Alvioli M., Rossi M., Guzzetti F., 2015, Slope stability scaling laws within physically based models and their modifications under varying triggering conditions, IAEG XII, pp. 547–550, Torino, 15-19 Settembre, 2013,
URL: http://www.cnr.it/prodotto/i/273460

The appearance of scaling phenomena in rainfall-induced landslides has been observed by several authors, and discussed within variuos theoretical models. A few properties of landslides are known to exhibit a power-law functional dependence, as shown by a number of world-wide datasets, which is often interpreted as a signature of the occurrence of self-organized criticality. We show that the adoption of a complex, physically motivated model for rainfall infiltration and slope stability can reproduce fairly well the observations over a wide range of rainfall durations and intensities, accounting for most of the features exhibited by the datasets in a natural way. Namely, we reproduce within our approach the observed functional dependencies and the slope of the scaling laws of intensity-duration triggering thresholds for shallow landslides, and the observed distribution of landslide sizes. Our approach thus represent a substantial improvement with respect to simulations performed within simple models where the complexity of the problem is reduced to very few degrees of freedom. No attempt was made of fine-tuning the large number of physical parameters characterizing the soil, whose unknown values practically prevent the application of the model itself as a predicting framework. We conclude that our results corroborate the robustness of the adopted model, which for the first time is applied over a very large study area partitioned in many sub-basins, and suggest that it represent a valuable tool to be used in conjunction with existing statistical approaches for the assessment of the risk associated with the stability of slopes subject to substantial rainfall activity. Focusing on the intensity/duration dependence of rainfall thresholds for triggering shallow landslides, we analyze the response of the various sub-basins for different triggering conditions, and infer the response of the systems under different climatic scenarios.

Data from https://intranet.cnr.it/people/