Full text - ITC

108 Pages·2009·19.99 MB·English

Snow avalanche runout modelling in Solang -
Dhundi area of Manali, Himachal Pradesh,
India, using a numerical model (RAMMS)

ANAND MALIK

January, 2009
Snow avalanche runout modelling in Solang–Dhundi
area of Manali Himachal Pradesh, India, using a
numerical model (RAMMS)

by

ANAND MALIK

Thesis submitted to Indian Institute of Remote Sensing (IIRS) and International Institute for Geo-
information Science and Earth Observation (ITC) in partial fulfilment of the requirements for the Joint
Master of Science degree in Geoinformation Science and Earth Observation, with specialization in
Geohazards

Thesis Supervisors:
ITC IIRS
Dr C. J. Van Westen Praveen K. Thakur
Thesis Advisors:
SLF SASE
Marc Christen, SLF Snehmani, SASE

Thesis Assessment Board:
Chairman: External Examiner:
Dr C. J. Van Westen Dr D. S. Arya, IIT, Roorkee
IIRS Member:
Dr V.Hari Prasad

iirs

INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH
OBSERVATION, ENSCHEDE, THE NETHERLANDS
&
INDIAN INSTITUTE OF REMOTE SENSING, NATIONAL REMOTE SENSING CENTRE
(NRSC), DEPARTMENT OF SPACE, DEHRADUN, INDIA
I certify that although I may have conferred with others in preparing for this assignment, and drawn
upon a range of sources cited in this work, the content of this thesis report is my original work.
Signed …………………….

Disclaimer

This document describes work undertaken as part of a programme of study at the Indian Insti-
tute of Remote Sensing, Dehradun, India and the International Institute for Geo-information
Science and Earth Observation, ITC, The Netherlands. All views and opinions expressed therein
remain the sole responsibility of the author, and do not necessarily represent those of the insti-
tute.

ANAND MALIK
Acknowledgements________

I believe that to be an effective teacher one must also be an effective learner, which is why I continue
to develop and challenge myself. Any kind of research need disciplined hard work, patience and sacri-
fice. Joining this course and the spending time with many scholars of their fields in India and abroad at
this juncture of my carrier was memorable and a benchmark in gaining knowledge in a field which was
completely new to me. The present work is out come of this and could have not been completed with-
out help, assistance and support from them.
I am thankful to my organisation, University of Delhi, Delhi and specially then Principal, SSN College
(University of Delhi), Dr J.L. Bhatt, for allowing and providing me study leave to do this M.Sc course.
Thanks are due to Dr V.K. Dadhwal, Dean, IIRS for providing all the necessary facilities required for
the course and research work. His expert opinion and technical guidance have proved to be precious
and valuable.
I express my sincere thanks and gratitude to Dr Cess J.Van Westen, who not only supported my idea
for working in this field i.e. avalanche, but extended each and every support whenever it was needed
to achieve my research aspiration. His detailed comments on the draft version the thesis were highly
informative and I appreciate his efforts to look into minute details. And I tried my best to justify the
required work..
Thanks are due to Mr. Praveen K. Thakur, for advising me all through thesis and directing me at every
step. He had been always energetic and inspiring for me to achieve the goal.
I thank, Marc Christen, SLF, Davos, Switzerland, who has developed RAMMS (Rapid Mass
movements) and provided academic version model used for present study. I benefited from his
knowledge since my proposal stage, about the dynamic modelling and application issues. Long discus-
sions with him were intense and fruitful and advanced the quality of my work.
Thanks are due to Dr Snehmani, Deputy Director, SASE, Chandigarh, for being advisor for this thesis
and providing all facilities from SASE and especially for sharing his field knowledge for this present
study.
The support and encouragement from both the course coordinators Dr Hari Prasad in IIRS and Drs
Michiel Damen in ITC are unforgettable. They have managed this course professionally and deserve
utmost respect. Thank you to both of you.
Thanks and gratitude is due to Dr Perry Bertelt, head of research unit ‘Avalanche, Debris Flows and
Rockfalls’; Dr Betty Sovilla, head of ‘Avalanche research group’ and Dr Lukas Stoffel, for extending
me every help needed while visit to SLF and spending their valuable time in teaching the fun-
damentals of the avalanche modelling and its scope for future research.
I thank, Byron Quan Luna at ITC, for long discussions about the thesis and his support in final editing
reviewing phase of this thesis.
I take this opportunity to show gratitude to all my batch mates in both the courses (Geohazards and
Geoinformatics) with whom I had spend unforgettable time at IIRS and ITC.
I thank Mr Ram Singh, an employee with SASE who is also called as the ‘walking encyclopaedia of
Manali avalanches’ in SASE, took me around the Solang - Dundhi area and give me the first hand
knowledge about the avalanches in the area.
Thank are also due to my family, my wife Renuka, son Akhil (Akki) and daughter Aishwarya
(Khushi), without their support this work would have never been possible. They have made sacrifice
part for my studies for spending one and half year away from me.
Last but not least I thank SLF, Switzerland and ITC, The Netherlands for funding my trip to SLF and
ITC to meet my Guides and to learn the model in October, 2008. The fellowship provided is greatly
appreciated.

