A unified description of two-phase geophysical mass movements: erosion, transportation, phase-separation and deposition
Event details
| Date | 12.05.2016 |
| Hour | 12:15 › 13:15 |
| Speaker | Dr. Shiva Pudasaini, University of Bonn |
| Location | |
| Category | Conferences - Seminars |
Talk given by prof. S. Pudasaini, Uni. Bonn, Germany
Erosion, transportation, phase-separation and deposition processes play critical role in controlling the landscape, its morphodynamics and bedform evolutions in connection to two-phase debris flow and particle transport in mountain slopes, channels, valleys and river beds. This results in completely different evolution of avalanche and debris-flow fan and morphodynamics.
Here, we propose two fundamentally new mechanisms. The first is called the separation-flux, that leads to strong phase-separation in debris flows. This extends the general two-phase mass flow model (Pudasaini, 2012) by including a separation-flux mechanism that is capable of controlling the dynamically evolving phase-separation, sediment sorting and levee formation in a real two-phase, three-dimensional particle-fluid transport.
Secondly, we propose a novel, mechanically consistent, two-phase, erosion-entrainment-deposition model capable of adequately describing these complex phenomena commonly observed in landslides, avalanches, debris flows and bedload transports. This is achieved by enhancing the general two-phase mass flow model by introducing a two-phase variably saturated erodible basal morphology. The adaptive basal morphology allows for the evolution of erosion-deposition-depths, incorporating the inherent physical processes, evolving basal morphology due to erosion-channeling-deposition and rheological changes of the flowing mixture.
The novel enhanced real two-phase model also allows for simulating fluid-run-off during the deposition process. Our models are validated with some observations of debris-flow and particle transport. So, the novel, unified and efficient method can be utilized as a comprehensive model for avalanche and debris-flow fan evolution with multiple depositions, focusing on the detailed and accurate prediction of debris flow paths and channels. Potentially, it can also be applied for the morphodynamics of rivers and deltas, even during floods and hyperconcentrated flows.
Bio: Since August 2010: Professor (Visiting) at the School of Science, Kathmandu University, Dhulikhel, Kavre, Nepal.
November 2009 - August 2010: Guest Professor of Applied Mathematics, School of Science and School of Engineering, Kathmandu University, Dhulikhel, Kavre, Nepal.
April 2007 - March 2009: Adjunct Member: a Scientific and Technological Adviser for Collaborative Works on Natural Hazards: University of Natural Resources and Applied Life Sciences, Department of Civil Engineering and Natural Hazards, Vienna, Austria.
Since August 2006: a Senior Research Scientist at the Department of Geodynamics/Geophysics, University of Bonn, Germany.
January 2006 - July 2006: Research fellow at the Institute and Laboratory of Geotechnics, Faculty of Civil Engineering and Geodesy, Darmstadt University of Technology, Germany with Prof. R. Katzenbach.
January 2004 to December 2005: Postdoctoral fellow at the Department of Mechanics, Darmstadt University of Technology, Germany.
October 2000 - December 2003: PhD student at the Department of Mechanics, Darmstadt University of Technology
Advisor: Prof. Kolumban Hutter, PhD/Cornell Uni.
Topic: Avalanche Dynamics: Mathematical Model, Experimental Validation and Numerical Simulation for Complicated and Real Topographies.
2000-2003: Doctor of Natural Sciences in Geophysical Fluid Dynamics from the Department of Mechanics, Darmstadt University of Technology, Germany, with Distinction.
1998-2000: Master of Natural Sciences in Industrial Mathematics from University of Kaiserslautern, Germany, with Very Good.
1992-1994: Master Degree in Mathematics from T. U., Kathmandu, Nepal, with First Class.
1989-1991: Bachelor Degree in Mathematics and Economics from T. U., Kathmandu, Nepal, with First Class.
1986-1988: Intermediate Degree in Mathematics, Economics and Geography from T. U., Kathmandu, Nepal, with First Class.
Place of Origin: Bhadrabas, Kathmandu, Nepal.
Erosion, transportation, phase-separation and deposition processes play critical role in controlling the landscape, its morphodynamics and bedform evolutions in connection to two-phase debris flow and particle transport in mountain slopes, channels, valleys and river beds. This results in completely different evolution of avalanche and debris-flow fan and morphodynamics.
Here, we propose two fundamentally new mechanisms. The first is called the separation-flux, that leads to strong phase-separation in debris flows. This extends the general two-phase mass flow model (Pudasaini, 2012) by including a separation-flux mechanism that is capable of controlling the dynamically evolving phase-separation, sediment sorting and levee formation in a real two-phase, three-dimensional particle-fluid transport.
Secondly, we propose a novel, mechanically consistent, two-phase, erosion-entrainment-deposition model capable of adequately describing these complex phenomena commonly observed in landslides, avalanches, debris flows and bedload transports. This is achieved by enhancing the general two-phase mass flow model by introducing a two-phase variably saturated erodible basal morphology. The adaptive basal morphology allows for the evolution of erosion-deposition-depths, incorporating the inherent physical processes, evolving basal morphology due to erosion-channeling-deposition and rheological changes of the flowing mixture.
The novel enhanced real two-phase model also allows for simulating fluid-run-off during the deposition process. Our models are validated with some observations of debris-flow and particle transport. So, the novel, unified and efficient method can be utilized as a comprehensive model for avalanche and debris-flow fan evolution with multiple depositions, focusing on the detailed and accurate prediction of debris flow paths and channels. Potentially, it can also be applied for the morphodynamics of rivers and deltas, even during floods and hyperconcentrated flows.
Bio: Since August 2010: Professor (Visiting) at the School of Science, Kathmandu University, Dhulikhel, Kavre, Nepal.
November 2009 - August 2010: Guest Professor of Applied Mathematics, School of Science and School of Engineering, Kathmandu University, Dhulikhel, Kavre, Nepal.
April 2007 - March 2009: Adjunct Member: a Scientific and Technological Adviser for Collaborative Works on Natural Hazards: University of Natural Resources and Applied Life Sciences, Department of Civil Engineering and Natural Hazards, Vienna, Austria.
Since August 2006: a Senior Research Scientist at the Department of Geodynamics/Geophysics, University of Bonn, Germany.
January 2006 - July 2006: Research fellow at the Institute and Laboratory of Geotechnics, Faculty of Civil Engineering and Geodesy, Darmstadt University of Technology, Germany with Prof. R. Katzenbach.
January 2004 to December 2005: Postdoctoral fellow at the Department of Mechanics, Darmstadt University of Technology, Germany.
October 2000 - December 2003: PhD student at the Department of Mechanics, Darmstadt University of Technology
Advisor: Prof. Kolumban Hutter, PhD/Cornell Uni.
Topic: Avalanche Dynamics: Mathematical Model, Experimental Validation and Numerical Simulation for Complicated and Real Topographies.
2000-2003: Doctor of Natural Sciences in Geophysical Fluid Dynamics from the Department of Mechanics, Darmstadt University of Technology, Germany, with Distinction.
1998-2000: Master of Natural Sciences in Industrial Mathematics from University of Kaiserslautern, Germany, with Very Good.
1992-1994: Master Degree in Mathematics from T. U., Kathmandu, Nepal, with First Class.
1989-1991: Bachelor Degree in Mathematics and Economics from T. U., Kathmandu, Nepal, with First Class.
1986-1988: Intermediate Degree in Mathematics, Economics and Geography from T. U., Kathmandu, Nepal, with First Class.
Place of Origin: Bhadrabas, Kathmandu, Nepal.
Practical information
- General public
- Free
Organizer
- Christophe Ancey
Contact
- Christophe Ancey