Flood risk map from hydrological and mobility data: A case study in Sao Paulo (Brazil)

Cities increasingly face flood risk primarily due to extensive changes of the natural land cover to built-up areas with impervious surfaces. In urban areas, flood impacts come mainly from road interruption. This article proposes an urban flood risk map from hydrological and mobility data, considering the megacity of Sao Paulo, Brazil, as a case study. We estimate the flood susceptibility through the Height Above the Nearest Drainage algorithm; and the potential impact through the exposure and vulnerability components. We aggregate all variables into a regular grid and then classify the cells of each component into three classes: Moderate, High, and Very High. All components, except the flood susceptibility, have few cells in the Very High class. The flood susceptibility component reflects the presence of watercourses, and it has a strong influence on the location of those cells classified as Very High.

Automated summary

The article proposes a method for creating urban flood risk maps using hydrological and mobility data, with the megacity of Sao Paulo, Brazil, as a case study. By estimating flood susceptibility through the Height Above the Nearest Drainage algorithm and assessing potential impact through exposure and vulnerability components, the cells are classified into moderate, high, and very high categories. The flood susceptibility component, reflecting the presence of watercourses, plays a significant role in determining the location of cells classified as very high risk.