IBGE adopted some innovations in 2010 to improve the identification of subnormal agglomerates – irregular settlements such as favelas, invaded properties, caves, slums in glens, poor communities, shanty towns, slums in backwaters, mocambos (type of shack), stilt houses among others.

The publication Subnormal Agglomerates – First Results will be released next Wednesday, December 21^st, aiming at showing how many people live and how many households exist in these areas, how they are distributed in the country and in the cities and how the services of water supply, sewage collection, garbage collection and electric energy work in those areas. The full publication will be available on the web page of IBGE, including tables containing information for each agglomerate and files with their limits in shape file (SHP) and KMZ (compatible with Google Earth) formats.

It is not the first time that IBGE addresses this issue in a specific publication.

IBGE released the publication "The Favelas of the Federal District and the 1950 Population Census in 1953 ", when it was detected that 7.2% of the population of the Federal District (169,305 inhabitants) lived in favelas. Since then, this issue has gained more dimension and complexity with the acceleration of the urbanization in Brazil.

The concept of subnormal agglomerate was used for the first time in the 1991 Population Census. It contains a certain level of generalization in order to encompass the diversity of irregular settlements that exist in Brazil, known as favelas, invaded properties, caves, slums in glens, poor communities, shanty towns, slums in backwaters, mocambos (type of shack), stilt houses among others.

The Manual of Delimitation of the Enumeration Areas of the 2010 Census considers as subnormal agglomerate any settlement with a minimum of 51 household units, mostly in need of essential public services, occupying or having occupied until recently a third-party property – public or private – and generally arranged in a disordered and dense way.

The identification has to meet the following criteria:

a) Illegal occupation of land, i.e., construction in a third-party property – public or private – now or recently (ownership title of the property obtained in 10 years or less); and

b) Urbanized out of the legal standards – reflected by narrow and irregular ways, plots with different sizes and formats and constructions not legalized by public offices – or low provision of essential public services (water supply, sewage collection, garbage collection and electric energy).

IBGE adopted methodological and operational innovations in the 2010 Census in order to improve the identification of the subnormal agglomerates. High resolution satellite images and a specific survey about the morphology (Territorial Information Survey - LIT) were used as well as specific meetings were carried out at the Municipal Commissions of Geography and Statistics – CMGEs. As a result of these improvements, the outcomes are not directly comparable with the previous censuses. 

The high resolution satellite images were a qualitative improvement for the identification of the agglomerates over the previous censuses. The images were used to identify parts of the municipalities morphologically similar to subnormal agglomerates, which were later confirmed by field investigation. 

The Territorial Information Survey was conducted in 2009, assessing the land and legal conditions of the agglomerates in the city halls as well as collecting field data like characteristics, localization, urban standards and occupation density. The survey aimed at improving the identification of the subnormal agglomerates as well as collecting territorial information for later classification. 

Lastly, the specific meetings about subnormal agglomerates carried out in 2011 at the Municipal Commissions of Geography and Statistics – groups in all the 5,565 municipalities formed by representatives from IBGE, from the city halls and from the society that worked as communication channels along the entire 2010 Census – contributed to update files and maps. 

The denomination and eventual subdivision of an area into different subnormal agglomerates is a social and political initiative. The comparisons between agglomerates should take into account that they could be unique – isolated areas – or interconnected to others – contiguous areas. In Rio de Janeiro, for example, Rocinha was a single subnormal agglomerate in 2010, while Morro do Alemão formed an area interconnected to other 9 agglomerates (Itararé, Joaquim de Queiroz, Morro da Baiana, Morro das Palmeiras, Mourão Filho, Nova Brasília, Parque Alvorada, Relicário and Vila Matinha):

The IBGE files contain information about each agglomerate and totals for municipalities and Federation Units.

Therefore, data will not be available for categories like complexes of favelas or any other group. It is important to mention that a subnormal agglomerate may have the same name of a district – legal division of municipalities – whether or not they match. For example, the area formed by Morro do Alemão and interconnected agglomerates does not match with Complexo do Alemão district, as depicted below: