More than half of the Brazilian population (55.9%) lived, in 2010, in municipalities which formed population arrangements, that is, groups of two or more municipalities with close integration between their populations, due to commute to work or school, or to contiguity between their urban areas. That means 106.8 million persons in 294 arrangements, formed by 938 municipalities. A total 7.4 million persons commuted between the municipalities in the arrangement they live in, to work or to study. Given the existence of 27 frontier arrangements, that is, those also formed by political-administrative units in other countries, the number of residents amounted to 107.7 million.

These results are presented in the study 'Population Arrangements and Urban Concentration in Brazil', which also shows that the Southeast Region has the biggest number of arrangements (112), encompassing 72% of its population (57.8 million) and the Northeast, the smallest number (17), encompassing 23.5% of the local population (3.7 million). Manaus (AM), Campo Grande (MS) and Palmas (TO) are the only state capitals which do not form population arrangements. Urban concentration reached its highest results in “São Paulo/SP” (19.6 million inhabitants), “Rio de Janeiro/RJ” (11.9 million), “Belo Horizonte/MG” (4.7 million), “Recife/PE” (3.7 million) and “Porto Alegre/RS” (3.6 million).

Urban concentration is characterized by regular commute to work and school between municipalities. In the two biggest urban concentrations, commute is a reality for more than 1 million persons. It is the case of 'São Paulo/SP”, with 1,752,655 persons commuting between its municipalities, and of 'Rio de Janeiro/RJ', with 1,073,831. The main flows occur between the municipalities of Guarulhos (SP) and São Paulo (SP), Niterói (RJ) and São Gonçalo (RJ), Duque de Caxias (RJ) and Rio de Janeiro (RJ) and between Osasco (SP) and the state capital.

In spite of being about 430 km far from each other, Rio de Janeiro-São Paulo have a flow of 13.4 thousand persons between their arrangements, 57.7% of whom commute only because of work and 40.5% only because of school. The same way, the connection between the arrangements of “Goiânia/GO” and “Brasília/DF” leads to a flow of 8.8 thousand persons.

Besides leading to better knowledge of the Brazilian urban reality, the study provides additional material for the elaboration of public policies, and also fosters a partnership between the participating municipalities. The complete study 'Population Arrangements and Urban Concentration in Brazil' is available at :
https://www.ibge.gov.br/english/presidencia/noticias/images/2855_7737.gif.

The two biggest urban concentrations had more than 1 million persons commuting to work or study. In 'São Paulo/SP', the biggest flows occurred between the municipalities of Guarulhos and São Paulo (146.3 thousand) and between Osasco (SP) and São Paulo (112.4 thousand). In 'Rio de Janeiro/RJ' the main ones were between Niterói and São Gonçalo (120.3 thousand), Duque de Caxias and Rio de Janeiro (119,0 thousand) and between Nova Iguaçu and Rio de Janeiro (109.6 thousand). It is also important to highlight that the great occurrence of commute between the capital of Minas Gerais and Contagem, with 119.6 thousand, in the arrangement 'Belo Horizonte/MG' and of the capital of Pernanmbuco with Jaboatão dos Guararapews, with 118.2 thousand, in the arrangement 'Recife/PE'.

Flows between municipalities due to professional reasons were predominant in arrangements above 2.5 million inhabitants. More than 3/4 of these connections surpassed 70% of flows for these purposes. However, some connections had figures above 30% for school purposes. In 'Rio de Janeiro/RJ” this characteristic is stronger, in case, for example, of connections between Belford Roxo and Nova Iguaçu, in which 36.0% commute only for school purposes, 60.4% only for work purposes and 3.6% for both.

About 2 million people live in frontier population arrangements

A total 27 population arrangements were identified in the Brazilian international frontier, amounting to approximately 2.1 inhabitants, 44.2% of them living in neighboring countries. Out of these arrangements, sixteen were located in the South Region, including that with the biggest population - Ciudad del Este/Paraguai”, with 674.7 thousand inhabitants (59% of foreigners).

