Typical usage of digger.make¶
Many runout models, including D-Claw, require specification of the location and depth of initial, potentially mobile, material as one type of input file.
Rather than creating these input files by hand, digger makes it easier to create those files using standard raster and vector geospatial formats. digger.make provides methods to generate the three dimensional geometry of a landslide based on topographic information and the two dimensional planimetric extent of a landslide. digger also generates figures and geotif-format files to support the user in undertaking quality control of the files it generates. These figures are not intended as publication quality.
The expected usage of digger is in support of running simulations with D-Claw. digger streamlines creating input files in topotype3 format for D-Claw based on geotif format topography files and polygons depicting the extent of landslides provided as shapefiles. For a specific application, a user may use one or more of the functions provided in digger.make. For example, if one is interested in simulating entrainment by a landslide of initially constant thickness, one would use both make.slabs and make.entrainment
A user might ask: ‘For my application, which of the digger.make functions is right for me?’ The answer would depend on the specific application, the goals of the user, and how the user chooses to idealize the landslide. If the user thinks the geometry of the landslide failure surface is best represented as a logarithmic spiral, then make.scoops would be the most appropriate. Alternatively, if the landslide thickness is constant, then make.slabs would be most appropriate. If the user is interested in an application where some material may be entrained, they would likely want to use make.entrainment to generate these input files. If the user is interested in the behavior of material impounded in reservoirs behind hypothetical dams, then make.reservoir may be the most appropriate choice.
Finally, the method make.new_water may be of use if a user is doing work in an area where deglaciation has exposed new water or no bathymetry exists for a lake. This method can modify topobathymetry to add new water in areas with simple geometries.
We note that the functions provided in digger.make do not represent a formal analysis of slope stability. digger calculates the geometry of landslide material using idealized geometries (logarithmic spirals, constant depths). It is the obligation of the user to determine whether any of the idealized landslide geometries generated by digger.make are appropriate for their application, given their understanding of the geology, geomorphology, and geotechnical characteristics of the site.