A model of mudflow propagation downstream from the Grohovo landslide near the city of Rijeka (Croatia)

Abstract. Mudflows regularly generate significant human and property losses. Analyzing mudflows is important to assess the risks and to delimit vulnerable areas where mitigation measures are required. The smoothed-particle hydrodynamics (SPH) model adopted here considers, in two phases, a granular skeleton with voids filled with either water or mud. The SPH depth-integrated numerical model (Pastor et al., 2009a) used for the present simulations is a 2-D model capable of predicting the runout distance, flow velocity, deposition pattern and the final volume of mudflows. It is based on mathematical and rheological models. In this study, the main characteristics of mudflow processes that have emerged in the past (1908) in the area downstream of the Grohovo landslide are examined, and the more relevant parameters and attributes describing the mudflow are presented. Principal equations that form the basis of the SPH depth-integrated model are reviewed and applied to analyze the Grohovo landslide and the propagation of the mudflow wave downstream of the landslide. Based on the SPH method, the runout distance, quantities of the deposited materials and the velocity of mudflow progression which occurred in the past at the observed area are analyzed and qualitatively compared to the recorded consequences of the actual event. Within the SPH simulation, the Newtonian rheological model in the turbulent flow regime and the Bingham rheological model were adopted and a comparison was made of the application of the Egashira and Hungr erosion law.

[1]  Oldrich Hungr,et al.  A model for the runout analysis of rapid flow slides, debris flows, and avalanches , 1995 .

[2]  S. Leroueil,et al.  The Varnes classification of landslide types, an update , 2014, Landslides.

[3]  Philippe Coussot,et al.  Numerical modeling of mudflows , 1997 .

[4]  Manuel Pastor,et al.  Depth Averaged Models for Fast Landslide Propagation: Mathematical, Rheological and Numerical Aspects , 2015 .

[5]  M. Pastor,et al.  A depth-integrated viscoplastic model for dilatant saturated cohesive-frictional fluidized mixtures: Application to fast catastrophic landslides , 2009 .

[6]  J. Monaghan.  Smoothed particle hydrodynamics , 2005 .

[7]  A. Cantelli.  Uniform Flow of Modified Bingham Fluids in Narrow Cross Sections , 2009 .

[8]  D. Varnes.  SLOPE MOVEMENT TYPES AND PROCESSES , 1978 .

[9]  A Sridharan,et al.  Mechanisms Controlling Volume Change Of Saturated Clays And Role Effective Stress Concept , 1973 .

[10]  Ž. Arbanas,et al.  Complex landslide in the Rječina valley (Croatia): origin and sliding mechanism , 2005 .

[11]  R J Fannin,et al.  An empirical-statistical model for debris flow travel distance , 2001 .

[12]  Nevenka Ožanić,et al.  Risk Identification and Land-Use Planning for Disaster Mitigation of Landslides and Floods in Croatia , 2013 .

[13]  M. M. Allam,et al.  Effect of Clay Mineralogy on Coefficient of Consolidation , 1998 .

[14]  N. Ozanic,et al.  Qualitative assessment of geohazard in the Rječina Valley, Croatia , 2006 .

[15]  R. Iverson,et al.  U. S. Geological Survey , 1967, Radiocarbon.

[16]  Huafeng Liu,et al.  Meshfree Particle Methods , 2004 .

[17]  M. Pastor,et al.  Depth integrated modelling of fast landslide propagation , 2011 .

[18]  J. Monaghan,et al.  SPH simulation of multi-phase flow , 1995 .

[19]  Larry D. Libersky,et al.  Smooth particle hydrodynamics with strength of materials , 1991 .

[20]  Ž. Arbanas,et al.  The origine of instability phenomena along the karst-flysch contacts , 2009 .

[21]  Richard M. Iverson,et al.  Granular avalanches across irregular three-dimensional terrain: 1. Theory and computation , 2004 .

[22]  Ž. Arbanas,et al.  The Croatian–Japanese Joint Research Project on Landslides: Activities and Public Benefits , 2013 .

