Abstract
The primary aim of the study was to identify the process of territorial development of large cities in Central and Eastern Europe based on the example of Wrocław. The analysis of the administrative boundaries changes; population density and land development revealed specific features of the territorial growth of large cities, which due to their repeatability indicate the cyclical nature of the processes. The specific pattern of territorial development in large cities can be described as follows: each period of socioeconomic development of the city contributes to an increase in population density within urban boundaries, and then to the sprawl of the city into its nearest neighborhood. The suburban area is an extension of the city and over time is incorporated into administrative boundaries of the city. Extension of the city usually reduces the population density within its new boundaries. Each subsequent period of prosperity in the city initiates another cycle of spatial development.
Keywords
Introduction
The spatial development of cities is one of the most glaring signs of urbanization. 1 The increase in population stimulates construction, and thus the expansion of cities. With the progress of this process, cities start sprawling outside their borders and with time incorporate suburban areas strongly linked with them. Moreover, this phenomenon is characteristic not only for modern cities, but it also took place in historical periods, for example, in the Middle Ages 2 and during the industrial revolution in the nineteenth century. 3 In modern cities, however, the range delineated by administrative boundaries of the city is often very different from the actual range designated based on other aspects of urbanization. In previous studies, researchers focused mainly on the issue of the spatial development of cities, 4 in particular, changes in population density in the city center and suburban areas analyzed in the context of the advancement of urbanization processes. 5 Only a limited number of studies concerned the territorial development of cities, as well as the relationship between the territorial and spatial development of cities. 6 The problem of spatial (territorial) development of large cities of Central and Eastern Europe was discussed on the examples of Berlin, 7 Budapest, 8 Kraków, 9 or Prague. 10
The present study in this area was inspired by observations regarding the specific nature of the territorial growth of Wrocław and other large cities in Poland, for which analysis revealed some similarities in settlement processes during different historical periods. This allows for the identification of specific regularities of growth, which due to their repeatability indicate the cyclical nature of the processes. First, two key concepts should be clarified from the point of view of the problems discussed in this article, that is, territorial development and the spatial development of cities. These terms are quite often used as synonyms, but are semantically different in their relationship with the shape of the administrative boundaries of the city. The territorial development of the city (including also territorial changes) is a growth (change) of the administrative area of the city, related to the widening (or narrowing) of its administrative boundaries, while the spatial development of the city follows the development of urbanized areas (especially built-up areas) within the boundaries or in the immediate vicinity of the city (suburbanization or development of the suburban areas), which usually does not change its administrative boundaries.
The following research hypothesis was adopted for the purpose of this study: the territorial development of cities is gradual (pulsatile), and each extension of its administrative boundaries follows a specific pattern and is a consequence of the social and economic growth of the city. This hypothesis was supplemented with four major research questions: (1) What is the relationship between the spatial and territorial development of the city? (2) What are the building (replacing buildings, filling plots, expansion of the city after climax) and destroying processes in the spatial development of the city? (3) Which social, economic, and technological (urban patterns) conditions as well as legal and political factors contribute to the spatial development of large cities? and (4) What is the influence of centripetal and centrifugal forces on the spatial development of cities? The problems of contemporary suburbanization and formal (administrative) borders of the city are also addressed in the study.
The research was carried out as a case study, with the main objective of identifying the process of territorial development of large cities in Central and Eastern Europe using the example of Wrocław. The choice of Wrocław was not accidental. The city is a regional center established in the Middle Ages (as the historical capital of Silesia, today the capital of the Lower Silesia Province), and now aspiring to become a metropolitan center. Wrocław has a population about 635,000 and an agglomeration about 1.1 million. 11 In the study (comparative analysis), we also show the examples of Warsaw and Kraków, another two regional centers with a long history (Masovia, Lesser Poland), whose development in certain historical periods was additionally stimulated when these cities were capitals of Poland (Kraków in 1038-1568, and Warsaw from 1568).
