The IBGE has released a new six-month update of the list of municipalities that compose the Metropolitan Areas (RMs), Integrated Development Areas (RIDEs) and Urban Agglomerations defined by the State and the Federal governments, based on information of December 31, 2019.

Since 2013, the IBGE updates, every semester, the composition of the different RMs, RIDEs and Urban Agglomerations in the country. Further information is available here.

Areas in Rio de Janeiro and Alagoas faced changes 

The current update of the IBGE shows the inclusion of new municipalities in the metropolitan areas of Rio de Janeiro and Alagoas. In Rio de Janeiro, the municipality of Petrópolis, in the mountainous region of the state, has been reintegrated as a metropolitan area of the state, according to Complementary Law no.  184/2018.

The state of Alagoas, as a result of Complementary Law no.49/2019, has incorporated the municipality of Atalaia to the RM d of Vale do Paraíba, and the municipalities of Igaci, Palmeira dos Índios, Estrela de Alagoas, Belém and Tanque d’Arca to the RM of Agreste, amounting to 18 municipalities. In the RM of Caetés, in the state of Alagoas, Complementary Laws no. 48 and 49 deal with the inclusion of two municipalities: Coruripe and São Miguel dos Campos.

No changes have been recorded in the Brazilian integrated development areas (RIDEs), or in the other metropolitan areas of the remaining states. There are, nowadays, 74 metropolitan areas in the country; the of Paraíba holds the biggest number of them (12), followed by Santa Catarina (11), Alagoas (9) and Paraná (8). There are five Urban Agglomerations: three in the state of São Paulo and two in Rio Grande do Sul.

The metropolitan areas and urban agglomerations are subdivisions set in accordance with the Federal Constitution of 1988, aiming at an integrated process of organization, planning and execution of common-interest public functions. The establishment of metropolitan areas and urban agglomerations  is a duty of the state government, according to Paragraph 3, Article 25, of the Federal Constitution.

The Integrated Development Areas (RIDEs), in turn, area defined as administrative regions that encompass different Federation Units. The RIDEs are created by means of specific laws that list the selected municipalities and define the functioning structure of those participating political and administrative units. In the case pf RIDEs, their creation is a duty of the Federal government, according to Paragraph 1, Article 43 of the Federal Constitution of Brazil.