In ESPON DB, cities can first be described as morphological agglomerations characterized by high density and/or by contiguous urban fabric. Although this approach is not the best-suited to capture a city as a "system of relationships" and to follow the urban sprawl process, cities as urban agglomerations still remain very useful and complementary to Fynctionnal Urban Areas (FUA). They are especially relevant when analyzing the planning of infrastructure systems, the provision and coordination of local and the study of land-use patterns. They also enable apprehension of the urban hierarchy as a whole and not only for the largest cities, as there is no FUA delineation for smaller citis.
Three european databases result from this conceptual approach of cities as morphological objects and can be consulted in the ESPON platform; the Urban Morphological Zones (UMZ) from the Environmental Agency, the Morphological Urban Areas (MUA) which are the core of the Functional Urban Areas from IGEAT, and the Cities which are part of the Larger Urban Zones from Eurostat/OECD/urban audit >JRC. They all result from a similar top-down process, but each of them follows different criteria and construction rules, that are summed up in Figure 2.5 and presented in the following sections".
The UrbanMorphological Zones (UMZ) database was created by the European Environment Agecny (EEA) in 2002. The EEA used the CORINE Land Cover database and quite automatic methods for delineating these agglomerations. The main criterion used is a maximal distance one. UMZ are composed by continously built-up areas, with a maximum spacing of 200m. These are relate to several modes of Land Cover in the CORINE nomenclature: the category "urban fabric" (continuous or discontinuous), but also "industrial commercial units", "green urabn areas", certain forest spaces, port areas; airports, sports and leisure facilities, and road and rail networks (for more details about the construction rules, see Milego 2007).
In the ESPON Database portal, four types of modifications were brought to the matest version of UMZ that can be downloaded on EEA website (F3v0), in order to make them more operational for urban studies:
A name was associated to each UMZ, in order to create a semantic link between these morphological patches and the territory. This step was processed by using an automated method and an expert assessment (Bretagnolle et al., 2010). It has also allowed validating the relevance of UMZ database as compared to national agglomeration databases (Guerois et al., 2012).
A selection of over 10000 inhabitants was decided, in order to be able to study small and medium sized cities.
Thepopulation of each UMZ in 2000 (year of reference) was added by using the last version (v.5) of the population density grid constructed by the European Commission research centre (Gallego, 2010).
UMZ delineations can also be adjusted to LAU2 geometry by the means of a UMZ-LAU2 dictionary. The method used for developing such a dictionary is explained in the First Interim Report online (M4D_FIR_revised) and a Technical report is planned for December 2013.
The UMZ database that is available in the ESPON DB thus comprises about 4300 cities covering 29 countries (EU28 and Liechtenstein).
The following spreadsheet contains the complete description of the UMZ classification:
Composed of about 4304 units over the ESPON area, a map representing this nomenclature is shown in Figure 2.6.
For the needs of the study area filters of the ESPON Database Portal Search Query interface, an additional
sheet has been added to the UMZ nomenclature definition xls file:
The MUA (Morphologic Urban Areas) database has been created in 2007 and updated in 2011 by IGEAT (Institut de Gestion de l'Environnement et d'Aménagement du Territoire, Unversité Libre de Bruxelles) in order to associate morphological cores to the FUA_Igeat (Functional Urban Areas) database. The delineation of MUA for the year of reference 2001 is mainly based on the selection of the most densely populated municipalities, along with some secondary rules:
The main rule depends on minimal density criterion. Specifically, it is based on the selection of municipalities (LAU2) whose popultion density is over 650 inhab./km2. A MUA is composed by a municipalities of high density, "as well as the municipalities not reaching the threshold but enclosed by the others" (IGEAT et al., 2007).
A second rule lies on a minimal population criterion (20 000 inhabitants). It is especially used to select municipalities characterized by a "true urban character", but that "are not reaching the level of 650 inhab./km2, due to some specificities of the delimitation of the municipality" (for instance a very large municipal territory) (IGEAT et al. 2007). All the municiplaities over 20 000 inhabitants are thus also considered as MUA "whenever they have a clear concentrated morphological core". Only the MUA characterized by high densities and population over 20000 inhabitants can be considered as urban cores of FUA.
In some large conurbations, contiguous LAU2 of high density were split into several MUA when different nodes could be clearly distinguished from a morphological point of view.
As regards to MUA population, some gaps still remain and some results for the smallest MUA should be interpreted with caution.
The MUA database comprises about 2000 citiesthroughout 29 countries (EU27 (1 January 2007 - 30 June 2013) plus Norway and Switzerland).