Theoretical Background
Theoretically, the spatial and/or territorial development of cities should be considered as an example of the expansion process. 12 According to E. W. Burgess, 13 the typical process of the expansion of the city can be illustrated by a series of concentric circles, covering both successive zones of urban extension and the types of areas differentiated in the process of expansion. It seems that for a long time, until the nineteenth century, the spatial growth of cities was mainly concentric. According to T. Hall and H. Barret, 14 the outward expansion of the industrial city consisted of residential development as the series of distinct landscapes was created by successive phases of suburban expansion, and its variety derives from the different periods during which suburbs have developed. 15 With advances in transportation technology, the spatial growth of cities has become more sectorial and follows the routes of main roads. 16 In addition, industrialization processes promoted polycentric growth, thus complicating the formation of urban spatial structures. 17
The issue of urban spatial structures is usually considered from the static perspective, while the essence of research is to develop a spatial model of a city universal or typical for a given region. Most important models include classical models of urban structure: concentric zone model, 18 sector model, 19 and multiple nuclei model, 20 as well as their modifications—core frame model, 21 the Mann model, 22 the Rees model, 23 the Hopkinson model, 24 the model of urban development in Latin American cities, 25 or models of urban spatial development in different regions of the world proposed by R. Stewig. 26
The spatial development of cities in most studies is analyzed in the context of changes in population density depending on the distance from the city center. Analyses in this area were initiated by C. Clark, 27 who concluded that the population density in the agglomeration decreases rapidly along with the distance from the center, and that the profiles of population density change over time. The problem of the urban population densities has been addressed in many publications, but those authored by B. E. Newling, 28 as well as L. H. Klaassen and J. H. P. Paelinck 29 deserve special attention. Newling conceptualized four stages of density gradients: youth, early maturity, late maturity, and old age stage. Klaassen and Paelinck analyzed the development of large cities and their suburban zones in the context of the progress in urbanization processes (identifying: urbanization, suburbanization, disurbanization, and reurbanization stage) and their spatial effects (centralization and decentralization). These studies have created a background for further analyses of changes in population density along with the development of the cities (urban agglomerations). 30
One particular attempt to link changes in population density with spatial development is the concept of the wave-like growth of the city proposed by P. Korcelli, 31 who investigated the spatial development of metropolitan areas in California. Analysis of changes in population density revealed subsequent waves of growth and stages within each of the cycles: penetration, invasion, consolidation and saturation, and sometimes also the phase of further slow growth (piling-up phase). Subsequent stages of innovation in the field of transport determined different models of spatial development of cities. The growth waves can be disturbed by distorting factors, including chronological changes (periods of prosperity and economic crises, technological changes, changes in people’s incomes, natural disasters) and differences in local resistance (positive—location benefits, course of administrative borders, and negative—natural barriers, institutional barriers). In addition, Korcelli distinguished three major processes of spatial succession related to the movement of growth waves: (1) the development of dispersed suburban settlements in areas previously unused or used extensively; (2) the transition from the agricultural use of land, or dispersed rural settlements, to dispersed suburban settlements; and (3) replacement of suburban land use with high-density built-up development, mainly multifamily buildings, with a large share of industrial and trade facilities.
A significantly lower number of studies focus on the spatial growth of cities, especially in the long-term perspective. Some particularly interesting theoretical approaches pointing to the sequence of growth processes and/or the cyclical nature of spatial urban growth include (1) a growth model for a nineteenth-century industrial city by R. Lawton, 32 (2) the concept of building cycles, 33 (3) the concept of fringe belts by M. R. G. Conzen 34 and J. W. R. Whitehand, 35 and (4) study on the development of Kraków spatial structure presented by R. Mydel. 36
The Lawton model 37 was based largely on Liverpool and its development in the nineteenth century. Lawton identified episodes of prosperity and episodes of decay during the history of the city. The concentric rings (Figure 1) result from cyclical phases of expansion when the economy prospers and consolidation or even stagnation during economic recession—these periods can be interpreted as the building cycles. In the Lawton model, preexisting patterns of land use contribute to differences between sectors—villages and small towns may be absorbed as the city expands and engulfs them. The arrows show the direction and relative strength of interurban and intraurban population mobility. According to R. Krzysztofik, 38 they can also be interpreted as the effects of centripetal and centrifugal forces, analyzed in the context of travel, goods transport, and socioeconomic connections.
R. Lawton’s model (1972) of urban development in the nineteenth century.
The concept of building cycles assumes a variable dynamics of building investments and the occurrence of booms in residential construction. 39 W. Isard 40 pointed to the relationship between the building cycles and the transport development, while J. R. Riggleman 41 referred to their link with the general business cycles. Studies by J. W. R. Whitehand 42 demonstrated, on the contrary, the effect of building cycles on the spatial patterns of urban growth. These relationships have also been supported by other authors. 43 R. Barras 44 identified six major building cycles for British cities, connected with (1) the first industrial revolution (1785-1856), (2) the second industrial revolution (1856-1888), (3) the age of electricity (1888-1918), (4) interwar turbulence (1918-1944), (5) the postwar consumer boom (1944-1981), and (6) the computer age (1981-2008).
