Python-FALL3D: User manual - a procedure for modelling volcanic
Contents
1. cd lt home gt lt username gt lt tephra gt lt volcano gt 22 Python FALL3D User Manual UN MC j PA Elevation m Probability exceeding 0 1 kg m 96 4808 51 63 Roads Probability exceeding 0 1 kg m MEN 64 75 O Town E 76 88 306 INDIAN OCEAN Plabuhanratu Elevation m Probability exceeding 90 kg m Probability exceeding 90 kg m 13 25 bes 63 75 es O Town 306 Figure 4 Example python FALL3D probabilistic multiple wind volcanic ash hazard maps for various load thresholds A 0 1 kg m significant damage to crops NOTE contours are truncated by the limits of the modelled domain B 90 kg m cosmetic damage to building exteriors 23 Python FALL3D User Manual Elevation m Ash thickness m 4808 E 1 2 Roads Ash thickness m B O Town B 306 ON Elevation m Ash concentration kg m 4808 0 1 6e 6 3e 7 8e Roads I 1 7e4 3 1e E 7 9e 9 3e O Town 3 2e 4 7e al 9 4e 1 1e 4 8e 6 26 306 El 2x Bod RUS Ash concentration kg m Figure 5 A Example python FALL3D volcanic ash thickness map m based on a forecast wind profile B Example python FALL3D volcanic ash concentration in the atmosphere map kg m based on a forecast wind profile 24 Python FALL3D User Manual Acknowledgements The author gratefully acknowledges technical c2. This resource is intended for geoscientists and natural hazard modellers who have a volcanological and or geological background but no or limited computer programming background Python FALL3D User Manual 2 Background The distribution and thickness of volcanic ash deposited during mildly to highly explosive volcanic eruptions has important life safety livelihood economic and political implications for densely populated areas that are affected A number of computational modelling tools have been developed in recent decades for forecasting the transport and deposition of volcanic ash Geoscience Australia undertook a study to test and assess existing volcanic ash hazard computational models and evaluate each of these models for different purposes 1 e single scenario probabilistic forecasting Volcanic ash hazard computational models could be loosely classified into two main groups based on their intended application 1 Advection diffusion models which describe particle diffusion transport and sedimentation and can simulate volcanic ash fallout at ground level relative to an eruptive source e g HAZMAP TEPHRA FALL3D and ASHFALL 2 Particle tracking models which can simulate volcanic ash cloud height and extent at specific times e g PUFF HYSPLIT and VAFTAD 2 1 FALL3D An existing advection diffusion sedimentation model has been trialled and adapted for use in South East Asia in response to the needs of government agencies an
3. 6 1 BUILDING A VOLCANIC ASH MODELLING AREA 1 Open a new terminal 2 Change directory into your sandpit cd lt sandpit gt 3 To create a modelling area type mkdir lt volcanic_ash_modelling gt A directory named volcanic ash modelling has now been created in the sandpit and is ready to be populated with python scripts from the templates directory 6 2 TEMPLATE SCRIPTS The templates directory contains example scripts which the user can copy into their modelling area edit and run as needed There are three template scripts l extract windprofiles py create wind profiles Table 1 2 volcano py run FALL3D Table 2 3 create hazard maps py create probabilistic hazard map Table 3 To copy these scripts to the modelling area 1 Open a new terminal 2 Change into the directory cd lt sandpit gt aim templates 3 To view a list of the template scripts type Is 1 4 To copy these scripts into a new modelling area type cp py lt sandpit gt lt volcanic_ash modelling directory gt All files with the extension py will be copied into the volcanic ash modelling area specified by the user These files can then be opened edited and run as needed Python FALL3D User Manual To confirm that the modelling area has been populated with the three template scripts 1 Open a new terminal 2 Change into the directory cd lt sandpit gt lt volcanic_ash_modelling gt 3 Type Is 1 A list of templa
4. Connor C B B E Hill B Winfrey N M Franklin and P C LaFemina 2001 Estimation of volcanic hazards from tephra fallout Natural Hazards Review 2 33 42 Costa A G Macedonio and A Folch 2006 A three dimensional Eulerian model for transport and deposition of volcanic ashes Earth and Planetary Science Letters 241 3 4 634 647 Folch A and Costa A 2010 FALL3D 6 2 User Guide http www bsc es projects earthscience fall3d 15 pp Goodwin J and Bear Crozier A N in prep Volcanic ash hazard modelling using python FALL3D The 1994 eruption of Tavurvur East New Britain Province Papua New Guinea Geoscience Australia Record Heffter J L and B J B Stunder 1993 Volcanic Ash Forecast Transport and Dispersion Vaftad Model Weather and Forecasting 8 4 533 541 Hurst A W and R Turner 1999 Performance of the program ASHFALL for forecasting ashfall during the 1995 and 1996 eruptions of Ruapehu volcano New Zealand Journal of Geology and Geophysics 42 4 615 622 Legros F 2000 Minimum volume of a tephra fallout deposit estimated from a single isopach Journal of Volcanology and Geothermal Research 96 25 32 25 Python FALL3D User Manual Macedonio G M T Pareschi and R Santacroce 1998 A numerical simulation of the Plinian fall phase of 79 AD eruption of Vesuvius Journal of Geophysical Research Solid Earth and Planets 93 B12 14817 14827 Newhall C G and Self S 1982 The vol
5. Height of the eruption column Empirically derived suzuki parameter for the position of neutral buoyancy with respect to column height The greater the value for A the higher the mass sits in the simulated column Units m Options point suzuki or plume Units kg s Options number or estimate Units m Options number or estimate Suzuki Only Options values typically between 1 and 4 where 1 Strombolian and 4 Plinian Python FALL3D User Manual height_or MFR MFR_minimum MFR_maximum exit_ velocity exit_ temperature exit volatile fraction FALL3D Empirically derived suzuki parameter for the spread of mass within the column with respect to the neutral buoyancy level The greater the value for L the more horizontally dispersed across the column the mass will be The plume model only requires the user to enter a column height height or a mass eruption rate MFR It will calculate the other independently Minimum mass eruption rate Maximum mass eruption rate Magma exit speed Magma exit temperature Volatile fraction what percentage of the melt is H20 CO etc Suzuki Only Options values typically between 1 and 5 where 1 Plinian and 5 Strombolian Plume only Options height or MFR Plume only Units kg s Plume only Units kg s Plume only Units m s Plume only Units K Plume only Units This section is w