Rio Grande do Sul had 12 frontier arrangements, amounting to 607.5 thousand persons (36.3% foreign ones). The arrangement of “Sant’Ana do Livramento/Brasil – Rivera/Uruguai” is the third biggest one in the country with 161.4 thousand persons (48.9% of foreign ones). The North and Central West Regions had 11 population arrangements in groups, being five of them alone located in Mato Grosso do Sul.

Santa Catarina was a highlight due to its coastal population arrangements

There are also coastal population arrangements aimed at tourist and traveling activities. In general, their urbanized areas are contiguous or very close, and near the shore. In 2010, there were 49 municipalities participating and only five were not contiguous. However, this characteristic is not often followed by significant commute to work or school. These arrangements expanded their urban mesh in order to fulfill the demand for holiday leisure trips of the big metropoles nearby.

Among these, “Itajaí - Balneário Camboriú/SC” is the main population arrangement, with 479 thousand persons. An analysis of it together with “Itapema/SC”, shows the two arrangements reached the number of 555.6 thousand persons. This population total results, to a great extent, from the important function of Itajaí as a wharf and to its location close to arrangements in “Blumenau/SC” and Joinville/SC”. “Cabo Frio/RJ” and “Araruama/RJ” form the second biggest group, with 464.2 thousand persons.

The population arrangement of 'São Paulo/SP' is ore often linked to those of Campinas/SP', 'Jundiaí/SP', 'Sorocaba/SP', 'Baixada Santista/SP' and 'São José dos Campos/SP', among others. Together, these arrangements formed what is classified as 'polycentric or multigrouped aglomerations' which have several functions and potentialize the capacity of producing goods, rendering services, establishing partnerships and managing resources. As a result, “São Paulo/SP” forms what is called City-Region, which encompasses 89 municipalities and 11 population arrangements, amounting to 27.4 million inhabitants.

Rio – São Paulo connection had a flow of 13.4 thousand persons to work and study in 2010

The study identified some special cases of population arrangements, which represent relevant trends or aspects in the urbanization of Brazil.

One of them is the Rio-São paulo connection, which, in spite of the great distance between the two areas (approximately 430 km), presented flow of 13.4 thousand persons in 2010. From these, 57.7% occurr for professional reasons only, and 40.5% only due for educational reasons

The arrangement of “Macaé – Rio das Ostras/RJ” is also strongly connected to that of 'Rio de Janeiro/RJ”, reaching 12.8 thousand persons, in which 81.9% were related to work. In the est of Rio de Janeiro, connections between the arrangement of “Macaé – Rio das Ostras/RJ” with “Cabo Frio/RJ” and with “Campos dos Goytacazes/RJ” are also significant, surpassing 9 thousand persons in each connection. In case the economic dynamism of this region leads to increase of flows of persons between these two arrangements, that will generate a new urban unit with more than 1.2 million inhabitants.

The connection between “Goiânia/GO” and “Brasília/DF” had 8.8 Thousand persons in commute. It is Worth mentioning that, between these two arrangements can be found the municipality of Anápolis (334.6 Thousand inhabitants in 2010). Its importance lies in the fact that between this municipality and “Goiânia/GO” there were 6.0 Thousand persons commuting to work and study in 2010, and among this one and Brasília, 2.4 Thousand persons. As a result, this dynamics can be decisive in the formation of a new urban unit joining the arrangements of “Brasília/DF” and “Goiânia/GO”.

Population arrangements follow the pattern of Brazilian urbanization, with some exceptions in cases of very small populations. From a regional perspective, this spatial distribution is present in metropoles and in regional capitals.

The Southeast and South have the biggest number of arrangements (112 and 85, respectively), whereas the Northeast appears in the third position (56), followed by the Central West Region (24). In the North Region, where urbanization and dismembering processes are less significant, there is a smaller number of arrangements (17) and smaller participation of the population living in population arrangements.

The biggest flow of persons commuting to work or study was between Americana and Santa Bárbara d'Oeste (32.5 thousand persons), out of which 77.5% did it for professional reasons. Thirteen connections between municipalities surpass the figure of 10 thousand persons commuting, and work was the main reason for that. The main highlights in this case were Maringá and Paiçandu (PR). Commuting to study, in some cases, surpassed 30%: Balneário Camboriú and Itajaí (SC), with 33.3%, Petrolina (PE) and Juazeiro (BA), with 31.7%, and Cabo Frio and São Pedro da Aldeia (RJ), with 30.3%.

