Rural depopulation and the decline of vernacular architecture: an analysis of physical vulnerability in Bragança district, Portugal

Depopulation in rural areas poses significant threats to the preservation of vernacular architecture, a key representation of a region's cultural and historical heritage. Across many rural regions of Southern Europe, depopulation has led to significant demographic and cultural shifts. In Portugal, this trend is evident in various interior regions, including the Bragança district where the population has decreased by approximately 47.4% between 1960 and 2021. Over the course of six decades, the district’s population has nearly halved, reflecting broader patterns of rural decline driven by urban migration, aging populations, and economic shifts.This study analyses the physical vulnerability of vernacular dwellings in the Bragança district, focusing on how population decline influences the risk of deterioration and loss. Using quantitative data from the National Institute of Statistics (INE) censuses from 1864 to 2021 for population data and from 2001 to 2021 for housing data. Adopting a methodology that enables a comparative and locally tailored evaluation, the study employs three vulnerability indicators: construction period, occupation form, and conservation state, as well as their combined effects. The results revealed that of the 22,877 dwellings identified as vernacular in 2001, only 18,212 remained by 2021, representing a loss of 20.4% over two decades. Furthermore, in 2021, around 23% of the remaining vernacular dwellings were vacant, while 14.2% were categorized as being in poor condition. These findings emphasize the crucial need for targeted preservation strategies, not only in Bragança but also in similar rural contexts facing depopulation and architectural decline across Southern Europe.