ANAND MALIK
Dehradun,
January, 2009
ABSTRACT__

Snow avalanches are hazardous phenomena which affect settlements, transportation corridors,
tourists’ movements, natural vegetation and which disrupt the normal life in mountainous areas. For
reducing their impact, a better and accurate understanding of this phenomenon is required. In conven-
tional snow avalanche studies, various models, including empirical ones, were employed, which pro-
duced avalanche hazard maps based on historical information, generally on 1:50,000 scale maps. The
avalanche hazard maps, thus prepared, are lacking detailed information about velocity and impact of
snow avalanches. With recent advances in the field of rheology of flowing snow and the mechanics of
entrainment and deposition, dynamic modelling can now be applied to fulfil this gap. This coupled
with field observations and historical records can facilitate in better understanding of avalanche flow
mechanisms.
The main objective of this study was to investigate the applicability of the two dimensional snow ava-
lanche simulation model RAMMS (Rapid Mass Movements), developed by the Swiss SLF, in data
scarce environments in the Indian Himalayas. The research intended to parameterize the RAMMS
model with limited data, to evaluate the model sensitivity, to calibrate the model with very limited his-
torical avalanche information, and apply the model in sites where no historic information is available,
also for simulating future changes in hazard scenarios.
RAMMS is designed as a practical tool for avalanche engineers. It solves the depth - averaged equa-
tions governing avalanche flow with first and second order numerical solution schemes. RAMMS with
its Graphical User Interface (GUI) has been applied to a series of registered avalanches in the Solang -
Dhundi area in HP, India to evaluate the model performance.
The model was initially applied on the registered avalanche site MSP-7 to adjust both the friction val-
ues μ(Mu) and ξ (Xi) and to calibrate the model with the observed data. The model sensitivity was
conducted to calculate the most sensitive parameter. RAMMS was then run on the other avalanche
sites of the study area to find out the information about maximum height, velocity, pressure on the
road which further can be utilised for the land use planning and to generating the avalanche hazards
maps. It can be concluded from the study that RAMMS, once calibrated and validated, can be applied
to the other avalanche sites which are having similar physical and meteorological conditions and
where there less information about the avalanche events are available.

