Exercise: guided tour

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1 Exercise: guided tour Yves Bühler & Lukas Stoffel Seminar in snow, slush- and debris flows RAMMS Demonstration, September 3 rd 2013, Longyearbyen, Norway Swiss Federal Institute for Forest, Snow and Landscape Research WSL WSL Institute for Snow and Avalanche Research SLF

2 RAMMS simulation sequence 1. Preparation of the input datasets 2. Generating a new project 3. Setting release area and release height 4. Forest information 5. Global parameters 6. Mu/Xi classification 7. Running the calculation 8. Visualization of the results 9. Interpretation of the results 10. Exporting the results

3 Dorfberg/Salezer Avalanche SLF

4 Salezer avalanche: occurs frequently as large wet snow avalanche in spring but also as dry snow avalanche in winter reaching the road, protected by a gallery, and even lake Davos.

5 DEM 5m (.ascii oder.txt) Input Data Map 1: swisstopo (.tif +.tfw) Aerial imagery swisstopo (.tif +.tfw) è you have to delete this datasets after the workshop 2013 swisstopo (JD100007)

6 Forest as ASCII or shapefile Release area as shapefile à conversion to RAMMS release shapefile

7 Set Preferences Preferences Exercise: Set the correct project preferences (directories)

8 RAMMS User Workshop, September 3 rd 7 th 2012, Davos, Switzerland

9 Exercise: Create New Project RAMMS Project wizard Choose useful simulation DEM and name FOREST files Project Boundaries Project Summary

10 Release area & release height (AVAL) Draw by hand (2D mode only) Import shapefile and conversion to RAMMS release shapefile Use help tools! (Slope, photography, field observations) Multiple release areas possible RAMMS User Workshop, September 3 th 7 th 2012, Davos, Switzerland

11 Draw manually Import a polygon shapefile Convert polygon shapefile to RAMMS release shapefile RAMMS User Workshop, September 3 th 7 th 2012, Davos, Switzerland

12 Specify release depth, view release area information RAMMS User Workshop, September 3 th 7 th 2012, Davos, Switzerland

Draw two new release areas choosing two different release heights and save them

13 Exercise: 1. Draw a realistic release area by hand (2D Modus!) 2. Choose the release height (e.g. 0.5m) and save the release area 3. Draw two new release areas choosing two different release heights and save them under a different name 4. Convert the prepared release are (file: release.shp) into a RAMMS release shapefile

14 Forest Influences friction parameters µ und ξ Draw by hand Import and convert shapefile Import ASCII file

15 Return period Global Mu / Xi parameters Volume category Influence the classification of the Mu und Xi values Influence the runout distance and speed of the simulated avalanche

values by hand but be careful: only if you know exactly what you

16 Friction parameters Mu & Xi Automated procedure: calibrated with measurements from Vallée de la Sionne Possibility to set the values by hand but be careful: only if you know exactly what you are doing RAMMS User Workshop, September 3 th 7 th 2012, Davos, Switzerland

17 RAMMS User Workshop, September 3 th 7 th 2012, Davos, Switzerland

18 Exercise: 1. Run an automated MuXi classification (set the global parameters first) 2. Results are visualized, switch between mu and xi. 3. Change the return period, volume category and forest cover and run the classification one more time (save it under a different name). How do the friction values change? flat open slope channeled gully

19 Calculation Domain Draw calculation domain Calculation time can be significantly reduced by: Reducing the calculatin domain Increasing the size of the grid cells (grid resolution)

20 Run simulation Run a simulation by defining all parameters

21 Exercise: 1. Run a first calculation using a calculation grid size of 25m 2. Based on the results of this calculation you can confine the relevant area draw a calculation domain 3. Run a calculation with a smaller grid size (e.g. 5m)

22 Visualization Animation Maximum values (flow height, velocity, pressure) Adapt display!

Interpretation Use tools (colorbar, point-info, profiles) Project log file: simulation stopped due to LOW FLUX (Project à Output Log File) Control: avalanche volume, release height, MuXi, calculation

23 Interpretation Use tools (colorbar, point-info, profiles) Project log file: simulation stopped due to LOW FLUX (Project à Output Log File) Control: avalanche volume, release height, MuXi, calculation order Draw line Profile Exercise: Point info 1. Visualize your results using different possibilities (flow height, velocity, pressure, max values.) 2. Check the plausibility of the results 3. Draw profile plots along and across the avalanche track, how big are the maximum pressures in the deposition area? 4. Compare the results of the different simulations (5m and 25m grid)

24 Export results Exercise: 1. Export the max values as 3D and 2D images 2. Export the gif-animation of the flow height 3. Export the results as ASCII grid and shapefile 3 1 2

25 Very important!!! RAMMS is a model and not the reality! Additional information needed: Historical events Field visits (vegetation, key spots etc.) Terrain assessment Climatology/weather conditions Scenarios Slope Angle è Expert decision

26 Longyearbyen, NO It is your turn now!

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