Glacier lake outburst floods - modelling process chains Yvonne Schaub, Christian Huggel, Wilfried Haeberli Department of Geography, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland Changes in high-mountain areas - changes in natural hazards
[email protected] EGU April 2013
Illustration of the processes involved in the process chain
Outlook
Proccesses covered by the following models:
Results show that for rock-/ice-avalanches, dam breach and outburst floods, only numerical, physically based models are able to provide the required information, whereas the impact wave can be estimated by means of physically based or empirical assessments. In a next step, these findings will be validated by means of the case study of a recent glacier lake outburst event at Laguna 513 in Carhuaz, Cordillera Blanca, Peru, where on April 11th 2010 an ice-avalanche of approx. 300’000m3 triggered an outburst flood which travelled 23 km to the city of Carhuaz.
New lakes are forming in high-mountain areas all over the world due to glacier recession. Often they will be located below steep, destabilized flanks and are therefore exposed to impacts from rock-/ice-avalanches. Several events worldwide are known, where an outburst flood has been triggered by such an impact. In regions such as in the European Alps or in the Cordillera Blanca in Peru, where valley bottoms are densely populated, these far-travelling, high-magnitude events can result in major disasters. For appropriate integral risk management it is crucial to gain knowledge on how the processes (rock-/ice avalanches - impact waves in lake - impact on dam - outburst flood) interact and how the hazard potential related to corresponding process chains can be assessed.
Worni et al, submitted
3D Numerical models (Volkwein et al 2011) Hualcán
Empirical equations (VAW 2008, Cannata et al 2012) Analytical investigations (Di Risio and Sammarco 2008)
Laguna 513
Numeric simulations (Ataie-Ashanti and Yavari-Ramshe 2011) Empirical model (Singh 1996) Mathematical models (Fread 1991) Erosions-based models (Faeh et al 2011)
Slope failure Climate
Ice-Avalanche: 3D numerical model
Damage potential
Empirical relationships (Hürlimann et al 2008) Simple flow routing models (Huggel et al 2003) 1D Models (Hungr and Evans 1996) 2D / 3D Numerical models (Hürlimann et al 2008)
Consequences
Impact wave Lake outburst
Glaciers Lakes
Carhuaz
Impact Wave: empirical equations 2D numerical model
Flood / Debris flow
Lakes use
Characteristics of involved hazard processes and input / output data of the models 1
Risk assessment of natural hazards Research in natural hazards so far has mainly concentrated on describing, understanding, modeling or assessing single hazardous processes. Some of the above mentioned individual processes are quite well understood in their physical behavior and some of the process interfaces have also been investigated in detail. Multi-hazard assessments of the entire process chain, however, have only recently become subjects of investigations.
3
Model types, which fit into the model chain
Landslide parameters, which influence the following characteristics of impact waves: Degree of impact Wave characteristic Wave motion Runup (Simao and Fernandes 2011)
Volume Impact velocity Density Front shape underwater av. velocity extend of unstable area landslide length
3
X X
(Panizzo et al 2005a)
X X
X
Our study aims at closing this gap and providing suggestions on how to assess the hazard potential of the entire process chain in order to generate hazard maps and support risk assessments. We analyzed different types of models (empirical, analytical, physically based) for each process regarding their suitability for application in hazard assessments of the entire process chain based on literature in order to answer the following questions: * What are the crucial characteristics of the hazard processes involved in the process chan and which models fit into the assessment scheme by adequatly describing the required input/output information? * Which is the most appropriate process chain modelling approach?
(Singh 1996, Worni et al 2012,Fread 1991)
Overtopping hydrograph
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X X X X X X X
X
Type of impact wave models, which require this information as input:
(Volkwein etal 2011,RAMMS DBF Manual, Hungr and McDougall2009)
(VAW 2008, Cannata et al20 12, Ataie and Yavari 2011, DiRisio and Sammarco 2008)
3D numerical models 3D numerical models 3D numerical models 3D numerical models 3D numerical models
empirical eq. / numerical sim. empirical eq. / numerical sim. / analytical inv. empirical eq. / numerical sim. empirical eq. / numericall sim. analytical investigations numerical sim. numerical sim. / analytical investigation
Type of impact wave models, which deliver the corresponding information as output:
Type of dam breach models, which require this information as input:
(VAW 2008, Cannata et al20 12, Ataie and Yavari 2011)
(Worni et al 2012, Singh 1996)
empirical eq. / numerical sim.