6. PARAMETER Cale Pactor 0 9906 EARAMBPIERI ThatrLude Or One rn 0 0 AUN ET Meter Fy 21 Python FALL3D User Manual Appendix 2 Preparing meteorological data 1 Navigate to the website http www esrl noaa gov psd data reanalysis 2 Select from the list of dot points The 6 hourly and daily data currently available on line 3 Select from the list of blue dot points Pressure Level The current webpage is for extracting NCEP Reanalysis data at multiple pressure levels for a the domain There are 4 variables that need to be downloaded Air temperature Geopotential Height U wind and V wind There are three options for each variable 4 times daily daily and monthly mean Python FALL3D uses the four times daily data not daily or monthly 4 Click on the coloured map for Air Temperature 4 times daily to open a new webpage 5 Click on the coloured map Make a plot or subset to select the region for download 1 e Indonesia Philippines PNG etc to open a new webpage 6 Under Axis Dimensions enter the coordinates for the region that you would like to download NCEP data for e g Indonesia lat begin 20N lat end 10S lon begin 95E lon end 160E 7 Under Other dimension values s select 1000 00 millibar from the pressure level list Hold down the shift button on your keyboard and select all the other pressure levels right down to 10 millibar this means you would li
7. you will require the following e A standard PC with at least 4GB of RAM and an Ubuntu Linux operating system see http www ubuntu com for instructions on downloading and setting up Ubuntu Linux freely available and e An internet connection for initial download and installation only unless specified 4 1 DOWNLOADING DEPENDENCIES Seven dependency programs are required for python FALL3D to run successfully The user must configure Ubuntu s Synaptic manager so that it will be able to locate and install these programs internet connection required prior to installing python FALL3D 1 Open Ubuntu Linux and ensure an internet connection is established 2 Select System from the toolbar menu and then select Administration and then Synaptic Package Manager to open a new window 3 Select the tab labelled Repositories and tick all the box options if not already checked 4 Close Synaptic Package Manager 4 Select Applications from the toolbar menu and the select Accessories and then Terminal to open a new terminal Follow this procedure whenever a new terminal is needed 5 To download the first dependency program called subversion type sudo apt get install subversion 6 Press Enter Subversion will be downloaded and installed automatically 7 Repeat this procedure for the 6 remaining dependency programs listed below sudo apt get install python numpy sudo apt get install py
8. 2 simulates the fallout of volcanic ash during explosive volcanic eruptions It is used to understand how volcanic ash interacts with the surrounding atmosphere and where it is deposited at ground level The purpose of this manual is to introduce a user with no programming or computational modelling experience to FALL3D Version 6 2 using software called python FALL3D Python FALL3D was developed jointly by Geoscience Australia GA the Australia Indonesia Facility for Disaster Reduction AIFDR Badan Geologi BG and the Philippines Institute of Volcanology and Seismology PHIVOLCS Python FALL3D features a series of python scripts around the core dispersion model FALL3D Version 6 2 which simplifies the modelling procedure The manual features step by step instructions for installing and running simulations of volcanic ash fallout using python FALL3D for deterministic single scenario probabilistic multiple wind and forecasting purposes 1 2 SCOPE This manual provides instructions for installing and running python FALL3D in a Unix Linux environment It incorporates step by step instructions for creating volcanological meteorological and topographic input files running an eruptive scenario and viewing the results The package includes two example scenarios based on historical volcanic eruptions in Indonesia which will familiarise new users with the modelling procedure and test if the installation procedure has been successful 1 3 AUDIENCE
9. Australian Government AUSTRALIA INDONESIA Geoscience Australia FACILITY FOR PHIVOLCS DISASTER REDUCTION Python FALL3D User Manual A procedure for modelling volcanic ash hazards Adele Bear Crozier Record GeoCat PIN ny dk ANA ION ANI 71843 UND M oe J AN j AS S Ld ns O Bandua p PES f E PEN Pr ra n ur Em m US Q9 T P A y 1 3 AR i A BN yy 3 f i cw tE APPLYING GEOSCIENCE TO AUSTRALIA S MOST IMPORTANT CHALLENGES Python FALL3D User Manual A procedure for modelling volcanic ash hazards GEOSCIENCE AUSTRALIA RECORD 2011 33 By Adele Bear Crozier Australian Government E sad Geoscience Australia 1 Geoscience Australia Geospatial and Earth Monitoring Division Risk and Impact Analysis Group Department of Resources Energy and Tourism Minister for Resources and Energy The Hon Martin Ferguson AM MP Secretary Mr Drew Clarke Geoscience Australia Chief Executive Officer Dr Chris Pigram Commonwealth of Australia Geoscience Australia 2011 With the exception of the Commonwealth Coat of Arms and where otherwise noted all material in this publication is provided under a Creative Commons Attribution 3 0 Australia Licence http creativecommons org licenses by 3 0 au Geoscience Australia has tried to make the information in this product as accurate as possible However it does not guarantee that the information
10. FALL3D volcanic ash load kg m map based on a single wind profile B Example python FALL3D volcanic ash thickness map m based on a single wind profile Note contours are truncated by limits of the modelled domain 21 Python FALL3D User Manual 10 Open create hazard map py using a text editor by typing gedit create hazard maps py 11 Edit the input variables Table 3 12 Save and close To run type python create hazard maps py Outputs files are generated for each ash load threshold PLOADI PLOAD2 etc in ASCII grd shp and kml Google Earth format Figure 4 To view output files navigate to the TEPHRADATA area cd lt home gt lt username gt lt tephra gt lt volcano gt 8 3 FORECASTING This procedure details how to run a volcanological scenario using forecasted wind data produced by the BoM ACCESS T meteorological model Python FALL3D downloads a 24 hour forecast converts it into a compatible format and runs the fallout model for a projected 24 hour period a forecasting approach 1 Open volcano py using a text editor by typing cedit volcano forecast py 7 Edit the input variables Table 2 Appendix 3 8 Rename the script when saving and close e g merapi py 9 To run type python lt volcano gt py eg python merapi py Outputs files are generated for each simulated hour in ASCII grd shp and kml Google Earth format Figure 5 To view output files navigate to the TEPHRADATA area