The concept of fringe belts was proposed for the first time by H. Louis 45 in his study on the spatial growth of the Greater Berlin. Research into fringe belts was continued by M. R. G. Conzen and J. W. R. Whitehand, 46 who linked fringe belts with building cycles and bid rent theory, and combined them into the model of urban fringe belts (Figure 2). Fringe belts is a system of relatively concentric, separated rings characterized by extensive land use, successively increasing their importance in the urban space. Fringe belts are formed as a result of the stagnation or slow growth of peripheral areas, caused by emerging obstacles (fixation lines). Studies by other authors aimed at identifying fringe belts in the spatial structures of selected large cities. 47
Historic fringe belts, innovation and building cycles (Whitehand 1988).
R. Mydel 48 analyzed the changes of population density and land use intensity with the connection to the territorial development of Kraków between the twelfth century and 1975. He proposed the model of population density schemes which is composed of the six successive phases (youth phase, early phase of maturity, late phase of maturity, phase of old age, and the dispersion phase) and the model of the schemes of land use intensity which contains two stages and five phases. The convection stage was characterized by the growth of the town “toward the top” within the defense wall from thirteenth to nineteenth century (connected with the increase of land use intensity). The diffusion stage was characterized by the growth of spatial expansion of technical uses and divided into the connection phase (marked by strong spatial and functional relations with the central zone and a high degree of land use intensity) and the catabatic phase (marked by a great rate of diffusion processes as occurring in it and by the decreasing of the land use intensity).
Modern research investigating the spatial expansion of the city focuses on the analysis of changes in land use, in particular, the development of urbanized areas, using remote sensing data, geographic information system (GIS) and statistical models, based on the examples of single cities, mainly in China, 49 India, 50 Africa, 51 or Latin America. 52
Data and Method
The primary aim of the study was to analyze the territorial development of Wrocław, which required gathering information on changes in the administrative boundaries of the city from the thirteenth century, when Wrocław was granted town privileges, to modern times. Data on the population of Wrocław within its administrative boundaries were acquired to investigate the effect of specific changes in administrative borders on population density. This information was mainly sourced from censuses as well as available statistical databases. The first census for Silesia (including Wrocław) was done in 1747, and further ones were organized at variable intervals, every fifteen years on average. Earlier population data are in most cases estimates based on assumptions made by different authors, usually indicating the statistical relationship between the number of residential buildings and the potential number of inhabitants. Much less problematic are data on the administrative area of Wrocław, because it had strictly defined administrative boundaries since the moment of foundation. The only debatable data come from the period between the mid-fourteenth century and 1807, when Wrocław was surrounded by suburbs closely functionally related with the town, but actually remaining outside urban jurisdiction. The area of suburbs was not included in the total area of Wrocław; nevertheless, many researchers included suburban residents in the total population of Wrocław. Hence, to determine the actual population density within the town walls, the population of Wrocław was estimated based on the ratio of town to suburban population as shown in the census of 1747 (back then Wrocław’s population made up two-thirds of the entire agglomeration). To investigate the relationship (spatial correlation) between the territorial growth of the city and the actual spatial growth of urban areas, including urban buildings, available cartographic materials, in particular historical city plans, as well as topographic maps of this area from the middle of the nineteenth century to the present time were analyzed. The collection includes hundreds of maps and plans.
Territorial and Spatial Development of Wrocław
The history of Wrocław dates back to the ninth century. At that time, a stronghold was built on Ostrów Tumski (the Cathedral Island), which was one of the Silesian centers for the Slavic Ślężanie tribe. The stronghold was established at the intersection of important trading routes, connecting north and south (Adriatic-Baltic Sea), and east and west (Via Regia). At the end of the ninth century, Wrocław, together with the whole of Silesia, became a part of Great Moravia, and after its fall (in 907), it became a part of the Duchy of Bohemia. In the second half of the tenth century, Silesia became a part of the Piast State. Back then, Wrocław was a large stronghold surrounded by earth embankments and was an important center of trade and craft. 53 In 1000, a bishopric was established in Wrocław, and this event strengthened for good its position as the capital of the province. In the middle of the twelfth century, monasteries were built around the town (of St. Vincent north of the Odra River; Church of the Blessed Virgin Mary on Sand), in addition to the houses of noblemen, a colony of Wallonian weavers, a merchant district, and a new ducal castle on the left bank of the river. In 1226, south of the merchant district, the town with the central point, Nowy Targ market square, was founded. The growth of the left-bank town was stopped by the Tatar invasion in 1241. The town had to be rebuilt and charter privileges renewed in 1242. To the west of Nowy Targ square, a new market square (Rynek) was set out, along with the auxiliary market square (Plac Solny) and streets perpendicular to it. 54 The town was surrounded by a moat and a system of brick fortifications. Wrocław occupied an area of 0.6 km2 within its original borders. About the year 1300, the southern and western suburbs were incorporated into the town, and the whole town was surrounded with an additional belt of walls and an outer moat. Within the new borders, Wrocław occupied an area of 1.2 km2. In 1263, a new district, Nowe Miasto, was established east of Wrocław, and it was incorporated into the Wrocław borders in 1327 (Figure 3), which increased the town’s territory to 1.6 km2 and the population reached 16,400.
