Anthropogenic Geomorphology and Flooding in Subway Infrastructure: The Jardim São Paulo Station (São Paulo, Brazil)

Abstract

Urbanization of geomorphological systems results in changes to landforms and surface materials, affecting the spatial patterns of hydromorphodynamic processes. In many cases, these changes increase the susceptibility to urban and river flooding, potentially affecting urban infrastructure and causing loss of life and socioeconomic damage. Jardim São Paulo metro station, located within the Jardim São Paulo stream watershed (São Paulo, Brazil), is an example of infrastructure affected by recurrent urban flooding. This study aimed to evaluate the influence of original and anthropogenic geomorphological variables on the generation of concentrated surface runoff and their relationship with flooding at the metro station. The research was based on the principles and methods of anthropogeomorphology, particularly the historical approach, retrospective geomorphological mapping, and the use of geoindicators. The results showed that, over approximately 90 years, urbanization led to a 38.6% increase in street-network density, the impermeabilization of 92.5% of the watershed, and the culverting of 100% of the drainage network, promoting the generation of concentrated surface runoff. Flooding at the station was associated with both concentrated surface flows and the station's internal morphology and geomorphological location within the watershed. Although meteorological conditions are relevant, they could not be fully assessed because of limitations in the available data. The findings highlight that extreme events affecting urban infrastructure result from the interaction between pre-urban geomorphological conditions and anthropogenic modifications, providing valuable insights for urban infrastructure planning and climate adaptation.