11. This procedure details how to run a volcanological scenario using multiple wind fields extracted from NCEPl renalysis meteorological data a probabilistic approach The results of each scenario are merged into a single hazard map showing probability of exceeding a user defined volcanic ash load threshold kg m Multiple hazard maps can be generated for multiple ash threshold values 1 Open a new terminal 2 Navigate to your volcanic ash modelling directory cd lt sandpit gt lt volcanic_ash_modelling gt 3 Open extract windprofiles py using a text editor by typing gedit extract windprofiles py or use preferred editor 4 Edit the input variables Table 1 5 Save and close To run type python extract_windprofiles py 6 Open volcano py using a text editor by typing gedit volcano py 7 Edit the input variables Table 2 Appendix 3 8 Rename the script when saving and close e g merapi py The script can be run in serial one computer or in parallel multiple nodes Appendix 5 9 To run the script serially type python volcano multiple wind py eg python merapi multiple wind py 20 Python FALL3D User Manual INDIAN OCEAN Elevation m Ash load kg m 4808 0 0 05 1 2 Roads Ash load kg m Eo B O Town Eques go B 306 ONESIA Sy Elevation m 4808 Roads Ash thickness m O Town 306 Figure 3 A Example python
12. ager the user is still required to run the model from a UNIX command line using a terminal window The user is therefore required to know a number of basic UNIX commands There are eight commands which are particularly useful when for navigating through a UNIX environment using python FALL3D cd directory name gt change directory Open this directory cd go up one directory Close this directory and open the parent directory cd J go up two directories Keep adding to go up more than two directories Is l list Display contents of current directory pwd print working directory Display current location cp lt filename gt lt directory gt copy this file and move it to this directory cp lt extension gt lt directory gt copy all files with this extension and move them to this directory mkdir lt directory gt make directory Make a new directory folder at this location this is followed by a space and the name of the new directory Other commands that the user may require to use python FALL3D include svn co checkout Refers to checking out a repository scripts etcetera python This is then followed by a space and the name of the python script that the user would like to run In s link Allows you to create a shortcut to a specified directory from the current directory Python FALL3D User Manual 4 System requirements amp dependencies To run python FALL3D
13. ation about how many processes can run independently on each node For more details on hostfiles see e g http linux die net man 1 mpirun or http www open mpi or 24 Python FALL3D User Manual Appendix 6 Glossary of volcanological and meteorological terms Point Mass of an eruption column is released at a single source point Folch and Costa 2010 Suzuki Mass of an eruption column released according to an empirically derived formula Folch and Costa 2010 Plume Mass of an eruption column released according to the buoyant plume theory Folch and Costa 2010 Rams Constant horizontal Equations for solving the horizontal diffusion co efficient of settling particles Folch and Costa 2010 Similarity Constant vertical Equations for solving the vertical diffusion co efficient of settling particles Folch and Costa 2010 ARASTOOPUR Mathematical formula for estimating the settling velocity of particles Folch and Costa 2010 GANSER Mathematical formula for estimating the settling velocity of particles Folch and Costa 2010 WILSON Mathematical formula for estimating the settling velocity of particles Folch and Costa 2010 DELLINO Mathematical formula for estimating the settling velocity of particles Folch and Costa 2010 33
14. cano explosivity index VEI An estimate of explosive magnitude for historical volcanism Journal of Geophysical Research 87 C2 1231 1238 Pyle D M 1989 The thickness volume and grainsize of tephra fall deposits Bulletin of Volcanology 51 1 1 15 Searcy C K Dean and W Stringer 1998 PUFF A high resolution volcanic ash tracking model Journal of Volcanology and Geothermal Research 80 1 2 1 16 Sulpizio R 2005 Three empirical methods for the calculation of distal volume of tephra fall deposits Journal of Volcanology and Geothermal Research 145 3 4 315 336 26 Python FALL3D User Manual Appendix 1 Template for preparing digital elevation data 1 DEM File Format nools 59 nrows 64 xlLicorner 4124372 33001039 yllcorner 9SIOOTUSO272T79 cellsize 1000 NODATA Value 9999 300 O47 2330920 4990 2d 0 204 dad 1469 4206 546 575 576 6064 990 779 1 9 L4 950 964 931 973 LOS Pied 127354 1366 14 20 L962 L380 Lol 420 ESO P2906 1095 980 924 636 189 Foi 0659 6045 545 SLY 4264 432 205 393 Bolt Bon 790 2 Projection File Format PROJCS WGS 1984 UTM Zone 485 GEOGCS GCS WGS 1984 DATUM D WGS 1984 SPHEROID WGS 1984 6378137 0 pL 90 29712799025 1 ERIMEMI Greenwrxch 0 O UNITIUDeogree 0 01749552925199432 ls EROJECTION E Transverse Me EEALoOr PARAMETER False basting y 900000 D0 pL PARAMETER balse Noruhring L00000004 0 4PARAMETER Centra l Merpdran 750 530
15. ckness_units mm cm m 30 Python FALL3D User Manual Appendix 4 Range table The range table below details the acceptable range of eruption column heights eruption column increments mass eruption rates and eruption durations that should be adhered to when considering a new scenario The table is based on the volcano explosivity index VEI Newhall and Self 1982 Ranges VEI 2 VEI 3 VEI 4 VEI 5 VEI 6 VEI 7 VEI 8 Eruption 2000 5000 3000 15000 10000 25000 25000 30000 30000 50000 30000 50000 50000 column height m Eruption 1000 1000 10000 10000 10000 10000 10000 10000 column height Increments m Mass eruption 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 1x10 rates kg s Eruption 1 6 1 6 1 6 6 12 gt 12 gt 12 gt 12 duration hours Increments must always be the same magnitude of order as the eruption column height i e 3 000m 1 000 increments 40 000m 10 000 increments 31 Python FALL3D User Manual Appendix 5 Running in parallel multiple nodes The command below shows an example host file for a cluster with 20 dual cpu quad core nodes 1 e 8 processes can run on each node mpirun x FALL3DHOME x PYTHONPATH hostfile etc mpihosts host node lt gt node lt gt python lt volcano gt py A host file for the system must be specified for this command to work The file must contain the names of each computer node in the system along with inform