Brazil has 26 major great urban concentrations

The ones called big urban concentrations are population arrangements with more than 750 thousand persons and isolated municipalities of the same population range. In order to compare urban areas of similar size, the study divided this group into three ranges: above 750 thousand to 1 million inhabitants; above 1 million to 2.5 million inhabitants; and more than 2.5 million inhabitants.

In the range between 750 thousand and 1 million inhabitants were identified six great urban concentrations, out of which five consisted of population arrangements, except for Campo Grande. Only “Sorocaba/SP” is not a state capital. The number of municipalities is heterogeneous in the arrangements of this range, for there are cases such as “Cuiabá/MT”, formed by only two municipalities, whereas 'Florianópolis/SC” had ten and “Aracaju/SE”, 12 municipalities.

The biggest flows in terms of commute to work or school, internal in the arrangements, of this population group, were present in “Florianópolis/SC” (119.9 thousand persons). A total 54.1 thousand persons (45.2%) commuted between the municipalities of Florianópolis and São José and 20.4 thousand (17.0%) between the capital of this state and Palhoça. The population arrangemnt of “Aracaju/SE” amounted to 93.7 thousand persons, among whom 49.0% (45.9 thousand persons) commuted between the municipalities of Aracaju and Nossa Senhora do Socorro, and 29.3% (27.5 thousand) between Aracaju and São Cristovão. These two last calls had the biggest indexes of integration of this population range (0.58 and 0.70, respectively).

Eleven urban concentrations have between 1 million and 2.5 million inhabitants

Eleven urban concentrations with a population above 1 million up to 2.5 million inhabitants were identified. Four of them were located in the Northeast (“João Pessoa/PB”, “São Luís/MA”, “Natal/RN” and “Maceió/AL”), two in the North Region (Manaus, in Amazonas, and “Belém/PA”), four in the Southeast (“Vitória/ES”, “Campinas/SP”, “Baixada Santista/SP” and the Integration of 'São José dos Campos/SP”) and one in the Central West (“Goiânia/GO”). Except for the state of São Paulo, all the urban concentrations in this population range had state capitals as their center.

Also in this population range, the urban concentration formed by the biggest number of municipalities was “Goiânia/GO” (12), seguida pela 1a integração do arranjo de “São José dos Campos/SP” (10) e “Maceió/AL” (9). Out of the 11 urban concentrations, nine had more than 50% of their municipalities with contiguity of the urban area, but “Belém/PA”, “Baixada Santista/SP” and “São Luís/MA” formed, each one, the only urbanized area which covered all these municipalities.

Population arrangements which had the biggest volume of prsons commuting between municipalities to work and study, in this population range, were “Vitória/ES” (227.1 thousand), “Goiânia/GO” (191.0 thousand) and “Baixada Santista/SP” (161,2 thousand). The biggest flow between the municipalities was registered between Aparecida de Goiânia and Goiânia (GO), with 122.9 thousand, followed by Ananindeua and Belém (PA), with 93.5 thousand persons, and between Santos and São Vicente (SP), with 64.4 thousand persons.

Work was predominant as the main reason for such flows, surpassing 77.0% of the flows.

Biggest connections occur between Guarulhos and São Paulo

Among the nine urban population concentrations above 2.5 million inhabitants, three levels can be highlighted: the one between 3 million and 5 million inhabitants ('Belo Horizonte/MG', 'Recife/PE', 'Porto Alegre/RS', 'Salvador/BA', 'Brasília/DF', 'Fortaleza/CE' and 'Curitiba/PR'), that of 'Rio de Janeiro/RJ', with 11,946,398 and that of 'São Paulo/SP', with 19,613,759, in 2010.

The population arrangement of 'São Paulo/SP' concentrated 36 municipalities, the biggest number all over the country, and was followed by the 2nd integration of 'Porto Alegre/RS' (26) and by 'Belo Horizonte/MG' (23). Contiguity is a distinguishing aspect, and characterized 31 of the 36 municipalities in 'São Paulo/SP', an intense process also in 2nd integration of 'Porto Alegre/RS', with 19 municipalities forming two conurbation areas. The arrangement 'Rio de Janeiro/RJ' amounted to 18 municipalities in a single urbanized area, which is equivalent to 85.7% of its 21 municipalities.