[23]  J. Monaghan,et al.  Smoothed particle hydrodynamics: Theory and application to non-spherical stars , 1977 .

[24]  Kyoji Sassa,et al.  A Landslide Monitoring and Early Warning System Using Integration of GPS, TPS and Conventional Geotechnical Monitoring Methods , 2014 .

[25]  G. R. Liu,et al.  1013 Mesh Free Methods : Moving beyond the Finite Element Method , 2003 .

[26]  Manuel Pastor,et al.  A SPH Depth Integrated Model for Popocatepetl 2001 Lahar. , 2009 .

[27]  M. Pastor,et al.  Numerical simulation of debris flows with the 2D - SPH depth integrated model , 2009 .

[28]  J. N. Hutchinson.  General report: morphological and geotechnical parameters of landslides in relation to geology and hydrogeology : Proc 5th International Symposium on Landslides, Lausanne, 10–15 July 1988V1, P3–35. Publ Rotterdam: A A Balkema, 1988 , 1988 .

[29]  L. Cascini,et al.  SPH run-out modelling of channelised landslides of the flow type , 2014 .

[30]  Guirong Liu,et al.  Smoothed Particle Hydrodynamics: A Meshfree Particle Method , 2003 .

[31]  Experimental study on the entrainment of bed material into debris flow , 2001 .

[32]  J. Monaghan,et al.  A refined particle method for astrophysical problems , 1985 .

[33]  Eugenio Oñate,et al.  A mesh-free finite point method for advective-diffusive transport and fluid flow problems , 1998 .

[34]  J. N. Hutchinson,et al.  Undrained Loading, A Fundamental Mechanism of Mudflows and other Mass Movements , 1971 .

[35]  M. Quecedo,et al.  Simple Approximation to Bottom Friction for Bingham Fluid Depth Integrated Models , 2004 .

[36]  Pastor Manuel,et al.  Improvement of irregular DTM for SPH modelling of flow-like landslides , 2013 .

[37]  J. Monaghan,et al.  Kernel estimates as a basis for general particle methods in hydrodynamics , 1982 .

[38]  Huafeng Liu,et al.  Meshfree particle method , 2003, Proceedings Ninth IEEE International Conference on Computer Vision.

[39]  M. Pastor,et al.  A depth‐integrated, coupled SPH model for flow‐like landslides and related phenomena , 2009 .

[40]  Ž. Arbanas,et al.  A complex landslide in the Rječina Valley: results of monitoring 1998-2010 , 2011 .

[41]  L. Libersky,et al.  High strain Lagrangian hydrodynamics: a three-dimensional SPH code for dynamic material response , 1993 .

[42]  C. Ling,et al.  Granular-Flow Rheology: Role of Shear-Rate Number in Transition Regime , 1996 .

[43]  J. Monaghan.  Simulating Free Surface Flows with SPH , 1994 .

[44]  L. Lucy.  A numerical approach to the testing of the fission hypothesis. , 1977 .

[45]  N. Ozanic,et al.  Qualitative assessment of geohazard in the Rječina River Valley, Croatia , 2006 .

[46]  A. Ct.  Geotechnical properties in relation to grain-size and mineral composition: The Grohovo landslide case study (Croatia) , 2014 .

[47]  K. Takara,et al.  Possible Scenarios for Rjecina River Catchment -on the Example of Grohovo Landslide , 2011 .

[48]  CuomoSabatino,et al.  Interplay of rheology and entrainment in debris avalanches: a numerical study , 2014 .

[49]  S. Egashira,et al.  Experimental study on the entrainment of bed material into debris flow , 1999 .

[50]  M. Pastor,et al.  Runout and deposit morphology of Bingham fluid as a function of initial volume: implication for debris flow modelling , 2014, Natural Hazards.

[51]  J. N. Hutchinson,et al.  A review of the classification of landslides of the flow type , 2001 .

[52]  Mohamed Naaim,et al.  SPH-based numerical investigation of mudflow and other complex fluid flow interactions with structures , 2007 .