16. d emergency managers in this region This model is the widely used open source volcanic ash hazard model FALL3D Version 6 2 FALL3D was developed jointly between the Instituto Nationale Geofiscia Vulcanologia INGV Italy and Barcelona Supercomputing Centre BSC Spain FALL3D solves the advection diffusion sedimentation equation which governs the settling of ash particles through the atmosphere during a volcanic eruption including aspects of ground level thickness load and distribution It is able to model the transport and deposition of volcanic ash at ground level during an explosive volcanic eruption It has the ability to model the dispersal of volcanic ash in a wind field that experiences changes in wind speed direction and air temperature with altitude and over time FALL3D also considers the interaction between topography and the meteorological conditions and the impact this may have on dispersal of ash at ground level 2 2 PYTHON FALL3D A SIMPLIFIED USER INTERFACE A Python wrapper was developed jointly between Geoscience Australia GA and the Australia Indonesia Facility for Disaster Reduction AIFDR which modifies the modelling procedure of FALL3D to simplify its use for those with no background in computational modelling Three modelling procedures are available through a unified interface scenario based modelling single event hazard mapping probabilistic wind and forecasting predictive Python FALL3D outputs are geospatia
17. del results navigate to TEPHRADATA cd lt home gt lt username gt lt tephra gt guntur1840 5 Compare model output with stored model output for the Guntur 1840 eruption located in the directory below and shown in Figure 1 cd lt sandpit gt aim validation guntur reference_data model_ouputs Elevation m 4808 306 Ash thickness cm Jo ES 1 2 EE ng s 10 BH E 25 E gt E gt INDIAN OCEAN 25 Roads Ash thickness cm O auntur 1840 75 O 50 Town 100 A Volcano Figure 1 Stored model output for the 1840 eruption of Gunung Guntur showing good agreement with observed ash thicknesses collected at 16 localities White points measured observed ash thicknesses cm from G Guntur N Kartadinata Black lines ash thickness cm isopach map generated by FALL3D Pink ash distribution thickness in cm generated by FALL3D used to construct isopach map Python FALL3D User Manual 5 3 2 Validation Scenario 2 1994 eruption Tavurvur Volcano Papua New Guinea This scenario was developed to validate FALL3D against observed ash thicknesses from the 1994 eruption of Tavurvur Volcano East New Britain Papua New Guinea by James Goodwin GA and Adele Bear Crozier GA Goodwin and Bear Crozier in prep Modelled outputs were compared against ash thickness observations collected within the nearby township of Rabaul destroyed during the eruption published by Blong and McKee 1995 and Blo
18. hen prompted with update bashrc file Y or N type Y The installation of python FALL3D is complete The location of the output data is controlled by the environment variable called TEPHRADATA It is specified in the system file named bashrc in your home directory If you want the output data to be stored elsewhere you can edit the bashre file using the following procedure 9 Open a new terminal and navigate to your home directory Python FALL3D User Manual 10 Type gedit bashre or use your preferred editor 11 The bashre file will open 12 Scroll down to the line export TEPHRADATA lt home gt lt username gt lt tephra gt 13 Customise the pathway for output data to be stored when using python FALL3D The default will be lt home gt lt username gt lt tephra gt and this will be used for all future reference to the TEPHRADATA area throughout this manual 14 Save and close the terminal window Note It 1s important to close this terminal window to ensure that the environment variables set by the installation process come into effect 5 2 TESTING PYTHON FALL3D There is a script called test_all py which will test if the installation was successful To run the script 1 Open a new terminal 2 Change to the directory cd lt sandpit gt aim testing 3 To run the test script type python test_all py 5 3 VALIDATION SCENARIOS Python FALL3D has been validated against a number of historical erupt
19. here the user sets the parameters for volcanic ash dispersal through the atmosphere following the initial eruption FALL3D uses one of three terminal velocity models for the settling over volcanic ash through the atmosphere the possibilities are ARASTOOPOR GANSER WILSON and DELLINO Appendix 6 terminal velocity model vertical turbulence model horizontal turbulence model vertical diffusion coefficient Model for volcanic ash settling through the atmosphere Vertical turbulence experienced by the ash particles can be user defined CONSTANT or derived from the wind profile SIMILARITY Horizontal turbulence experienced by the mass in the column can be user defined CONSTANT or derived from the wind profile RAMS Mixing of particles vertically within the simulated eruption column Options ARASTOOPOR GANSER WILSON and DELLINO Options CONSTANT and SIMILARITY Options CONSTANT or RAMS If vertical turbulence is CONSTANT then CONSTANT else RAMS Only defined by user if vertical and horizontal turbulence is CONSTANT else derived from wind profile i e SIMILARITY RAMS Options High column 1 50 and Low column 50 1000 Python FALL3D User Manual horizontal diffusion coefficie Mixing of particles Only defined by user if vertical nt horizontally within the and horizontal turbulence is si
20. ions in order to ensure the modelled outputs accurately reproduce observed ash thickness and loads Two validation scenarios are included with the installation of python FALL3D the 1840 eruption of Gunung Guntur Indonesia and the 1994 eruption of Tavurvur Volcano Papua New Guinea It is important that users run each validation and compare the generated outputs with stored model outputs included in reference data as part of the python FALL3D installation This serves to familiarise the new user with the modelling procedure and verify that the installation of python FALL3D works as intended 5 3 1 Validation Scenario 1 1840 eruption of Gunung Guntur Indonesia This scenario was developed to validate python FALL3D against observed ash thicknesses from the 1840 eruption of Gunung Guntur The scenario was developed by Nugraha Kartadinata BG Anjar Heriwaseso BG Adele Bear Crozier GA Ole Nielsen AIFDR Antonio Costa INGV Arnau Folch BSC and Kristy Van Putten AIFDR at a workshop held at the AIFDR in Jakarta in July 2010 Modelled outputs were compared against observed volcanic ash thickness measured in the field at Gunung Guntur by N Kartadinata and internal BG publication Python FALL3D User Manual To run the 1840 Gunung Guntur validation scenario 1 Open a new terminal 2 Change to the directory cd lt sandpit gt aim validation guntur 3 To run the Guntur 1840 scenario type python guntur1840 py 4 To view mo
