Clarifying the hydrological mechanisms and thresholds for rainfall-induced landslide: in situ monitoring of big data to unsaturated slope stability analysis

Empirical and Physically Based Thresholds for the Occurrence of Shallow Landslides in a Prone Area of Northern Italian Apennines

“…Instead, if Fs stay higher than 1, shallow failures are not modeled (stable conditions). Some attempts were proposed to build up reliable physicallybased thresholds in some areas prone to shallow landslides, such as in Italian alpine catchments [26], catchments of the Central Italian Apennines [27], hilly catchments of Southern Italy [20,[28][29][30][31], western hilly and mountainous settings of United States [32], and Chinese areas susceptible to shallow landsliding [33,34].The main limitations of physicallybased thresholds are related to the most important disadvantages of the deterministic methods [35]: (i) requiring a significant amount of geotechnical, mechanical, and hydrological parameters for model simulation; and (ii) reconstructing the boundary conditions which represent, in the best way, the real soil and slope behaviors. Integration of meteorological measurements (e.g., rainfall) and hydrological soil parameters (e.g., pore-water pressure and water content) could help Water 2019, 11, 2653 3 of 28 in obtaining a better insight into the quantitative effects of antecedent soil conditions on the triggering mechanism of shallow landslides.…”

“…Integration of meteorological measurements (e.g., rainfall) and hydrological soil parameters (e.g., pore-water pressure and water content) could help Water 2019, 11, 2653 3 of 28 in obtaining a better insight into the quantitative effects of antecedent soil conditions on the triggering mechanism of shallow landslides. Thus, field monitoring allows us to improve the calibration of the physicallybased models used to reconstruct rainfall thresholds [23,[32][33][34].This paper aims to reconstruct and compare empirically and physicallybased rainfall thresholds for the occurrence of shallow landslides in a susceptible area of the Northern Italian Apennines (Figure 1). The main objectives of this work can be summarized as follows: (i) assessing empirical thresholds through the analysis of time series of rainfall data and of shallow-landslide inventories for the identification of the triggering and non-triggering events; (ii) calibrating a physicallybased model by the comparison between monitored and simulated soil hydrological parameters in correspondence of a test-site slope, which can be assumed to be representative of the typical geological, geomorphological, and environmental settings prone to shallow landsliding in the study area; (iii) assessing physicallybased thresholds through the application of the calibrated deterministic model in correspondence with the representative testsite for different rainfall events; (iv) comparing the two typologies of estimated thresholds and verifying their predictive capabilities through different inventories of occurred shallow landslides not used for the threshold reconstruction.…”

“…Instead, if Fs stay higher than 1, shallow failures are not modeled (stable conditions). Some attempts were proposed to build up reliable physicallybased thresholds in some areas prone to shallow landslides, such as in Italian alpine catchments [26], catchments of the Central Italian Apennines [27], hilly catchments of Southern Italy [20,[28][29][30][31], western hilly and mountainous settings of United States [32], and Chinese areas susceptible to shallow landsliding [33,34].…”

“…Integration of meteorological measurements (e.g., rainfall) and hydrological soil parameters (e.g., pore-water pressure and water content) could help Water 2019, 11, 2653 3 of 28 in obtaining a better insight into the quantitative effects of antecedent soil conditions on the triggering mechanism of shallow landslides. Thus, field monitoring allows us to improve the calibration of the physicallybased models used to reconstruct rainfall thresholds [23,[32][33][34].…”

An Experimental Study on the Hydromechanical Behaviours of the Evolution of Postearthquake Landslide Deposits

“…Understanding the evolution mechanism of shallow headward failure and rill erosion of earthquake-induced landslide deposits in the headwater valleys caused by heavy rainfall is key to developing an early warning system of postseismic debris flow disasters [12,13]. The study of rainfall-induced landslides is a fairly complex topic involving a multidisciplinary technology [14].…”