Assessment of shallow landslide susceptibility using mathematical models: support on real-time hydrologic monitoring

Abstract

Serra do Mar is a fault scarp with steep slopes that are often affected by shallow landslides triggered by extreme rainfall. Most of these events result in casualties, considering both economic and environmental damages. Although it is very important to follow these processes, predicting them is not an easy task due to the complexity of the factors that control the slopes stability. Thus, the main objectives of this research are to: (a) assess the shallow landslides susceptibility using mathematical models in three basins of the Caraguatatuba municipality; (b) identify critical levels of rainfall and the geotechnical parameters that have major influence on causing landslides; (c) identify priority areas for real time hydrological monitoring and (d) develop a proposal for real-time hydrologic monitoring. The material and methods to be applied in order to elaborate the susceptibility maps will be based on high resolution DTM and geotechnical values collected in situ and applied in the SHALSTAB and TRIGRS mathematical models. Inventories of landslides scars will be conducted (e.g. location, geometry, area) to verify the rate of success of these models. Then, considering the best scenarios we intend to indicate priority areas for real-time hydrologic monitoring. The main results will be: (a) landslide susceptibility maps considering the spatial variability and distribution of soil properties; (b) critical rainfall thresholds for triggering shallow landslides; (c) detailed proposal (acquisition, storage and transmission) for real-time hydrologic monitoring for Caraguatatuba municipality. (AU)