21. is totally accurate or complete Therefore you should not solely rely on this information when making a commercial decision ISSN 1448 2177 ISBN 978 1 921 954 36 8 Hardcopy ISBN 978 1 921 954 35 1 Web GeoCat 71843 Bibliographic reference Bear Crozier A N 2011 Python FALL3D User Manual A procedure for modelling volcanic ash hazards Geoscience Australia Record No 201 1 33 Python FALL3D User Manual Table of Contents l BECO IG GIO a acis MEME EMI l KERTET O E A AAE EE EE EE l AA A T P l Load NEE APRA Pe cates O A es repete de usta di duode l 2 lore durum TT 2 PA SUID O EIEEE M IA AOA O ONAE TEE EOE S EA E 2 2 2 Python FALL3D a simplified user interface norria enaa as eaaa a aaa a aaia 2 3 Usezub DNDSCODHIAHOS ita a pum ras ded oa tutum quad ibstum does mend ER dU qudd os M EM M DU 3 4 System requirements amp dependencies sees 4 4 1 Downloading dep 4 5 First time installation of python FALL3D ococccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnns 5 5 1 Installing python PAL ID it A A dolus 5 3 2 Testing Py MORA FALLS A AAA A det usto otn caret Po 6 S on adatto SCC Mall OS ati tii as 6 5 3 1 Validation Scenario 1 1840 eruption of Gunung Guntur Indonesia 6 5 3 2 Validation Scenario 2 1994 eruption Tavurvur Volcano Papua New Guinea 8 6 Setting pa modellin AI eo ERD 9 6 1 Building a volcanic a
22. ke air temperature data for every pressure level 8 Select the date you wish to download in UTC time 9 Under Output options select Create a subset without making a plot 10 Under Plot output options deselect Color plot 11 Select Create Plot or Subset of Data to open a new webpage 12 Select FTP copy of the file 13 Save the file when prompted 14 Return to the webpage with the first colour map Step 4 15 Repeat steps 4 14 for the three remaining variables Geopotential Height u wind and v wind 16 There should be 4 files with the extension nc at the conclusion of the download process 17 Rename the Air Temperature file TMP nc 18 Rename the Geopotential Height file HGT nc 19 Rename the u wind file UGRD nc 20 Rename the v wind file VGRD nc 21 Note the pathway to the directory where the files are stored for modelling purposes e g lt model_area gt lt tephra gt lt NCEP gt 28 Python FALL3D User Manual Appendix 3 Volcanological input worksheet Short eruption comment to appear in output directory eruption comment ZTemporal parameters eruption start Hours relative to the start of wind data eruption duration Hours post eruptive settling duration Hours to allow for ash settling Location x coordinate of vent UTM zone implied by projection y coordinate of vent UTM zone implied by projecti
23. lling procedures available to users of python FALL3D 1 Scenario based 2 Hazard Map and 3 Forecasting A description of each modelling procedure the necessary input data generated outputs and python scripts to be used are detailed in Table 4 8 1 SCENARIO BASED PROCEDURE This procedure details how to run a volcanological scenario using a single merged wind field extracted from NCEP 1 renalysis meteorological data a deterministic approach 1 Open a new terminal 2 Navigate to your volcanic ash modelling directory cd lt sandpit gt lt volcanic_ash_modelling gt 3 Open extract windprofiles py using a text editor by typing gedit extract windprofiles py or use preferred editor 4 Edit the input variables Table 1 5 Save and close To run type python extract_windprofiles py 6 Open volcano py using a text editor by typing gedit volcano py 7 Edit the input variables Table 2 Appendix 3 8 Rename the script when saving and close e g merapi py 9 To run type python lt volcano gt py eg python merapi py 18 Python FALL3D User Manual Table 4 Overview of python FALL3D modelling procedures input requirements outputs and python scripts Procedure Scenario based Hazard Map Forecasting Description A procedure used to model a volcanological scenario and a single merged wind profile This procedure is useful for deterministic modelling and is not computational
24. lly referenced in a standard format and can be viewed alongside other datasets important for impact and risk analysis such as population density exposure of the built environment and crop extents The hazard maps produced contour connecting points of equal volcanic ash thicknesses or ash load mass per unit area or ash concentration volume per unit area Each map may contain contours of volcanic ash thicknesses load that vary in appearance according to the volcanological and meteorological conditions during the eruption Collectively these hazard maps are intended for use by government agencies to assess the risk of volcanic ash for communities Validation of the underlying numerical model FALL3D against observed data from known historical eruptions in the South East Asian region was an important part of the two year development stage for python FALL3D Validation a measure of how accurately the model reproduces known volcanic ash deposits has important implications for the expected uncertainty in modelled outputs and the relative sensitivity of different input parameters 1 e wind speed versus ash grainsize FALL3D has been validated with a few specific examples from volcanic eruptions in Indonesia and Papua New Guinea Python FALL3D User Manual 3 Useful UNIX commands Python FALL3D is designed to run in a UNIX Linux environment such as Ubuntu Linux Although directories and output files can be viewed and manipulated through the windows man
