r.avaflow 2.3 Software
by Martin Mergili and Shiva P. Pudasaini
Be aware that the application of computer models in the field of natural hazards is highly critical. First, all tools, data and manuals were prepared with utmost care and with the purpose to be useful - however, they may still contain errors of various types. Second, even the best models only produce a distorted and generalized view of reality. Their interpretation requires (i) extreme care, (ii) a detailed understanding of the model and (iii) complementary information such as measurements or observations. The unreflected communication of model results may lead to unwanted consequences. Whilst the authors highly appreciate critics or suggestions, they clearly refuse any responsibility for any adverse consequences emanating from the use of any of the versions of the tool provided below.
The latest version of the r.avaflow 2.3 source code, including an installation script. Detailed instructions for the installation and operation of the tool are provided in the user manual. Training data are available for landslide-reservoir interactions in a computer-generated topography and for the Acheron Rock Avalanche in New Zealand.
Python-based GRASS GIS 7 module for filling depressions in the terrain with water. The installation procedure is the same as for r.avaflow. The following parameters are required to run r.lakefill:
- cellsize: raster cell size for computation. Please apply the same cellsize as for r.avaflow simulations using the output. Otherwise, the lake surface might not be perfectly plane, which would result in numerical oscillations.
- elevation: name of input GRASS raster map representing the terrain surface (usually in metres asl).
- lakedepth: name of output GRASS raster map of the computed lake depth (usually in metres). In r.avaflow, this raster can be used as the fluid release height (parameter hrelease3).
- level: lake level (usually in metres asl). Note that the lake level has to be lower than or equal to the lowest point surrounding the depression to be filled in order to achieve the desired result.
- seedcoords: Two comma-separated values describing the x and y coordinates (usually in metres) of an arbirary location within the depression to be filled. The point defined by these coordinates will be used as seed for filling the depression.
The module is executed through te terminal by calling its name along with the parameters. A possible example:
r.lakefill cellsize=5 elevation=test_elev lakedepth=test_lakedepth level=4256 seedcoords=483370,5120580
This script assists in visualizing the dimension of time in the results of r.avaflow 2.3 in Windows environments with ArcGIS. Essentially, a polygon shapefile is produced where each individual polygon shows the time after wich the corresponding area is reached by the mass flow under investigation. A certain understanding of ArcGIS, Python scripting, and the execution of Python scripts is required as well as an ArcGIS license (10.5 or higher) including the Spatial Analyst. A cmd script for starting the timestepper and an ArcMap 10.5 project file providing an example of how to visualize the outcomes can be downloaded along with the training data for the Acheron Rock Avalanche. The result of an application of the timestepper is shown in Mergili et al., 2018b.
The superprofiler helps to illustrate vertical longitudinal profiles of the frontal velocities of r.avaflow 2.3 mass flow simulations in Windows environments with ArcGIS. Polygon shapefiles are generated where the frontal velocity is shown for each individual time step of the simulation. This script depends on the outcome of the timestepper. A certain understanding of ArcGIS, Python scripting, and the execution of Python scripts is required as well as an ArcGIS license (10.5 or higher) including the Spatial Analyst and the 3D Analyst. A cmd script for starting the superprofiler and an ArcMap 10.5 project file providing an example of how to visualize the outcomes can be downloaded along with the training data for the Acheron Rock Avalanche. The result of an application of the superprofiler is shown in Mergili et al., 2018b.
The animator automatically creates input files necessary to generate 3D animations of r.avaflow 2.3 results in Windows environments with ArcGIS Pro. A certain understanding of ArcGIS Pro, Python scripting, and the execution of Python scripts is required as well as an ArcGIS Pro license. Note that the animator may fail for very large data sets in terms of raster cells and number of time steps. In such cases, subsets of time steps have to be processed individually. A cmd script for starting the animator and an ArcGIS Pro project file providing an example for an animation can be downloaded along with the training data for the landslide-reservoir interactions.
