The IBGE carried out another biannual update of the list of municipalities that comprise the Metropolitan Areas (RMs), Integrated Regions of Economic Development (RIDEs) and Urban Agglomerations, based on information provided by the states on December 31, 2014. In addition, the lists of municipalities that comprise the Legal Amazon and the Brazilian Semiarid regions have been improved. The updates also followed guidelines from the Ministry of National Integration, as well as the legislation in force.  Since 2013, the IBGE biannually updates in its website the composition of every existing RM, RIDE and Urban Agglomeration. Other information about regional units can be accessed on link  http://downloads.ibge.gov.br/downloads_geociencias.htm

Revision shows changes in RMs in Ceará, Paraíba, Roraima and Santa Catarina

Sixty-six Metropolitan Areas exist today in Brazil. Paraíba is the state with the highest number of RMs (12), followed by Santa Catarina (9) and Alagoas (8). The current revision brings changes in the RM of Fortaleza (CE), which included the municipalities of Paracuru, Paraipaba, São Luis do Curu and Trairi; in two RMs of Paraíba, in which the municipalities of Guarabira and Itabaiana were respectively included in the Metropolitan Areas of Guarabira and Itabaiana; in two RMs of Roraima, in which the municipalities of Alto Alegre, Bonfim and Mucajaí were included in the Metropolitan Area of the Capital, and the municipality of Rorainópolis, in the Metropolitan Area of the South of the state; and in Santa Catarina, in which the legislation of the Metropolitan Area of Florianópolis has been updated (Supplementary Law no. 636 of September 9, 2014).

The revision does not introduce any change in the lists of municipalities that comprise the Integrated Regions of Economic Development (RIDEs): those of Petrolina/Juazeiro, Great Teresina and the Federal District and Surroundings. The four existing Urban Agglomerations in Brazil did not change as well: Jundiaí (SP), Piracicaba (SP), South-RS and North Shore-RS.

The Metropolitan Areas and the Urban Agglomerations are units established by state supplementary laws, according with the Federal Constitution of 1988, aiming at integrating the organization, planning and implementation of public services of common interest. On their turn, the RIDEs are defined as Metropolitan Areas located in more than one Federation Unit. They are created through a specific legislation, which defines the municipalities that comprise them and establishes the competencies taken over by their collegiums.

According with Article 25, 3rd Paragraph, of the Federal Constitution, Metropolitan Areas and Urban Agglomerations are under the jurisdiction of the States. In the case of the RIDEs, Article 43, 1st Paragraph, of the Constitution establishes that they are under the jurisdiction of the Union.

Mojuí dos Campos (PA) now part of Legal Amazon

The Legal Amazon was established by Law no. 1,806, of January 6, 1953, which created the Superintendence of the Economic Valorization Plan of Amazon. It was changed by Supplementary Law no. 124, of January 3, 2007, which recreated SUDAM. 772 Brazilian municipalities comprise this unit today. Stretched along 5,020,000 Km², the Legal Amazon matches the area of all the states of the North Region (Acre, Amapá, Amazonas, Pará, Rondônia, Roraima and Tocantins), plus the state of Mato Grosso (141 municipalities) and plus 181 municipalities of Maranhão located west of meridian 44º. Emancipated from Santarém in 2013, the municipality of Mojuí dos Campos (PA) was the only included since the last IBGE publication in 2007. The 2007 list has been improved with the inclusion of the municipality of Bacuri (MA) and the exclusion of the municipality of Nina Rodrigues (MA).

Semiarid encompasses 986 Brazilian municipalities

Created through Ministerial Order no. 89 of the Ministry of National Integration, of March 16, 2005, based on the Final Report of the Inter-ministerial Work Group for the Re-delimitation of the Northeastern Semiarid and of the Drought Polygon, the Semiarid encompasses 986 Brazilian municipalities stretched along an area of 982,563.3 km², of which about 89.5% is located in the Northeast Region and 10.5% in the state of Minas Gerais (85 municipalities). Except for Maranhão, all the states of the Northeast have municipalities in the Semiarid: 265 municipalities in Bahia, 170 in Paraíba, 150 in Ceará, 147 in Rio Grande do Norte, 127 in Piauí, 122 in Pernambuco, 38 in Alagoas and 29 in Sergipe. The area has been delimited based on two technical criteria: the 800 mm isohyet - curve line representing the points with equal rainfall, used in meteorological cartographic maps - has been delimited according with Thornthwaite Aridity Index of 1941 (municipalities with index up to 0.50) and with the Drought Risk (above 60%). Due to the vagueness of the federal law that created this unit, the current revision excluded the municipalities of Aroeiras do Itaim (PI) and Barrocas (BA). Nevertheless, it should be highlighted that both municipalities are located within the Semiarid area.