Iwona Jażdżewska

Abstract Graph theory was used to present the connectivity and regionalisation of Poland’s network of urban settlement in 1931, 1950 and 2002. The vertices show towns and cities (as points), while the edges reflect distances between such urban centres, where these are located no further than 25 km apart. Simple graphs were used, and advantage taken of the properties of connected and disconnected (cohesive or non-cohesive) graphs, with graph connectivity studied to assess persistence in the settlement network. A connected graph may become disconnected when one vertex is removed, and in the context of the urban settlement network this denotes a town or city losing its rights and becoming part of the set of rural settlements. Conversely, a disconnected graph becomes connected when a new town or city in the network is founded. An important issue here is determination of the degree to which a connected graph can be regarded as connected. This is achieved by considering the number of edges needing to be removed from a graph before disconnection takes place. Such aspects of connectivity of the urban settlement network, as well as the forms it assumed in 1931, 1950 and 2002, have been presented against the backdrop of historical circumstances. Furthermore, urban settlement networks were considered regional if they could be represented by biconnected graphs. In fact, it was possible to distinguish several sub-graphs present at the beginning of the 21st century and representing permanent urban settlement networks (Fig. 8). These were the urban networks of the Wielkopolska region, as well as Lower Silesia, Kujawy, Upper Silesia, the Cracow agglomeration, Gdansk Pomerania and Western Pomerania, as well as Warmia and Mazury. Smaller and younger regions also represented by biconnected graphs included the agglomerations of Warsaw, Łódź, Białystok and Rzeszów, as well as the towns of the Świętokrzyskie, Lublin, Zamość, Lubuskie and Wolin regions.Thanks to analysis utilising graph theory, it was possible to note that the oldest regional urban settlement network (Silesia, Wielkopolska, Western Pomerania, Warmia and Mazury) takes the form of multiple circles. Most connected full graphs can be found in “young” towns and cities in Upper Silesia, the Dąbrowa Basin and, partially, the Warsaw agglomeration. The modern shape of urban settlement networks is influenced by railways, as can be seen in the cases of Warsaw and the Rzeszów agglomeration, as well as the Świętokrzyskie, Łódź and Białystok regions. After 1945, the connection of the urban settlement network of the so-called Regained Territories with the urban areas of Wielkopolska, Kujawy and other regions still separated by a state border as of 1931 may indicate the existence of a supranational region before World War II. Thanks to the functions provided by GIS tools and, in particular, the utilisation of additional layers with rivers and historical borders in graph analyses, the interpretation of graph connectivity was able to take into account the historical aspect.

Keywords: miejska sieć osadnicza, teoria grafów, Polska, GIS (System Informacji Geograficznej)

Iwona Jażdżewska, University of Łódź Faculty of Geographical Sciences Kopcińskiego 31, 90-142 Łódź: Poland

Citation

APA: Jażdżewska, I. (2017). Spójność i regionalizacja miejskiej sieci osadniczej w Polsce w świetle teorii grafów. Przegląd Geograficzny, 89(2), 213-231. https://doi.org/10.7163/PrzG.2017.2.2
MLA: Jażdżewska, Iwona. "Spójność i regionalizacja miejskiej sieci osadniczej w Polsce w świetle teorii grafów". Przegląd Geograficzny, vol. 89, no. 2, 2017, pp. 213-231. https://doi.org/10.7163/PrzG.2017.2.2
Chicago: Jażdżewska, Iwona. "Spójność i regionalizacja miejskiej sieci osadniczej w Polsce w świetle teorii grafów". Przegląd Geograficzny 89, no. 2 (2017): 213-231. https://doi.org/10.7163/PrzG.2017.2.2
Harvard: Jażdżewska, I. 2017. "Spójność i regionalizacja miejskiej sieci osadniczej w Polsce w świetle teorii grafów". Przegląd Geograficzny, vol. 89, no. 2, pp. 213-231. https://doi.org/10.7163/PrzG.2017.2.2