Wrocław in middle ages (Maleczyński et al., 1956).
These new borders of Wrocław remained largely unchanged until the end of the eighteenth century. And although numerous suburbs emerged around the city walls, they were formally outside the jurisdiction of the town authorities. At that time, the population of Wrocław gradually increased, although the increase was not very significant, which was due to many natural disasters (floods, fires), epidemics, and military operations (Hussite wars in the fifteenth century and the Thirty Years’ War in the years 1618-1648, after which the population of the city decreased from thirty thousand to twenty thousand). 55 The frequent changes in political affiliation did not favor the dynamic development of the town, either (Figure 4). In 1335, Wrocław was annexed to Bohemia, and in 1526 to Austria. The economic situation did not improve until Silesia went under Prussian rule in 1741. 56 The census of 1747 revealed that 33,500 citizens lived within the town walls (population density was 20,500 population/km2) and 16,500 lived in suburbs. By the end of the eighteenth century, the population of Wrocław including the suburbs rose to 58,300 (Table 1), and population density within the town walls reached 27,100 population/km2. The scale of the overpopulation is evidenced, for example, by the infill rate of street blocks, which in many cases was over 80 percent. 57 At that time, the town’s area was extended with developing fortifications to 3.5 km2.
Political affiliation of Wrocław.
Population of Wrocław in the Eighteenth Century.
The town reached a real turning point when Napoleon Bonaparte, after the conquest of Wrocław in 1807, ordered the demolition of the town walls, and this enabled rapid urban growth. 58 In 1809, the suburbs were incorporated into the boundaries of Wrocław, the city area increased to 20.5 km2, and the population to 78,100 in 1819. The territorial expansion of the city contributed to a significant decrease in population density within its borders (from 15,400 to 3,100 population/km2). Construction boomed on land incorporated by the city, and it was associated with a significant increase in the number of residents (Figure 5). Wrocław, with its developing industry, attracted numerous migrants from rural areas, who settled mainly in the tenement houses outside of the Old Town. Urban growth further accelerated after the construction of the railway in 1842. In 1852, Wrocław already had 120,100 residents, and the population density within city borders increased to 5,900 population/km2. The overcrowded and continuously developing city needed new land for construction. Therefore, in 1868, so-called villages of vegetable growers, located south of the city, were incorporated in Wrocław’s borders, 59 as well as two other villages, Rybaki and Szczytniki, located on the islands of the Odra River (Figure 6). Through this, the urban area increased to 30.2 km2. In 1871, Wrocław had 208,000 residents. The territory of the city further expanded in 1895-1911 to 49.2 km2. This, however, did not cause any significant drop in the population density within the city boundaries, since the population of Wrocław at that time increased to 335,200 in 1890 and 526,200 in 1911, and the population density reached 10,700 population/km2. Moreover, World War I did not bring significant damage to the city, nor did it contribute to a significant decline in the population.
Population of Wrocław, 1200-2018.
Territorial development of Wrocław, 1807-2019.
A seven-fold rise in the population in the nineteenth century increased the affluence of the society, the development of services, and the growing demand for private homes generated demand for free space. Wrocław was now an overcrowded city, with high-density development, and was bulging at the seams. It lacked green areas and open space, and therefore, in the interwar period, the administrative boundaries of the city were significantly extended and neighboring villages were absorbed. In 1924, the village of Sępolno was incorporated, and in 1928, two old towns (Leśnica and Psie Pole) and thirty villages (Figure 6), which increased Wrocław’s territory to 175.1 km2, and the population reached 625,200 in 1933. The territorial expansion of the city contributed to a significant decrease in population density, from 11,200 to 3,600 population/km2. In response to the overpopulation, garden towns (Karłowice, Sępolno) and single-family housing estates were established on the outskirts of Wrocław. 60 Such a significant extension of the administrative boundaries of Wrocław was possible due to convenient public transport and numerous railway lines, which ensured proper functioning of the city. The construction of new residential estates with single-family houses connected with the original rural development started, which contributed to significant changes in the morphology of the villages incorporated by the city. 61 However, a large part of the area was still used for agriculture.