mathematical mod. / erosions-based num. model
Type of dam breach models, which deliver the corresponding information as output:
Type of outburst flood models, which require this information as input:
(Worni et al 2012, Singh 1996)
(Hürlimann et al 2008, RAMMS DBF Manual)
mathematical mod. / erosions-based num. model erosions-based num. model
Empirical relationships / 1D models / 2D/3D num. mod. 1D models / 2D/3D numerical models
5
Dam breach parameters, that influence outburst flood: (Fread 1991)
Overflow hydrograph Discharge characteristics
5
(Panizzo et al 2005a) (VAW 2008)
Type of landslide models, which deliver the corresponding information as output:
4
Impact wave parameters, that influence dam breach:
Aims of this study and research questions
Outburst flood: 2D numerical model
6
Outburst flood parameters, that define final hazard map:
Type of outburst flood models, which deliver the corresponding information as output:
(Hürlimann et al 2008)
(Hürlimann et al 2008, RAMMS DBF Manual)
Runout distance Innundated area Intesity
empirical relationships / simple flow routing /1D models / 2D/3D numerical models empirical relationships / simple flow routing / 2D/3D numerical models 2D/3D numerical models
References Ataie-Ashanti, B. and Yavari-Ramshe, S. (2011): Numerical simulation of wave generated by landslide incidents in dam reservoirs. Lansdlides 8. pp417- 432. Cannata, M., Marzocchi, R. and Molinari, M.E. (2012): Modeling of Landslide-generated Tsunamis with GRASS. Transactions in GIS 16(2). Pp. 191 - 214. DiRisio, M. and Sammarco, P (2008): Analytical modeling of landslide-generated waves. Journal of waterway, port, coastal and ocean engineering ASCE. 134(1). Pp53-60 . Faeh, R., Mueller, R., Rousselot, P., Vetsch, D., Volz, C., Vonwiler, L., Veprek, R. and Farshi, D. (2011): System Manuals of Basement, Version 2.1. Laboratory of Hydraulics, Glaciology and Hydrology (VAW). ETH Zurich. Available from http://www.basement.ethz.ch (access: 07.06.2012). Fread, D.L. (1991): BREACH: An erosion model for earthen dam failure. Huggel, C., Kääb, A., Haeberli, W. and Krummenacher, B. (2003): Regional-scale GIS-models for assessment of hazards from glacier lake outbursts: evaluation and application in the Swiss Alps. Natural Hazards and Earth System Sciences 3. pp. 647-662. Hungr, O. and Evans, S.G. (1997): A dynamic model for landslides with changing mass. In: Engineering Geology and Environment. Marinos, Koukis, Tsiambaos and Stoumaras (eds.). Balkema, Rotterdam. pp 719-724. Hungr, O. and McDougall, S. (2009): Two numerical models for landslide dynamic analysis. Computers and Geosciencies 35. pp 978-992. Hürlimann, M., Rickenmann, D., Medina, V. and Bateman, A. (2008): Evaluation of approaches to calculate debris-flow parameters for hazard assessment. Engineering Geology 102. pp. 152 - 163. Panizzo, A., DeGirolamo, P., DiRisio, M., Maistri, A. and Petaccia, A. (2005): Great landslide events in Italian artificial reservoirs. Natural Hazards and Earth System Sciences 5.pp. 733-740 RAMMS (2001): User Manual v1.4 Debris Flow. WSL-SLF. Pp. 110. Simao, J. and Fernandes, R. (2011): Large dam-reservoir systems: guidelines and tools to estimate loads resulting from natural hazards. Naural Hazards 59. pp. 57-106. Singh, V.P. (1996): Dam Breach modelling technology. In: Water Science and Technology Library (17), Kluwer academic publishers. Dordrecht / Boston / London. pp. 241. VAW (2008): Rutscherzeugte Impulswellen in Stauseen - Grundlagen und Berechnung. VAW Mitteilung 4257. 31. Juli 2008. pp 172. Volkwein, A., Schellenberg, K., Labiouse, V., Agliardi, F., Berger, F., Bourrier, F., Dorren, L.K.A., Gerber,W. and Jaboyedoff, M. (2011): Rockfall characterisation and structural protection - a review. Natural Hazards and Earth System Sciences, 11 pp 2617-2651. Worni, R., Stoffel, M., Huggel, C., Volz, C., Casteller, A. and Luckman, B. (2012): Analysis and dynamic modeling of a moraine failure and glacier lake outburst flood at Ventisquero Negro, Patagonian Andes (Argentina). Journal of Hydrology. 444-445. pp. 134-145. Worni, R., Clague, J.J., Huggel, C., Künzler, M., Schaub, Y. and Stoffel, M. (submitted): Extreme flow events in mountainous regions – advanced approaches to model processes and process chains. Earth-Science Reviews.
This study was funded by the Swiss National Science Foundation and UNISCIENTIA STIFTUNG within the framework of the National Research Programme 61 on sustainable water management.