25. lowing TMP nc HGT nc UGRD nc and VGRD nc NCEP dir lt home gt lt username gt lt tephra gt lt NCEP gt a directory containing NCEP files Path to directory of generated wind profiles This will indicate the pathway to the directory where the multiple wind profiles generated from the NCEP data will be stored windfield dir lt home gt lt username gt lt tephra gt lt merged gt a directory of merged profiles lt home gt lt username gt lt tephra gt lt multiple gt a directory of multiple profiles Wind field type option are merged or multiple wind field type This script can produce two types Scenario based merged of wind profiles depending on the Hazard Map multiple modelling procedure chosen Table 2 Description and input options where applicable for each input parameter in the python script volcano py Input parameter Description Units input options examples Short eruption comment to appear in output directory eruption comment Name of output directory added to timestamp Temporal parameters Hours The wind profile determines the time limit of the simulated eruption i e a 16 hour wind profile means the eruption can t exceed 16 hours The user must input the eruption start time relative to this wind profile in hours i e O eruption and wind begin together 1 eruption begins 1 hour after wind Python FALL3D User Manual eruption_start Start time of the e
26. ly intensive A procedure used to model a volcanological scenario and multiple wind profiles This procedure is useful for probabilistic assessments based on changing wind conditions but is computationally time consuming A procedure used to model a volcanological scenario with forecast wind data Input 1 DEM 2 Merged vertical wind profile NCEP1 3 Volcanological scenario 1 DEM 2 Multiple vertical wind profiles NCEP1 3 Volcanological scenario 1 DEM 2 Vertical wind profile ACCESS T 3 Volcanological scenario 19 Output Volcanic ash thickness mm cm m based on one historical wind profile Volcanic ash load kg m based on one historical wind profile Probability of exceedance 96 of a volcanic ash threshold value in kg m based on multiple historical wind profiles Volcanic ash thickness mm cm m based on a forecasted wind profile Volcanic ash load kg m based on a forecasted wind profile Python scripts 1 extract windprofiles py Table 1 2 volcano py Table 2 extract windprofiles py volcano py create hazard maps py Table 3 volcano py Python FALL3D User Manual Outputs files are generated for volcanic ash thickness and load each simulated hour in ASCII grd shp and kml Google Earth format Figure 3 To view output files navigate to the TEPHRADATA area cd lt home gt lt username gt lt tephra gt lt volcano gt 8 2 HAZARD MAPPING
27. mulated column CONSTANT else derived from wind profile i e SIMILARITY RAMS Options 1000 10000 value of CS A constant value between RAMS only 0 135 and 0 32 only used when horizontal turbulence is RAMS Contouring True False number or list of numbers Python FALL3D produces maps of volcanic ash thickness and volcanic ash load The model contours the ash thickness and load values for viewing in Google Earth kml and ArcGIS shp There are four options for determining the interval between contours True the model will determine equally spaced contours based on the spread of data a good first approximation False no contours Number the user can specify the number of contour intervals and the model will generate that number of contours based on the spread of data and List of Numbers the user can specific the number of contour intervals and the corresponding value for each interval user for a standardised classification scheme and comparing different scenarios thickness contours Type of contouring Options True False Number or List of Numbers load contours Type of contouring Options True False Number or List required for of Numbers volcanic ash load kg m thickness units Ash thickness units Units mm cm m Run model using specified parameters Procedure 2 Hazard Map only Refer to 7 2 Location of multiple wind fields for probabilistic hazard mapping and location of generated out
28. ng 2003 1 Open a new terminal 2 Change to the directory cd lt sandpit gt aim validation tavurvur 3 To run the Tavurvur 1994 scenario type python tavurvur py 4 To view model results navigate to TEPHRADATA cd lt home gt lt username gt lt tephra gt tavurvur 5 Compare model output with stored model output for the Guntur 1840 eruption located in the directory below and shown in Figure 2 cd lt sandpit gt aim validation tavurvur reference data model ouputs Y CORAL SEA BISMARK SEA Elevation m Ash thickness cm we es Bae Ash thickness cm Ej Mo O Town 10 20 E 80 100 A Volcano Roads 306 Figure 2 Stored model output for the 1994 eruption of Tavurvur Volcano showing good agreement with observed ash thickness isopach map produced by Blong and McKee 1995 black lines Python FALL3D User Manual 6 Setting up a modelling area Python FALL3D has now been successfully downloaded and installed The validation scripts have been run to test the success or failure of that installation process Each new user must now set up a volcanic ash modelling area This is the directory where the user will edit all scripts and run the model This volcanic ash modelling area will sit within the sandpit but separate from python FALL3D source code the test scripts and the validation scenarios the directory named aim You will only need to follow this step once for initial setup purposes
29. old value i e 0 1 or a list of thresholds values separated by commas and enclosed in square brackets i e 0 1 10 20 The resulting map s will contour probability of exceeding the ash load threshold in 9o Options a single threshold value i e 0 002 or a list of thresholds values separated by commas and enclosed in square brackets i e 0 0002 0 002 The resulting map s will contour probability of exceeding the ash concentration threshold in 9o The model contours probability of exceedance 96 and or change through time hour for viewing in Google Earth and ArcGIS There are four options for determining the interval between contours True False Number or List of numbers Refer to Table 2 ISOCHRON contours ISOCHRON units PLOAD contours PLOAD units Contour interval type Contour units Contour interval type Contour units Options True False Number or List of Numbers Units hours Options True False Number or List of Numbers Units percent Location of generated windprofiles hazard map and contours This directory should contain the multiple scenario outputs produced by volcano py which will be used to create the hazard map s The hazard map s will be stored here model output directory l lt home gt lt username gt lt tephra gt lt hazard_outputs gt a directory of multiple profiles Python FALL3D User Manual 3 Modelling Procedure There are three mode