Wrocław further grew its territory in the postwar period, but the process was not as rapid as in the interwar period. It resulted mainly from devastating damage during World War II, when about 70 percent of buildings were destroyed completely or partly. During the siege of the Breslau Fortress, most residents were evacuated from the city. 62 After the war, the remaining German population was relocated, and the Polish population started flooding in, but the destroyed city was inhabited gradually (in 1946, Wrocław had only 170,700 residents). In subsequent years, the population increased rapidly, reaching 308,900 in 1950, 430,500 in 1960, and 526,000 in 1970. However, new residential buildings were constructed mainly in the area destroyed during the war, and new built-up areas were created mainly in the peripheral districts of the city. Agricultural land continued to have a significant share of urban area. Despite that, in 1951, Wrocław formally absorbed the town of Brochów and nine villages, most of them situated south of the city, which was a zone strongly linked with the city and which already formed highly urbanized suburbs (Figure 6). After these changes, the territory of Wrocław increased to 225.0 km2, and the population increased by 16,075 people. The administrative boundaries of Wrocław were further modified in 1970-1973, and the change was related to the national urbanization plan, typical for states of the Socialist Bloc. During that period, the city incorporated fourteen villages (now located on the south-western and western outskirts of Wrocław), and as a result, its area increased by 67.8 km2 (to 292.8 km2), and the population by 9,179 people. Interestingly, in this instance, the city borders were not extended consistently with trends in spatial growth because Wrocław absorbed areas that were poorly urbanized and loosely connected with it.
Because of such significant changes in the administrative boundaries of Wrocław in the twentieth century, the city incorporated areas of rural character, located up to 15 to 17 km from the city center. Wrocław territory also included a significant share of agricultural land and forests, which currently occupy 40.9 percent and 5.2 percent of the administrative area of the city, respectively, separating individual morphological units. The territorial expansion of the city contributed to a significant decrease in population density. In 1973 alone, the population density in Wrocław reduced from 2,369 to 1,911 population/km2, and in 1951 from 1,597 to 1,373 population/km2. Most villages incorporated into Wrocław have become, over time (usually after twenty to thirty years), integral districts of the city, while some of them have retained their original rural character. Wrocław currently has over ten residential districts with a rural character, and a dozen or so others which transformed from villages to the centers (genetic nuclei) of postwar housing estates. 63 Most of them are located in the western and south-western parts of Wrocław, and on its northern outskirts, and therefore outside the areas which were affected by the most dynamic spatial growth of the city (south, east, northeast).
The Concept of the Cyclical Territorial Development of Large Cities
The analysis of changes in the administrative boundaries of Wrocław revealed some regularities. First, changes in the administrative boundaries of Wrocław followed a pulsatile pattern, and subsequent modifications alternated with periods of variable-length stability (Figure 7). Second, the territorial expansion of the city usually came after a period of dynamic social and economic growth within its existing boundaries and in the surrounding zone, strongly connected to the city and transformed under the influence of the city. In turn, most longer periods when boundaries were stable correspond to periods of social and economic stagnation of the city. Third, the boundaries of the city changed when a certain climax point of population density was exceeded, and the city could no longer grow within its existing boundaries. Each extension of the city boundaries contributed to the increase of the administrative territory of the city and population growth, and to a significant decrease in population density (Figure 8), because city (Wrocław) incorporated new, less urbanized areas that had free (potential) land for further urban growth. Fourth, the sequence of development processes and their specific repeatability show a cyclical nature, and subsequent cycles end the subsequent stages of the extension of the administrative boundaries of the city.
Changes in the administrative area of Wrocław, 1200-2019.
Changes in population density of Wrocław, 1200-2019.
