect administrative boundaries or the entire region associated with the central city.
Relevance to SUMP – A SUMP should be prepared for the ‘functioning city’ (as defined by major commuter flows), which is likely to cover both the main urban area and surrounding peri-urban areas. In the majority of cases, the urban agglomeration and functioning city will extend beyond the administrative boundary of the central municipality, making collaboration with neighbouring public authorities necessary (see territorial integration).
Source: UN HABITAT, 2013