Urban (dis)similarities between Braga and Guimarães (1984-2016):

Spatio-temporal analysis of rhythm and growth modes based on the Landsat archive

Abstract

Urban evolution, a primary question of Urban Geography, has always been limited by the lack of continuous spatial-temporal data. Recently, this limitation has been overcome by the processing in Geographic Information System of sequential snapshots acquired by Remote Sensing. Therefore, we use the Landsat archive to reveal the (dis)similarities of the urbanization process (rhythm and modes) experienced by the municipalities of Braga and Guimarães between 1984 and 2016. The results show that, more than temporal (When?) or quantitatively (How much?), the urbanization process in the two municipalities presents spatial disparities (Where? and How?). The Landscape Expansion Index (LEI) highlights that more than 50% of urban growth occurs in contiguity with the pre-existing fabric. Infilling constitutes the second most important mode in Braga, but not in Guimarães, where this position is occupied by outlying growth. Consequently, in Braga the urban perimeter captures better the urbanization process than in Guimarães. Thus, LEI can make an important contribution to the understanding of diffuse urbanization, a territorial model constantly called banal, and that - due to such an assertion - has been ignored in relation to other problem-areas.