A single cycle of changes in the administrative boundaries of the city consists of five basic phases (Figure 9). Phase I is the initial phase, which takes place at the moment of the city’s foundation (when its borders are defined) and in the case of subsequent cycles—the expansion of the city boundaries. During phase II, the number of residents and population density within the city borders increase as a result of socioeconomic growth. During phase III, population density within the city boundaries continues to increase, and after reaching the limit of its growth potential, the city sprawls to the nearest neighborhood. During phase IV, the impact of the city on its neighborhood stimulates further development of the suburbs (because of the stabilized population within the city boundaries). This process may also often include suburban villages or smaller towns strongly connected with the city. During phase V, the functional link between the city and its neighborhood (suburbs) is so strong that the administrative boundaries of the city are broadened to include suburban areas which are a natural extension of the city. This contributes to the increase of the city’s territory and population growth, and to a significant decrease in population density within the new boundaries. This phase is at the same time the initial phase for the next cycle of the spatial and territorial development of the city.
Cyclical model of the territorial development of large cities description of particular phases in the text.
In the case of Wrocław, seven full cycles of territorial development were identified (Figure 10). The first cycle concerns the development of the medieval town. It was initiated when Wrocław was granted town privileges in 1226 and when these privileges were renewed in 1242. The dynamically growing Wrocław quite quickly depleted space within the town walls, hence the rapid development of the suburbs around the town walls and the foundation of the second town (Nowe Miasto), complementary to the main town. This cycle ended with the extension of boundaries of the city to include the suburbs (1300) and Nowe Miasto (1327). In 1329, Wrocław had about sixteen thousand residents. The next growth cycle lasted until the early nineteenth century. At that time, urban development was repeatedly inhibited by military operations (Hussite wars in the first half of the fourteenth century, and the Thirty Years’ War in 1618-1648), as well as numerous epidemics and natural disasters. What is more, the unstable political situation was not favorable for urban growth. However, the most important barrier to the spatial development of the town was the town walls, which determined its range, thus limiting its growth to increasing population density. Therefore, the population in this period increased mainly within the town walls (from 16,000 in 1329 to 44,200 in 1799), and the population density increased rapidly (from 10,200 population/km2 to 27,100 population/km2), and less significantly in the suburbs directly neighboring the town walls. The overcrowded town needed free patches of land for further growth. Possibilities emerged when Napoleon Bonaparte decided to demolish the town walls (1807), and this contributed to the extension of Wrocław’s territory with its suburbs. In the nineteenth century, Wrocław had two cycles of growth following each other in a short time, and ending with the extension of the boundaries of the city in 1868 and in the years 1895-1911. In both these cycles, the scenario of changes was similar: the rapid population growth caused by the high birth rate and the inflow of migrants from rural areas resulted in a rapid increase in population density within the city borders, triggering a construction boom in new areas incorporated into the town. A gradual territorial development of the town in the nineteenth and early twentieth century turned out to be insufficient, especially in the context of a very rapid increase in the number of residents. The town still struggled with the problem of overpopulation, high-density development and lack of free spaces. Therefore, the peripheral areas began to develop around Wrocław, mainly exurbs well connected with the town via railway lines, but also suburbs directly neighboring the town. This cycle ended with the extension of Wrocław’s boundaries in the years 1924-1928, which resulted in a more than threefold increase in the administrative territory and a significant decrease in population density. Once the new land was acquired, the spatial growth of the city was no longer restrained. A construction boom was seen mainly in the newly incorporated areas, which partly transformed the morphology of old villages. 64 The further spatial growth of Wrocław within its new boundaries was slowed down by World War II. During the siege of the city, most buildings in the center and downtown districts were destroyed. This enabled the revitalization of street blocks to a large extent infilled with buildings. 65 It also turned out that the territorial development of Wrocław during the interwar period was not fully consistent with the actual directions of its spatial development. For example, Wrocław incorporated villages poorly connected with the city, located up to a dozen kilometers away from the center, while growing suburbs strongly linked with the city remained outside of its administrative boundaries (Figure 6). Modification of the city boundaries in 1951 aimed at the inclusion of the southern, eastern, and northern suburbs, which were the extension of the city. Another, seventh cycle of the territorial development of Wrocław was associated with the rapid population increase in the postwar period. Population density in Wrocław had already reached 2,400 population/km2 in the 1970s which, in the face of planned industrialization and urbanization, forced the extension of the city boundaries in 1970-1973. At that time, Wrocław incorporated villages poorly connected with the city, located south and north-west of the city center, which, to a large extent, have preserved their rural character to this day. What is more, from that moment, the population density within the city borders did not go over the level from the 1970s, and this was related to the slowdown of urban growth in the 1980s. Serious changes in the spatial development of the city were brought about by the socioeconomic transformations after 1989. The transition from a centrally controlled economy to a free market economy triggered suburbanization processes around large cities throughout Central and Eastern Europe. 66 Wrocław has recently seen a rapid development in the suburban area and in peripheral districts, as well as an increase in connections between the city and its close neighborhood (Figure 11). 67 Whether (or rather when) this cycle of spatial development of the city will end with the extension of its administrative boundaries remains an open question.