Keywords: Avalanche runout, avalanche dynamics, release area, RAMMS, numerical modelling, wet
snow avalanche.
Contents__________________________

1. Introduction....................................................................................................................................1
1.1. Background.............................................................................................................................1
1.2. Problem statement...................................................................................................................3
1.3. Aims and Objectives...............................................................................................................4
1.3.1. Research Questions.............................................................................................................4
1.4. Thesis structure.......................................................................................................................5
2. Literature Review...........................................................................................................................6
2.1. Avalanche phenomena............................................................................................................6
2.1.1. Slope Failure in Snow Environment...................................................................................7
2.1.2. Avalanche path...................................................................................................................8
2.1.3. Avalanche classification...................................................................................................11
2.2. Overview of Research works................................................................................................12
2.3. Snow Avalanche studies in India..........................................................................................14
2.4. Runout Modelling of Avalanches.........................................................................................14
2.4.1. Statistical models..............................................................................................................15
2.4.2. Dynamic avalanche modelling.........................................................................................17
2.5. Snow Flow Hazards Analysis and zoning.............................................................................20
2.5.1. Avalanche hazard zoning used throughout world............................................................22
3. THE RAMMS Model...................................................................................................................23
3.1. Introduction...........................................................................................................................23
3.1.1. The basic assumptions of the model.................................................................................24
3.1.2. Model characteristics........................................................................................................24
3.2. Governing differential equations..........................................................................................24
3.3. Model input...........................................................................................................................26
3.4. Model output.........................................................................................................................28
4. Study Area....................................................................................................................................29
4.1. Overview of study Area........................................................................................................29
4.2. Physiography........................................................................................................................30
4.3. Drainage................................................................................................................................30
4.4. Geology.................................................................................................................................31
4.5. Climate..................................................................................................................................31
4.6. Landuse.................................................................................................................................33
4.7. Over view of the avalanche site MSP 7................................................................................34
5. Methodology and Model parameterization................................................................................35
5.1. Data.......................................................................................................................................35
5.1.1. Data preparation...............................................................................................................36
5.1.2. Image rectification............................................................................................................37
5.2. Parameterization of model....................................................................................................38
5.2.1. Digital Elevation Model (DEM).......................................................................................38
5.2.2. Release zone.....................................................................................................................39
5.2.3. Friction Values.................................................................................................................43
5.2.4. Fracture Depth (snow height)...........................................................................................45
5.3. Methodology.........................................................................................................................47
5.4. Calibration of the model.......................................................................................................48
6. Validation and sensitivity analysis..............................................................................................50
6.1. Sensitivity analysis...............................................................................................................50
6.2. Parameter selection...............................................................................................................50
6.2.1. Sensitivity to the Turbulent Flow Factor ξ (Xi) parameter...............................................50
6.2.2. Sensitivity to the Coulomb Friction, μ (Mu) parameter...................................................53
6.3. Sensitivity to snow depth (fracture depth) and pixel size (DEM).........................................58
6.4. Validation..............................................................................................................................59
6.5. Model run on the avalanche sites MSP 4,5,6 where there is no historical information is
available :...........................................................................................................................................60
7. Conclusions and Recommendations...........................................................................................62
7.1. Results from Sub objectives:................................................................................................62
7.2. Results from the research questions......................................................................................63
7.3. Limitations of study..............................................................................................................64