30. on Vertical discretisation for model domain z min Z max Z_increment Meteorological input Refer to Table 2 wind_profile Path to wind data or online forecasts DEM model Refer to Table 2 topography_grid Path to topography file Granulometry grainsize_ distribution Possibilities are GAUSSIAN BIGAUSSIAN modal bimodal number_of_grainsize_classes mean_grainsize phi sorting minimum grainsize phi maximum grainsize phi density minimum kg m3 density_maximum kg m3 sphericity minimum sphericity maximum Source vent_height meters source_type Possibilities are plume suzuki point mass_eruption_rate kg s if unknown estimate height above vent m A suzuki only L suzuki only height or MFR plume only MFR minimum kg s plume only MFR maximum kg s plume only exit velocity m s plume only exit temperature K plume only exit volatile fraction plume only 29 Python FALL3D User Manual Fall3D terminal velocity model Possibilities are ARAsTOOPOR GANSER WILSON DELLINO vertical turbulence model Possibilities are CONSTANT SIMILARITY horizontal turbulence model Possibilities are CONSTANT RAMS vertical diffusion coefficient m2 s horizontal diffusion coefficient m2 s value of CS RAMS only Contouring thickness_contours if unknown True load_contours kg m2 thi
31. ontributions in the development of this manual made by but not limited to O Nielsen AIFDR N Kartadinata BG A Heriwaseso BG P J Delos Reyes PHIVOLCS H Mirabueno PHIVOLCS K Van Putten AIFDR A Folch BSC A Costa INGV and J Goodwin GA The author also acknowledges T Dhu AIFDR J Sexton GA and A Simpson GA for feedback provided during the development of this resource Finally the author would like to thank colleagues in Geoscience Australia for feedback provided on a draft of this manual References Barberi F G Macedonio M T Pareschi and R Santacroce 1990 Mapping the tephra fallout risk an example from Vesuvius Italy Nature 344 142 144 Blong R 2003 Building damage in Rabaul Papua New Guinea 1994 Bulletin of Volcanology 65 43 54 Blong R and McKee C 1995 The Rabaul eruption 1994 destruction of a town Natural Hazards Research Centre Macquarie University Sydney Bonadonna C and Houghton B F 2005 Total grain size distribution and volume of tephra fall deposits Bulletin of Volcanology 67 441 456 Carey S N and Sigurdsson H 1982 Influence of particle aggregation on deposition of distal tephra from the May 18 1980 eruption of Mount St Helens volcano Journal of Geophysical Research 87 B8 7061 7072 Carey S N and Sparks R S J 1986 Quantitative models of the fallout and dispersal of tephra from volcanic eruption columns Bulletin of Volcanology 48 109 125
32. puts one hazard scenario per wind field windfield directory l lt home gt lt username gt lt tephra gt lt multiple gt a directory of multiple profiles hazard output directory lt home gt lt username gt lt tephra gt lt hazard_outputs gt directory where multiple model runs are to be stored Python FALL3D User Manual Table 3 Description and input options where applicable for each input parameter in the python script create hazard map py Input parameter Description Units input options Vent location in geographic coordinates decimal degrees vent_easting vent_northing vent_zone vent_hemisphere Values Location of the vent Location of the vent UTM zone of the vent Hemisphere of the vent UTM coordinates UTM coordinates Options N or S Hazard maps are based on multiple scenarios and a specified threshold of volcanic ash kg m The resulting maps contour the probability of exceeding that specified ash threshold given the multiple scenarios One map is produced for each threshold value load values fl values Contours Volcanic ash load threshold values kg m which will be used to generate a hazard map A separate hazard map will be generated for each load value Volcanic ash concentration threshold values kg m which will be used to generate a hazard map A separate hazard map will be generated for each concentration value Options a single thresh
33. rdinates of the vent These coordinates will be used to extract a vertical wind profile s at a location closest to the vent using NCEP 1 reanalysis data from the National Oceanic and Atmospheric Association Appendix 2 vent_easting location of the vent UTM coordinates vent_northing location of the vent UTM coordinates vent_zone UTM zone of the vent vent hemisphere hemisphere of the vent Options N or S 11 Python FALL3D User Manual Time to start extraction The extraction start time indicates when the wind profile will begin and is usually the same time as he start of the eruption start_year start year of the wind profile YY YY start_month start month of the wind profile Options 1 2 12 start_day start day of the wind profile Options 1 2 31 start_hour start hour of wind profile Options 0 6 12 or 18 Time to end extraction The extraction end time indicates when the wind profile will end and must be at least one hour after the post eruptive settling duration to ensure all the simulated volcanic ash has been deposited at ground level See Table 2 end_year end year of the wind profile YYYY end_month end month of the wind profile Options 1 2 12 end_day end day of the wind profile Options 1 2 31 end_hour end hour of the wind profile Options 0 6 12 or 18 Path to directory of NCEP files This will indicate the pathway to the directory where the NCEP input data is stored This directory should contain the fol
34. ricity minimum sphericity maximum Source Gaussian modal or Bi Gaussian bi modal grainsize distributions can be modelled FALL3D will generate Calculated average grainsize Number of particle classes python Options GAUSSIAN or BIGAUSSIAN Default 10 Units phi calculated degree of sorting of volcanic ash particles Calculated minimum grainsize Calculated maximum grainsize Analytically determined density minimum Analytically determined density maximum Analytically determined sphericity minimum how rounded are the volcanic ash particles Analytically determined sphericity maximum Units phi Units phi Units kg m3 Units kg m3 Value between 0 and 1 Value between 0 and 1 The source section is where the user defines the eruption style and magnitude mildly explosive highly explosive by specifying the column height and or the mass eruption rate Carey and Sparks 1986 Legros 2000 Pyle 1989 Sulpizio 2005 FALL3D uses one of three source models for eruption generation the possibilities are point suzuki or plume Appendix 6 The user is required to input different parameters depending on the source model chosen see below vent_height source type mass eruption rate height above vent A Height of the vent above sea level Models for eruption generation The rate at which magma is ejected from the vent eruption intensity
