1. Engineering geological mapping procedures in data-scarce hillsides for shallow landslide assessments: Applications in southeastern Brazil
- Author
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Lázaro Valentim Zuquette, Aline Freitas da Silva, and Adriana Ahrendt Talamini
- Subjects
Infiltration (hydrology) ,GEOTECNIA ,Safety factor ,Failure probability ,Geology ,Landslide ,Grid cell ,Scale (map) ,Geologic map ,Shear strength (discontinuity) ,Geomorphology ,Earth-Surface Processes - Abstract
This paper shows the results obtained from a group of simple and basic procedures used to assess slope instability in terms of shallow landslides on data-scarce hillsides at the slope unit scale. The procedures are based on engineering geological mapping to obtain geological and geotechnical data and on an adapted Hovland 3D safety factor (SF3D) associated with a van Genuchten infiltration model to simulate the rainfall percolation. The procedures were applied on a data-scarce hillside in the Campos do Jordao municipality located in the Mantiqueira Mountains, Sao Paulo state, Brazil. This area was chosen because it is affected by shallow landslides due to a loss of shear strength when suction decreases or dissipates due to rainfall infiltration. The combined procedures permitted the total SF3Dto be obtained from the partial SF of each grid cell (considering 4 different rainfall events and quasi-saturation conditions) and the failure probability (SF3D All of these results verify that all the slopes and selected potential rupture surfaces are compatible with the occurrence of shallow landslides on December 31st, 1999/January 1st, 2000. Large-scale engineering geological mapping proved to be fundamental because it provided detailed mapping of the spatial arrangement and characterizations of the geological material, thereby permitting adequate definitions of the potential rupture surfaces and the adoption of geotechnical and hydraulic parameters to calculate the SF3D and the failure probability (SF
- Published
- 2021