Development of a GIS-based Open Source Simulation Tool for Modelling General Avalanche and Debris Flows over Natural Topography

• Applicants: Professor Dr.-Ing. Andreas Malcherek, since 1/2016; Professor Shiva P. Pudasaini, Ph.D.
• Subject Area: Geotechnics, Hydraulic Engineering ; Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography ; Physical Geography ; Theoretical Chemistry: Molecules, Materials, Surfaces
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 250431212

• Final Report Year: 2018

Final Report Abstract

We have utilized fundamentally new and physically based modeling and simulation methods suitable for general two-phase debris flows. We have presented several novel models by extending the two-phase debris flow model. This includes rock-ice avalanche model capable of performing dynamic strength weakening and internal mass/momentum exchanges. We have addressed several issues by presenting mechanical two-phase erosion and phase-separation models solving some long standing problems in mass flows. These novel models are capable of generating first-ever erosion-deposition patterns and phase-separation and levee formation in two-phase debris flows. We have conducted large number of experiments in a large-scale inclined chute with run-out and produced extensive data sets as required for validating two-phase mass flow model and our computational tool, r.avaflow. Ultrasonic and pressure sensors were utilized to measure the flow depth and normal force that enabled us to estimate the bulk density evolution. We conducted further experiments to investigate entrainment processes and showed that increased water content dramatically magnified erosion resulting in immediate debris flooding. The novel experimental results provided profound insights in to the relationship between material composition, grain size, friction and their effects on flow dynamics and deposition fans including entrainment. We have developed an innovative, user-friendly and very efficient open source computational software, r.avaflow, for routing two-phase mass flows from a release area down an arbitrary complex topography to a deposition. r.avaflow is well calibrated, physically constrained, robust and advanced computational tool. We are extending r.avaflow to include physics-based erosion/deposition and phase separation mechanisms. r.avaflow is being used internationally in different universities and public services for hazard mitigation, early warning and planning. We are continuously maintaining the web page of r.avaflow, and providing supports for the international users. We have validated r.avaflow with several complex natural events. Our results demonstrate the general ability of r.avaflow to reproduce the evolution of flow heights, velocities, travel times and volumes reasonably well.

Publications

• (2014): A two-phase mechanical model for rock-ice avalanches. Journal of Geophysical Research: Earth Surface 119(10): 2272-2290
  Pudasaini, S.P., Krautblatter, M.
  
• (2014): Dynamics of submarine debris flow and tsunami. Acta Mechanica 225(8): 2423-2434
  Pudasaini, S.P.
  
• (2015): Lie symmetry solutions for two-phase mass flows. International Journal of Non-Linear Mechanics 77: 325-341
  Ghosh Hajra, S., Kandel, S., Pudasaini, S.P.
  
• (2015): Multivariate parameter optimization for computational snow avalanche simulation. Journal of Glaciology 61(229): 875-888
  Fischer, J.-T., Kofler, A., Fellin, W., Granig, M., Kleemayr, K.
  
• (2015): r.randomwalk v1, a multi-functional conceptual tool for mass movement routing. Geoscientific Model Development 8: 4027-4043
  Mergili, M., Krenn, J., Chu, H.-J.
  
• (2016): A novel description of fluid flow in porous and debris materials. Engineering Geology 202: 62-73
  Pudasaini, S.P.
  
• (2016): Landslide-generated tsunami and particle transport in mountain lakes and reservoirs. Annals of Glaciology 57(71): 232-244
  Kafle, J., Pokhrel, P.R., Khattri, K.B., Kattel, P., Tuladhar, B.M., Pudasaini, S.P.
  
• (2016): Simulating glacial lake outburst floods with a two-phase mass flow model. Annals of Glaciology 57(71): 349-358
  Kattel, P., Khattri, K.B., Pokhrel, P.R., Kafle, J., Tuladhar, B.M., Pudasaini, S.P.
  
• (2016): Snow avalanche friction relation based on extended kinetic theory. Natural Hazards and Earth System Sciences 16: 2325-2345
  Rauter, M., Fischer, J.-T., Fellin, W., Kofler, A.
  
• (2017): A Generalized Quasi Two-phase Bulk Mixture Model for Mass Flow. International Journal of Non-linear Mechanics
  Pokhrel, P.R., Khattri, K.B., Tuladar, B.M., Pudasaini, S.P.
  
• (2017): How well can we simulate complex hydro-geomorphic process chains? The 2012 multi-lake outburst flood in the Santa Cruz Valley (Cordillera Blanca, Perú). Earth Surface Processes and Landforms
  Mergili, M., Emmer, A., Juřicová, A., Cochachin, A., Fischer, J.-T., Huggel, C., Pudasaini, S.P.
  
• (2017): On analytical solutions of a two-phase mass flow model. Nonlinear Analysis - Series B: Real World Applications
  Ghosh Hajra, S., Kandel, S., Pudasaini, S.P.
  
• (2017): Optimal systems of Lie subalgebras for a two-phase mass flow. International Journal of Non-Linear Mechanics 88: 109-121
  Ghosh Hajra, S., Kandel, S., Pudasaini, S.P.
  
• (2017): r.avaflow v1, an advanced open source computational framework for the propagation and interaction of two-phase mass flows. Geoscientific Model Development 10: 553-569
  Mergili, M., Fischer, J.-T., Krenn, J., Pudasaini, S.P.