Engineering Geology for Society and Territory - Volume 2 pp 1041-1044 | Cite as
Physically Based Rainfall Thresholds for Shallow Landslide Initiation at Regional Scales
In this work, a physically based model that allows for the evaluation of rainfall thresholds for shallow landslide initiation at regional scales is applied to a study area in central Italy. The model is able to consider unsaturated conditions in the soil volume, by taking into account separately the evolution of pore water pressure below the water table and in the vadose zone. Starting from the simplified hypothesis of infinite slope, a series of numerical simulations were conducted in parametric form for the solution of the Richards equation, generalized to the case of deformable soil and formulated in terms of dimensionless variables. For the application of the model, an extended database of physical and mechanical properties of the soils within the study area was created by collecting data from the archives of the Civil Protection Provincial Office, considering the results of about 2,000 site investigations. This allowed us to identify the functional dependence of the critical rainfall intensity on the duration of the event, the geometric characteristics of the slope, the mechanical properties of the soil and the initial pore pressure regime. The study also shows that results are not sensitive to the deformation parameters.
KeywordsRainfall thresholds Shallow landslides Unsaturated conditions
The financial support of the Project “PRIN 2011” funded by the Italian Ministero dell’Università e della Ricerca is gratefully acknowledged.
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