Precipitation and landslides correlation study to propose of critical operational thresholds in the Baixada Santista-SP region

• Grant number: 24/16888-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2025
• End date: October 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Rodolfo Moreda Mendes
• Grantee: Danail Tsvetanov Metodiev
• Host Institution: Centro Nacional de Monitoramento e Alertas de Desastres Nacionais (CEMADEN). Ministério da Ciência, Tecnologia e Inovação (Brasil). Cachoeira Paulista , SP, Brazil

Abstract

The main objective of this project is to propose critical rainfall thresholds as an operational tool for SAAD (Landslide Early Warning System) of CEMADEN, of the municipal Civil Defense and of the State of São Paulo. The critical rainfall thresholds applied to shallow landslides will be established at operational levels within the scope of SAAD of Cemaden. The proposition of critical thresholds will be based on the methods of Tatizana et al (1987), an adaptation of the method of Guidicini & Iwasa (1977) and Consoni et al (1918) which is practically based on the shared method of the GIDES (Natural Disasters Integrated Risk Management) project. The intention is to establish a series of critical rainfall envelopes in the triggering of shallow landslides for 9 municipalities in the Metropolitan Region of Baixada Santista. The fundamental basis of this doctoral project will be the updating, organization and processing of data on shallow landslide occurrences recorded in the REINDESC (Cemaden Flood and Landslide Event Database), from the municipal Civil Defense and SIDEC (Civil Defense Information System of the São Paulo State), correlating them with the accumulated precipitation indices recorded by the PCD (Data collection platforms) of the CEMADEN observational network. A series of periods will be considered (1h, 3h, 6h, 12h, 24h, 48h, 72h, 96h, 168h and 720h) from the time of occurrence of the occurrences for a period of 11 years starting in 2014. The triggering and preceding rainfall will be surveyed and evaluated. Rainfall without occurrence records will be treated as calibration data. The correlation analysis of these data will allow the proposition of critical thresholds for triggering and preparatory rain (total rain), as well as critical thresholds for immediate and preceding (effective) rain, considering the rate of reduction of water in the soil.