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Exploring the patterns of urban growth across 26 European countries 2771
settlement structures and for all countries of the European Union. The size of the 20 × 20 km
grid was selected as a compromise between the intention to provide suf cient detail to detect
regional patterns, and data accuracy limitations. Country measures were calculated either by
computing aggregate statistics or mean values of all raster cells that cover a country.
The mapping of indicators required processing of large amounts of geodata in a
geographic information system. For most composition indicators, simple overlay techniques
were suf cient to extract overlapping geographic features and transform aggregated indicator
values to the reference grid. Pattern measurements were more complex to calculate, since
they required spatial analysis techniques to assess the form and distribution of polygons
within each cell of the reference grid. The work ows required iterations of analysis routines
that were mostly implemented in ArcGIS model builder. In some cases, raster processing and
conversion techniques were utilised to combine and integrate data formats within the vector
analysis work ow (urban density, soil sealing). Detailed formulae for indicator calculation
are given in the appendix; for further details see Siedentop and Fina (2010).
3 Results
Table 2 presents an overview of average indicator values on a country scale, starting with
general information on the total land area and population size. Within this context, each
country is then portrayed by the aggregated indicator results of the urban sprawl dimensions
explained above (composition, pattern, density). The top- ve countries in terms of most
sprawl-like indicator values are shaded grey in the respective cells. Selected maps complement
these results and are discussed below.
3.1 Change in land-use composition
Most of our sample countries are characterised by uneven territorial distribution of urban
land and growth of urban land. The maps in gure 2 illustrate the variations on the regional
scale for the EU member states that provide CORINE data for 2006. (1) The base map of the
urban land consumption within each cell [indicator 1, gure 2(a)] highlights the high levels
of urbanisation in regions between the North Sea and the Black Sea. A large cluster of cells
with more than 10% of urban area can be found in Belgium, in neighbouring parts of the
Netherlands and Germany (the Rhine-Ruhr agglomeration and the southwestern parts of
Germany), and northern Italy, divided by the Alps. This well-known Central European
‘pentagon’ area represents the economic heart of Europe and therefore pressure on
land resources is assumed to be above average here. In Southern Europe high levels of
urbanisation are concentrated mainly in urban agglomerations along the coasts (apart from
Madrid). Especially along the north Portuguese, the Spanish, and French Mediterranean
coastlines a nearly closed belt of urban areas has emerged since the 1950s and the beginning
of mass tourism in these regions.
After normalisation by population density (indicator 2), a comparison of this urban area
distribution against the European average shows that large parts of Scandinavia and the Baltic
States, of France/Belgium/Luxemburg, and of the Eastern European countries (extending
to Eastern Germany but excluding Poland) rank highest [normalized land consumption,
gure 2(b) and table 2]. This aspect points towards a higher land consumption rate per capita
in these areas which is an important measure for ef ciency assessments of urban structures.
The deviation rates for this indicator in table 2 con rm these ndings on the national level.
The distribution of urban areas seen here is certainly the legacy of hundreds of years of
urban development. However, large parts have only been developed in recent years (growth
of urban land, indicator 3 in table 2 and gure 3). The most prominent countries affected
(1) Note that we have substituted the missing 2006 data for the United Kingdom and Greece with the
2000 dataset.