Monitoring Geological Risk Areas in the City of Sao Paulo Based on Multi-Temporal High-Resolution 3D Models

Author(s)

de Sousa, Amanda Mendes ; Viana, Camila Duelis ; Garcia, Guilherme Pereira Bento ; Grohmann, Carlos Henrique

• Document type: Journal article
• Source: REMOTE SENSING; v. 15, n. 12, p. 19-pg., 2023-06-01.

Abstract

This paper presents a multi-temporal comparison of high-resolution 3D digital models from two urban areas susceptible to landslides in three time periods. The study areas belong to the Sao Paulo landslide risk mapping database and are named "CEU Paz" (CP) and "Parque Santa Madalena I" (PSM). For each area, a lidar digital surface model (DSM) (2017) and two structure-from-motion multi-view stereo DSMs (2019 and 2022) built from drone imagery were combined using raster algebra to generate three digital surface models of differences (DoDs). The DoDs were able to highlight changes in vegetation cover and buildings, which are important characteristics for evaluating geological risks in an urban context. Still, they were unable to highlight changes in the ground surface. The results demonstrate that the method greatly supports monitoring, allowing for greater detail and ease of detecting large-scale changes. Even with promising results, this technique should be understood as one more tool for mapping risk areas without replacing fieldwork. (AU)

• FAPESP's process: 19/26568-0 - High-resolution remote sensing, deep learning and geomorphometry in analyses of mass movements and geological risk
• Grantee: Carlos Henrique Grohmann de Carvalho
• Support Opportunities: Regular Research Grants