How to identify adjacent municipalities in Brazil?


I am working on the Brazilian censuses 1980, 1991, 2000 and 2010.

I would like to merge some “small” adjancent municipalities with few observations.

I wanted to merge some of them belonging to a common mesorregion since, in theory, a mesorregion is a group of municipalities. Unfortunately, it appears that many muncipalities belong to several mesorregions at a time in the data.

Otherwise, I could perhaps detect municipalities with a common border by spotting groups of individuals indentified by the variable STRATA that would belong to several muncipalities. However, I am not sure this is a valid procedure.

Do you have any suggestions?

Thanks for your help.



We are in the process of creating harmonized states and municipios for Brazil, which would account for boundary changes over the years. We are also merging units with very small populations (less than 20,000 persons) with an adjacent unit that has similar population density and are within the same state. We are not taking mesoregions into consideration because mesoregions in Brazil are created for statistical purposes and are not administrative areas. At this stage our geography files for Brazil are work in progress, once complete we will be releasing states and municipios that are consistent through time.

Hope this helps.


Thanks for your answer.

I am in the process of finalizing my paper. Do you have an approximative idea when this geographical harmonization will be achieved?

We are working on Brazil 1980, 1991, 2000, and 2010 censuses. If completed, the earliest we could release the harmonized geography and maps would be 2016 summer.


Thank you for your answer.

By the way, regarding the variable STRATA, I have identified in 1980 some households that belonged to the same stratum and yet to different non-neighbouring states such as Rio Grande do Sul and Goias.

I find it quite weird. Do you have any explanation for this?