*2.1. Study Area*

The study area includes: The Metropolitan Area of Warsaw (MAW), the Upper Silesia-Zagł ˛ebie Metropolis (US-ZM), the Kraków Metropolitan Area (KMA), the Poznan Metropolitan Area (PMA), the Metropolitan Area of Gda ´nsk-Gdynia-Sopot (MAG-G-S), the Wrocław Metropolitan Association (WMA) and the Łód´z Metropolitan Area (LMA) and the Ruhr Metropolis (RM, Germany) (Figure 2, Table 1). The majority of the studied metropolitan areas are monocentric agglomerations. Only US-ZM and RM have a different spatial character (polycentric). Furthermore, both US-ZM and RM have an industrial (mining) origin, similar polycentric character and high population density (the value of the population density index: 904 and 1163) [38].


1 Strategy of development of the Metropolitan Area of Warsaw until 2030, 2015. 2 https://metropoliagzm.pl. 3 Krakow Metropolitan Area in 2011–2015, 2016. 4 Delimitation of Poznan Metropolitan Area, WBPP (http://www.wbpp.poznan.pl/opracowania/POM/POM.html). 5 www.metropoliagdansk.pl. 6 Spatial development plan of Lower Silesian voivodship. 7 Strategy of development of Łód ´z Metropolitan Area 2020+. 8 https://metropole.ruhr.

> In this article, administrative criterion of delimitation of metropolitan area was adapted, based on diverseofficial documents (Table 1) [39–46]. The borders adopted in official documents delimit very large areas. It must be emphasized that according to these administrative bases, metropolitan areas may also include rural communities. The structure of the types of communities in Polish metropolitan areas is presented in Figure 3. Analyzing this characteristic, only in US-ZM in Poland urban municipalities dominates.

**Figure 2.** Study area. Symbols of the metropolitan areas—see Table 1.

**Figure 3.** Percentage of administrative types of communities in Polish metropolitan areas.