Cycles of territorial development in Wrocław.
Model of concentration of industrial activity in the Wrocław suburban zone (Brezden’ and Szmytkie, 2019)
Interestingly, similar processes have taken place in other large cities in Poland and throughout Central and Eastern Europe. In Poland, the cyclical nature of territorial development is seen, for example, in Kraków and Warsaw. For Kraków, six full cycles of territorial development can be identified (Figure 12). However, the timeline of the administrative boundaries of Kraków is different to that of Wrocław (1450, 1792-1800, 1900-1915, 1941, 1951, 1973-1986), 68 because Silesia and Lesser Poland had a different history. The slower development of Kraków in the industrial era (the nineteenth century) is also observable, which is why Kraków had only one (and not two as Wrocław) full cycle of territorial development during this period. Currently, as in the case of Wrocław, construction of buildings is possible because of the significant share of agricultural land (46.6%) available within the Kraków boundaries, hence the booming construction in peripheral residential districts (internal suburbs). A different pattern of spatial development is observed, however, in Warsaw (Figure 13), which became a regional center in the fifteenth century, much later than Wrocław or Kraków, but developed rapidly after 1568, after the capital of Poland was moved here from Kraków. From then on, Warsaw grew much more dynamically, and thus went through more full cycles of territorial development (eight), and each cycle ended with the change of city boundaries, in 1579, 1655, 1786, 1831, 1908-1916, 1951-1957, 1977, and 1992-2002. What is more, Warsaw is now approaching the next limit of population density (according to the Central Statistical Office, the population density in the city is 3,400 population/km2, but in fact this value may be up to 4,500-5,000 population/km2), and the city is slowly beginning to lack space for further development (the share of agricultural land is 22.8%, while the share of built-up and urbanized land is 56.0% compared with ca. 44.0% in Wrocław and Kraków). Because of this situation, ideas have emerged in recent years to further extend Warsaw’s administrative boundaries. 69
Cycles of territorial development in Kraków.
Cycles of territorial development in Warsaw.
Discussion
Previous chapters focused mainly on the factors that have a positive or negative impact on the spatial development of cities, as well as on the economic, social, technological, and political determinants of this process. It was demonstrated that the territorial growth of the city follows a period of socioeconomic growth, while longer periods of stability of administrative boundaries coincide with periods of stagnation or the impact of negative factors (e.g., military operations, natural disasters, unstable political situation, periods of economic stagnation), which is consistent with studies by Lawton, 70 the concept of building cycles, 71 and the concept of fringe belts, 72 and also refers to the observations on the development of the spatial structure of Kraków made by Mydel. 73 Transportation has also played a significant role in the spatial growth of cities. The influence of progress in transportation technology on the spatial growth of cities is illustrated by the model of fringe belts proposed by J. W. R. Whitehand. 74 Moreover, growth stages proposed in the model of fringe belts (Figure 2) correspond well with the periods of boom in construction and processes of changes in administrative boundaries that end the individual cycles of territorial development of Wrocław. In the case of Wrocław, however, it is difficult to distinguish subsequent fringe belts, apart from the Old Town Promenade (created in the place of the former city walls) and the city moat, which may indicate the very rapid spatial development of the city in the nineteenth and twentieth centuries.