In the Northeast, population arrangements are mainly located close to the coast, although they are also present in inner areas, especially those linked to traditional regional centers, such as Petrolina/PE - Juazeiro/BA, Juazeiro do Norte/CE, Campina Grande/PB e Caruaru/PE.

In the Southeast region, it is possible to observe that, in addition to metropoles, population arrangements are present in major urban centers. Highlights in Minas Gerais are Ipatinga/MG and Juiz de Fora/MG. In the state of Rio de Janeiro, the North Coast, with Campos dos Goytacazes/RJ and Macaé/RJ, besides Volta Redonda/RJ, in the area known as Vale do Paraíba (Paraíba Valley). In São Paulo, the arrangements belong to major economic centers connected by the following highways: Presidente Dutra (São José dos Campos/SP, Taubaté/SP), Anhanguera (Campinas/SP and Ribeirão Preto/SP), Imigrantes (Baixada Santista/SP), BR-456 (“Araraquara/SP” and “São José do Rio Preto/SP”) and SP-300 (Bauru/SP).

In the South Region, it is worth mentioning the North Coast pattern, formed by closely located population arrangements with a population from ranging 350 to 1 million inhabitants. The main municipalities in this group are de Joinville, Blumenau, Itajaí and Florianópolis. Other cities which form equivalent population arrangements are Criciúma (SC), Pelotas (RS), Caxias do Sul (RS), Maringá (PR), Londrina (PR) and Foz do Iguaçu (PR). The biggest arrangements are associated to the metropoles of Porto Alegre and Curitiba, both with populations close to 3 million inhabitants.

In the North and Central West Regions, the arrangements are linked, mainly, to major urban centers (Belém, Goiânia and Brasília).

63.6% of the population arrangements have up to 100 thousand inhabitants

Among the population arrangements, 187 (63.6%) have up to 100 inhabitants and are considered to have a low population concentration. These arrangements gather a total 8.4 million inhabitants (in Brazil and abroad) and 387 Brazilian municipalities, which correspond to 7.8% and 41.3% of the total present in population arrangements, respectively.

There is significant presence of these small arrangements in the surroundings of capitals such as São Paulo, Rio de Janeiro, Belo Horizonte, Porto Alegre, Salvador and João Pessoa (especially in Natal), and 75.9% of them are formed by two municipalities only.

Average urban concentrations grouped 18.6% of the population

Medium urban concentrations are isolated municipalities and population arrangements with more than 100 thousand up to 750 thousand inhabitants. Together they had 35.5 million residents, which was equivalent to 18.6% of the Brazilian population. Similarly to big urban concentrations, they have urbanization as the main process leading to the integration of municipalities, especially regarding the nucleuos of these municipalities. Besides, they have an average popuation size and can have unique urbanization areas resulting from the expansion of one or more cities.

There were 77 isolated municipalities, 81 population arrangements (being one of them a population arrangement integration, that is, an combination of arrangements), amounting to 368 municipalities. In this population group, “São José do Rio Preto/SP” and the 1st integration of “Presidente Prudente/SP” were the ones with the biggest number of municipalities, each of them formed by 12 municipalities. They are followed by “Ipatinga/MG” and “Criciúma/SC”, with ten municipalities, and “Maringá/PR”, with nine municipalities.

Out of the 81 arrangements, 30 (37%) had at least one municipality dismembered after the Federal Constitution of 1988. “Criciúma/SC” is the arrangement with most dismembered municipalities, three, or 30%. Considering arrangements with dismemebered municipalities, 11 are formed by only two municipalities, that is, probably the arrangement only exists due to this fact.

In relation to contiguity, 131 municipalities participating in arrangements (45%) had this characteristic. In “Itajaí - Balneário Camboriú/SC”, the seven municipalities forming it made up a single urbanized area. In the same context can be mentioned “Jundiaí/SP”, with its six municipalities forming a single urbanized area.