35. ruption given as the Default O number of hours since time O hours eruption duration Duration of the eruption given as a number of hours post eruptive settling duration Duration of post eruption ash settling given as a number of hours Location Volcanological input file The topography of the volcano and surrounding area are automatically read into python FALL3D and the user is only required to define the vent location within that topography in UTM coordinates x coordinate of vent x coordinate UTM of the vent location e g 439423 UTM zone implied by topography file y coordinate of vent y coordinate UTM of the vent location e g 9167213 UTM zone implied by topography file Vertical discretisation of the model domain The topography is used to define the horizontal extent of the modelled area in the x and y directions Vertical discretisation determines the vertical extent of the area being modelling in the z direction In combination they define the 3 dimensional space into which an eruption column is generated z min Minimum altitude of vertical domain Units m z max Maximum altitude of vertical domain Units m must be greater than the eruption column height z increment Division of vertical domain into layers Units m for volcanic ash to disperse usually 1 10 the z max i e z_max 10 000 then z increment 1000 Meteorological input There are three possible wind profile types 1 NCEP merged 2 NCEP m
36. sh modelling ALCA oooocnncccncccunanacanaananonananonoron nono nono nono nono nono non nn nro non non nnnnnnnos 9 5 2 Template SCHpIS ode cada dede doble undo raciones 9 d Prepatitse Input Dalai ueetenecsteeteteitet tees tula A ote ott LUE 11 7 Pr parine digital elev abou Cala ast rta ll b ot d td ie iata ut dee 11 72 Pre pario ineleorolopical d3ta3 so oett tette e Se escas 11 To Input variables tor python SCEIDIS 5i dh ton n d ton d tdi 11 8 Modelling Procedur ast onsectetuer G etu GpbtecG etus upto Geta unie ome ene on miM e I 18 S I Scenartosbased DEOCCUUPO iria accio 18 8 2 Hazard APPO esce ead ua aide teta aude A cci dolce Setia olt sabado ius ot Dee tr 20 O O E 22 PLCKMOW IEA ie ts ocio 25 IRETETON CES NAP pM IE NM 25 Appendix 1 Template for preparing digital elevation data oooooccccnnnnnnnnnnnnnnnnnnnnnnnnnononananinonoss 27 Appendix 2 Preparine meteorological data ere ERE i 28 Appendix 3 Volcanological input Worksheet coocccccccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnoss 29 Appendix 4 ane tab lao tds 31 Appendix 5 Running in parallel multiple nOdeS occccccccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnononininonos 32 Appendix 6 Glossary of volcanological and meteorological terMs ooococcccnnnnnnonnnnnnnnnnnnnnninonoss 33 111 Python FALL3D User Manual 1 Introduction 1 1 PURPOSE The volcanic ash dispersion model FALL3D Version 6
37. te scripts will appear ready for use 10 Python FALL3D User Manual f Preparing Input Data 7 1 PREPARING DIGITAL ELEVATION DATA Python FALL3D requires a digital elevation model DEM and accompanying projection file Digital elevation models must be in ESRI ASCII format e Use the template in Appendix to format a digital elevation model and accompanying projection file compatible with python FALL3D 7 2 PREPARING METEOROLOGICAL DATA Python FALL3D requires a meteorological input Two freely available options are currently available to users e NCEP 1 reanalysis historical wind conditions 1948 to present and e ACCCES T forecasted wind conditions 72 hr To download NCEP 1 reanalysis data e Refer to download instructions in Appendix 2 internet connection required To use ACCESS T data e Refer to Table 2 for web link python FALL3D will download automatically internet connection required 7 3 INPUT VARIABLES FOR PYTHON SCRIPTS The three python scripts extract_windprofiles py volcano py and create_hazard map py are used individually or in combination depending on the modelling procedure chosen Tables 1 3 provide descriptions of the input variables required for each script Table 1 Description and input options where applicable for each input parameter in the python script extract_windprofiles py Input parameter Description Units input options examples Location in UTM coo
38. thon scientific sudo apt get install gfortran sudo apt get install python gdal sudo apt get install gdal bin sudo apt get install libnetcdf dev Python FALL3D User Manual 5 First time installation of python FALL3D 5 1 INSTALLING PYTHON FALL3D Instructions for installing python FALL3D onto your PC for use in a linux UNIX environment are detailed below e Green text highlights the UNIX commands that are used e Blue text indicates a pathway of directories to be taken and e Red text indicates single directories file names websites programs and usernames You will only need to follow this step once for initial setup purposes It details how to create a sandpit where python FALL3D will be installed and run The example below provides suggested names for newly created directories highlighted by the symbols lt and gt Do not type the symbols lt and gt 1 Open a new terminal double click on the display icon on the desktop 2 To create a sandpit type mkdir lt sandpit gt e g mkdir sandpit 3 To change directory into your sandpit type cd lt sandpit gt 4 To download python FALL3D type Svn co username anonymous http www aifdr org svn aim branches fall3d_v6 aim 5 When prompted for a password press Enter no password necessary 6 To change to the python FALL3D source code directory type cd aim source aim 7 To install python Fall3D type python install fall3d py 8 W
39. ultiple and 3 ACCESS T The meteorological input will indicate where the wind data is stored as either a single profile merged a directory of multiple profiles multiple or a website link for the download of online forecasts ACCESS T wind profile lt home gt lt username gt lt tephra gt lt merged gt lt merged profile gt single profile OR T home username tephra multiple a directory of multiple profiles OR ftp ftp newb bom gov au register sample access netcdf ACESS T pressure Terrain model The user must specify which topographic file to use DEM by providing the pathway to the file Python FALL3D will automatically read in the accompanying projection file topography prj In this way the user can utilise a collection of DEM s at varying spatial resolutions topography grid T home username tephra dems topography txt Python FALL3D User Manual Granulometry The grainsize data should be based on quantitative analysis of volcanic ash samples for the volcano being modelled or a suitable analogue Bonadonna and Houghton 2005 Carey and Sigurdsson 1982 The values below will be derived from sieve data and calculation of the Inman parameters for grainsize distribution and sorting of volcanic ash deposits grainsize distribution number of grainsize classes mean grainsize sorting minimum grainsize maximum grainsize density minimum density maximum sphe
Download Pdf Manuals
Related Search