Hazard assessment of debris-flow-prone watersheds in Cubatão, São Paulo State, Brazil

• Published in: Natural hazards (Dordrecht) Vol. 116; no. 3; pp. 3119 - 3138
• Main Authors: Veloso, Vinicius Queiroz, Reis, Fabio Augusto Vieira Gomes, Cabral, Victor, Zaine, José Eduardo, dos Santos Corrêa, Claudia Vanessa, Gramani, Marcelo Fischer, Kuhn, Caiubi Emmanuel
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-04-2023; Springer Nature B.V
• Subjects: Civil Engineering; Debris flow; Detritus; Earth and Environmental Science; Earth Sciences; Empirical models; Environmental Management; Gas pipelines; Geology; Geomorphology; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hazard assessment; Hydrogeology; Morphometry; Natural gas; Natural Hazards; Original Paper; Parameter estimation; Parameters; Petroleum pipelines; Runoff; Watersheds; Brazil; Serra do Mar; Hydrogeomorphic processes; Forensic geomorphological analysis; Magnitude; Empirical model
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-022-05800-2

In Brazil, research related to the occurrence and prevention of debris flows is incipient when compared to the extent of the impacts caused by the phenomena. There is a need for further studies that consider susceptibility and hazard, especially in areas that are environmentally and socioeconomically vulnerable. This study aimed at assessing debris-flow hazard in the Rio das Pedras watershed, in Cubatão (State of São Paulo, Brazil), based on a set of different physiographic parameters (geomorphological, morphometric, geological) and in the application of empirical models. The hazard assessment was based on: (1) the evaluation of the history of events in the region; (2) the identification of the geomorphic controlling factors; (3) the estimation of the magnitude of a potential event; and (4) the identification of the elements at hazard. The results show that a debris-flow event in Rio das Pedras would more severely impact the Anchieta Highway (SP-150), the gas pipeline GASAN, the oil pipeline OSSP and the districts Pinhal do Miranda and Cota 95. These results highlight the relevance of geomorphological and geological parameters when estimating the extent of debris runoff, which is essential when defining the hazard in a debris-flow-prone watershed.