7.4. Recommendations.................................................................................................................65
References:............................................................................................................................................66
Appendix 1: A detailed overview of the avalanche sites in the study area......................................71
Appendix 2: Various dynamic models used around the world........................................................81
Appendix 3: Avalanche hazard zoning (world).................................................................................92
Appendix 4 Derived parameters from RAMMS on MSP 7 (right side)..........................................94
Appendix 5 Release area derived from RAMMS using semi-automatic procedures.....................96
List of Figures_____________________
Figure 1: Relationship between geomorphic environment and man........................................................1
Figure 2: Snow avalanche hazards areas for central Asia (Nadim, Kjekstad et al. 2006) and in NW
India (Ganju and Dimri 2004)..................................................................................................................2
Figure 3: Annual fatalities due to avalanche accidents in the Himalayas (Ganju and Dimri 2004).........3
Figure 4: Relationship of avalanche science with other sciences.............................................................7
Figure 5: Deformation components of the snowpack (McClung and Schaerer 1993).............................8
Figure 6: Simplified conceptual model showing how numerous variables interact to determine snow
stability (Birkeland 1997).........................................................................................................................8
Figure 7: The principal classes of avalanche paths (Nickolaevich and Semionovich 1998; McClung
and Schaerer 2006)...................................................................................................................................9
Figure 8: A generalised Avalanche path...............................................................................................10
Figure 9: General Snow avalanche classification (according to type of release)...................................11
Figure 10: Loose and slab snow avalanche (McClung and Schaerer 2006)...........................................12
Figure 11: Slab avalanche release: Plan view and Elevation view (Mears 1992)..................................12
Figure 12: Schematic representation of the modelling process (Barnsley 2007)...................................14
Figure 13: Classification of Avalanche Models.....................................................................................15
Figure 14: Terrain parameters used in calculations of a statistical model (McClung and Mears 1991).
................................................................................................................................................................16
Figure 15: Schematic view of the flow zone and the runout zone after (Faug, Naaim et al. 2004).......18
Figure 16: General input and output features of dynamics models (Mears 1992).................................19
Figure 17: Procedure for identification and assessment of the avalanche hazard (Sovilla 2004)..........20
Figure 18: Graphical visualization of module (GUI) of RAMMS.........................................................23
Figure 19: Voellmy-Salm model / equation...........................................................................................26
Figure 20: Input and output of RAMMS................................................................................................26
Figure 21: Creating a new project input of the DEM and forest information in RAMMS....................27
Figure 22: Fracture depth and friction parameter in put in variable and constant mode in RAMMS....27
Figure 23: RAMMS output results depicting the maximum flow height. A cross-section line profile
plot shows the maximum flow height on the road (red line)..................................................................28
Figure 24: Location of study area..........................................................................................................29
Figure 25: Drainage map of Manali Sub Basin......................................................................................30
Figure 26: Geology of the study area (Sharma and Anand 1978)..........................................................31
Figure 27: Weather station (Dhundi)......................................................................................................32
Figure 28: Meteorological conditions over Dhundi for last 10 years (1990-2001)................................33
Figure 29: Land use and forest cover of the study area..........................................................................34
Figure 30: MSP 7 with a view of left and right side gullies and sub gullies..........................................34
Figure 31: Generation of DEM and Orthoimage in Lieca LPS..............................................................38
Figure 32: DEMs of different resolution of the study area....................................................................39
Figure 33: Grid configuration used in RAMMS for calculation of slope and curvature........................41
Figure 34: Generation of slope and curvature of MSP 7 to MSP 10 in RAMMS..................................42
Figure 35: Finding the PRAs using automatic procedures in RAMMS of the study area.....................42
Figure 36: Release areas of avalanche sites from RAMMS using automated procedures.....................43
Figure 37(a): Generation of coulomb friction map of the study area.....................................................44
Figure 38: Meteorological conditions on the avalanche day in Bahang and Dhundi weather stations
(February 1, 2004)..................................................................................................................................45
Figure 39: Schematic representation of the methodology adopted for the study...................................47
Figure 40: Calculation of deposition using the flow depth as the 5.5 meters (MSP 7)..........................49
Figure 41: Calibration of model with input values from SASE.............................................................49
Figure 42: Simulation with variation in Xi values.................................................................................51
Figure 43: Simulation with variation in Mu parameter..........................................................................53
Figure 44: Comparative analysis between minimum and maximum Mu and Xi values........................55
Figure 45 (a): Relation between Xi Vs Max velocity on the Road........................................................55
Figure 46: Relation between snow depth and flow height on the road..................................................56
Figure 47: Snow height and flow height on the road on different DEMs..............................................57
Figure 48: simulating the avalanche event occurred on MSP 3 on February 9, 2004 and validating with
data available (data source: SASE, Chandigarh)....................................................................................59
Figure 49: Model run over the MSP 4, 5, 6 where no historical information is available.....................60
Figure 50: Max velocity (above) and Max pressure (below) on the road..............................................61