Urban expansion and disaster exposure in the North Coast of São Paulo: A comparison between formal and informal settlements

Código

XXV-SBRH0352

Autores

Cassiano Bastos Moroz, Tobias Sieg, Annegret Thieken

Tema

07 - Cidades Sustentáveis e Gestão da Água

Resumo

The disaster on the North Coast of São Paulo, in February 2023, highlighted the high exposure of urban areas to climate-related hazards in the region, especially in informal settlements. This paper aims to investigate past and future trends of urban expansion in the region and how they relate to disaster exposure. We focused on the differences between formal and informal settlements. Past trends were identified with the statistical analysis of historical urban footprint maps and their intersection with selected spatial factors. Future trends were estimated by predicting the spatial probabilities of urbanization with a Random Forest model, validated with past urban growth patterns. Results indicated that informal settlements are more prone to be located at steeper slopes and shorter distances from rivers, thus highlighting their higher exposure to disasters. Also, formal settlements are much more frequent at shorter distances from the coastline, while informal settlements are concentrated along the Rio-Santos highway, the main road connection in the region. To further investigate future scenarios of disaster exposure, we are currently working on the integration of these analyses into a dynamic framework to simulate urban growth and segregation in São Sebastião.