A simplified physically based coupled rainfall threshold model for triggering landslides

Abstract A number of rainfall threshold models for triggering landslides have been developed in either empirical or physical manner. The objective of an empirical rainfall threshold model is to establish a relationship between rainfall intensity and duration, which is a line on a log–log diagram, although the mechanism of the relationship following the power law is not yet well understood. The sufficiency of rainfall and landslide data is also a significant concern for empirical models. A simplified physically based rainfall threshold model is developed by coupling the Mohr–Coulomb law and Darcy's law based on the assumptions that the slope has an infinite length and that discrete water diffusion is physically based. The power-law mechanism for the relationship between rainfall intensity and duration for the initiation of a landslide is investigated using this physically based model. The rainfall threshold calculated with the model shows that the threshold follows the power law for short rainfall durations whereas it gradually tends towards a constant value for long rainfall durations. Case studies have shown that a plausible threshold for regions that lack sufficient landslide and rainfall data can be obtained via the model. The model is also applied to cases which occurred in regions geologically typical of Fujian Province, southeast China. The landslide distribution predicted by our model accords with the interpretation of high resolution satellite imagery, and this suggests that the proposed physically based model also effectively determines rainfall thresholds for triggering regional landslides.

[1]  Jonathan P. McKenna,et al.  Regional landslide-hazard assessment for Seattle, Washington, USA , 2005 .

[2]  M. Rossi,et al.  The rainfall intensity–duration control of shallow landslides and debris flows: an update , 2008 .

[3]  Birgit Terhorst,et al.  Slope stability modelling with SINMAP in a settlement area of the Swabian Alb , 2009 .

[4]  Pietro Aleotti,et al.  A warning system for rainfall-induced shallow failures , 2004 .

[5]  R. H. Clark,et al.  Introduction to hydrometeorology , 1966 .

[6]  Rex L. Baum,et al.  Modeling landslide recurrence in Seattle, Washington, USA , 2008 .

[7]  David G. Tarboton,et al.  The SINMAP Approach to Terrain Stability Mapping , 1998 .

[8]  N. Caine,et al.  The Rainfall Intensity - Duration Control of Shallow Landslides and Debris Flows , 1980 .

[9]  Diana Salciarini,et al.  Spatially distributed rainfall thresholds for the initiation of shallow landslides , 2012, Natural Hazards.

[10]  D. Fredlund,et al.  Soil Mechanics for Unsaturated Soils , 1993 .

[11]  Yang Hong,et al.  Evaluation of TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis)’s predictive skill for hurricane-triggered landslides: a case study in Macon County, North Carolina , 2011 .

[12]  Lorella Montrasio,et al.  A model for triggering mechanisms of shallow landslides , 2008 .

[13]  R. Valentino,et al.  Shallow landslides triggered by rainfalls: modeling of some case histories in the Reggiano Apennine (Emilia Romagna Region, Northern Italy) , 2012, Natural Hazards.

[14]  W. Z. Savage,et al.  TRIGRS - A Fortran Program for Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Analysis, Version 2.0 , 2002 .

[15]  F. Bell,et al.  Landslides associated with the colluvial soils overlying the Natal Group in the greater Durban region of Natal, South Africa , 2000 .

[16]  M. Rossi,et al.  Rainfall thresholds for the initiation of landslides in central and southern Europe , 2007 .

[17]  F. Fiorillo,et al.  Space–time prediction of rainfall-induced shallow landslides through a combined probabilistic/deterministic approach, optimized for initial water table conditions , 2013, Bulletin of Engineering Geology and the Environment.

[18]  Antonino Cancelliere,et al.  Derivation and evaluation of landslide-triggering thresholds by a Monte Carlo approach , 2014 .

[19]  Shou-Hao Chiang,et al.  Modeling the spatial occurrence of shallow landslides triggered by typhoons , 2014 .

[20]  Francesca Bozzano,et al.  Evaluation of landslide reactivation: A modified rainfall threshold model based on historical records of rainfall and landslides , 2008 .

[21]  R. Valentino,et al.  Rainfall-induced shallow landslides: a model for the triggering mechanism of some case studies in Northern Italy , 2009 .

[22]  Kunlong Yin,et al.  GIS-based landslide hazard predicting system and its real-time test during a typhoon, Zhejiang Province, Southeast China , 2014 .

[23]  S. Im,et al.  Predicting the rainfall-triggered landslides in a forested mountain region using TRIGRS model , 2010 .

[24]  M. Crozier.  Prediction of rainfall-triggered landslides: a test of the Antecedent Water Status Model , 1999 .

[25]  Thomas Glade,et al.  Applying Probability Determination to Refine Landslide-triggering Rainfall Thresholds Using an Empirical “Antecedent Daily Rainfall Model” , 2000 .

[26]  Samuele Segoni,et al.  Rainfall thresholds for the forecasting of landslide occurrence at regional scale , 2012, Landslides.

[27]  Richard M. Iverson,et al.  Landslide triggering by rain infiltration , 2000 .