The spatial development in cities accelerated in the nineteenth century, and industry was the driving force of this process. As Lawton 75 showed, this growth was initially concentric, which is also visible in the case of Wrocław. With the development of transportation in the late nineteenth century, spatial growth attained a sector-like pattern, since large cities began to grow along the main transport routes, and in particular toward smaller towns in their neighborhood. In Wrocław, the concentric pattern of the territorial growth was distorted by the following towns: Leśnica, located 12 km to the west, and Psie Pole, located 7.5 km to the northeast of the city center. According to R. Krzysztofik, 76 this results from the fact that some potential of the smaller towns was engulfed. This trend is also well illustrated by the extension of Wrocław’s administrative boundaries in 1928, which contributed to the spread of the urban territory in the abovementioned directions. In addition, subsequent modifications to the administrative boundaries of Wrocław in the twentieth century led to the incorporation of rural areas unaffected by dynamic urbanization, and which still developed according to the concentric pattern, mainly because of convenient transport connections with the city center. 77
It was also demonstrated that the increase in population density within the city limits entails an increase in the share of urbanized areas (by greater infill or vertical construction). In this respect, one can find connections between the phases of the territorial growth cycle of the city and the phases of cycles of urban plots proposed by Conzen. 78 This connection can be manifested in two aspects. First, urban sprawl occurs after a certain level of population density is reached, which can be identified with the phase of climax, that is, the maximum filling of the plot (street block). Second, areas incorporated into the city go through a sequence of events according to the model proposed by Conzen, and their dynamics is high, so the transition from the initial phase to climax may take place within just several decades. The case study of Wrocław also shows that street blocks can be revitalized through higher density development or complete/partial elimination of buildings (e.g., as a result of war damage).
Analysis of changes in the administrative boundaries of Wrocław in the twentieth century revealed that territorial development does not always mean the actual spatial development of the city. Back then Wrocław absorbed villages poorly connected with the city, and their level of urbanization is so low that many of them have retained their original rural character. This process is typical for many cities of the Socialist Bloc, which, under the planned urbanization of the country, have often been spread beyond needs, and this influenced their spatial structures. 79 This problem is clearly visible in the case of Prague or Budapest. 80 Paradoxically, such a territorial expansion of the city now allows for the growth of internal suburbs (thus counteracting proper suburbanisation) 81 , since the new housing estates are built mainly on agricultural land, which in many cities constitutes a significant share of their area.
It should also be noted that the growth of suburbs is an inherent element of the spatial development of cities. 82 Moreover, it is not a new phenomenon and was initiated in the industrial era, at the end of the nineteenth century. Similar patterns of suburbian growth have been observed much earlier, because how else can one classify the growth of medieval towns? However, this process concerns a specific group of cities—monocentric regional centers developing as a result of the influence of centripetal forces in the physicalism and functional approach (forces balancing the development of the city and its hinterland; Figure 14). 83 Their position in the region in most cases was established in the Middle Ages, which enabled them to develop for a long time and to build a strong and diversified functional economic foundation. The cities of the industrial era developed (and now shrink) much faster and more dynamically. In their case, we can also find the signs of cyclicality in spatial development, but individual cycles are significantly shorter. In addition, industry stimulates polycentric growth 84 and therefore the overlap of similar processes is commonly observed in closely spaced centers.
Activity of the city-forming centripetal forces in the settlement subsystem (Krzysztofik, 2016).
Summary
The analysis of changes in the administrative boundaries of Wrocław, in population density, and spatial development revealed specific features of the territorial growth of large cities in Central and Eastern Europe, as well as the similarity of settlement processes in different historical periods. This allowed for the identification of specific regularities of growth, which due to their repeatability indicate the cyclical nature of development processes. The specific pattern of territorial development in large cities can be described as follows: each period of socioeconomic development of the city contributes to an increase in population density within city boundaries, and then to the sprawl of the city into its nearest neighborhood (suburban zone). Research on the issue of long-term spatial and territorial development of large cities are quite rarely undertaken. Works discussing periods of intense development of the city are much more common, especially analysis concerning the suburbanization processes currently observed around large cities of Central and Eastern Europe. 85 The presented model also explains the specificity of spatial development of large cities of postsocialist countries in the postwar period, which in this aspect differ significantly from the development of large cities in Western Europe. The suburban area is actually an extension of the city, and over time is incorporated into its administrative boundaries. Extension of the city usually reduces population density within its new boundaries. Each subsequent period of prosperity in the city initiates another cycle of territorial development. The unstable socioeconomic situation of the city limits its spatial development and coincides with longer periods of stability of its administrative boundaries. The above described cyclical pattern of territorial growth concerns a specific group of cities—monocentric regional centers developing as a result of the influence of centripetal forces in the physicalism and functional approach. The presented research also revealed that the territorial development of the city is not always consistent with the actual directions of its spatial development. Significant extension of administrative boundaries was typical in the twentieth century in large cities of Central and Eastern Europe, and particularly common in the times of the centrally controlled economy, focused on planned urbanization and industrialization. Currently, cities in this region have entered a phase of dynamic suburbanization, which contributes to the significant development of urban areas, especially around large cities.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The article was the result of the implementation of the research project No. 2017/01/X/HS4/00969 financed by the National Science Center, Poland.
