Due to historic and economic reasons, Brazilian population is irregularly distributed in the country's territory. Although this characteristic has been altered in recent decades with the migration to the interior of the Country, population is still very concentrated along the coast, where there are the greatest demographic densities.
Population distribution in the state territory is also not uniform. The axis that links Porto Alegre to Caxias do Sul constitutes the most populated area of the State. Regarding the total population, 66.7% of the state municipalities have less than 10 thousand inhabitants. There are 123 municipalities with population between 10 thousand and 50 thousand inhabitants. The municipalities with population between 50 thousand and 100 thousand inhabitants are 24. And, finally, the municipalities with population above 100 thousand are only 17 and concentrate 46.8% of the total population of the State.
The average demographic density in Rio Grande do Sul was 38 inhab/km² in 2010. Among the states of the South Region of Brazil it is the one with the lowest population density, but it is still above the Brazilian average, 22.4 inhab/km². The area with the highest demographic density is in the axis Porto Alegre-Caxias do Sul. Nineteen out of the 29 municipalities with demographic density above 200 inhab/km² are located in this axis, and seventeen are located in Porto Alegre Metropolitan Region (RMPA) and two in the Metropolitan Region of Serra Gaúcha.
On the other hand, there are areas of low population density in the State. These are located in the west range of Rio Grande do Sul and correspond to the regions of COREDEs Jacuí Centro, Campanha, Fronteira Oeste, Missões and Alto da Serra do Botucaraí and, further north, COREDE Campos de Cima da Serra. The average demographic density of these regions is less than 20 inhab/km². The other regions have an average above 20 inhab/km² up to 923 inhab/km².
Source: IBGE - Censos Demográficos