Workspaces – Importing terrain data

SCALGO Live supports importing certain kinds of terrain data into workspaces. You can choose to create a new workspace based on such data, or incorporate the data into an existing workspace. Using an existing workspace is recommended in many cases, since it allows you to place the imported data in the context of a base model.

Do the following to incorporate locally stored terrain data into an existing workspace:

1. Open the workspace dialog using the button
   
2. Click Import terrain model ....
   
3. Click choose files to select the relevant file(s) (hold down Ctrl in the file-selector dialog to select multiple files). It is also possible to use a ZIP file containing relevant data. See below for a list of supported file formats.

Alternatively, you can create a new workspace based on your locally stored terrain data by uploading the file(s) through the workspace creation tool.

Imported data should be georeferenced and have a spatial reference with a known EPSG code. If the spatial reference is not automatically detected, you can look up the EPSG code for your spatial reference system at for example epsg.io or spatialreference.org. Elevation values are always assumed to be in meters. See the manual entry on Coordinate Systems for more information.

Extending and replacing elevation data

When importing terrain data partially overlapping existing data in a workspace, the workspace will be extended using the new data. For the part overlapping existing data, you can choose if the old or new data should be used by selecting the appropriate option in the "Merge order" submenu.

By first downloading data for e.g. a national elevation model, you can effectively extend your existing workspace, or revert previous imports that should be undone.

Raster data formats

The following raster terrain formats are supported:

• GeoTIFF (.tif)
• BIL/.hdr Labelled Raster (.bil + .hdr)
• HFA/Erdas Imagine (.img)
• Arc/Info ASCII Grid (.asc + .prj)
• Arc/Info Binary Grid (.adf, multiple files)
• USGS DEM (.dem)
• ASCII Gridded XYZ (.xyz)
• DFS2 (.dfs2): elevation data; other data can be visualized through modelspaces.

If not embedded, spatial references are also read from .aux.xml PAM files if provided.
When uploading multiple raster files, make sure they are using the same spatial reference and resolution (pixel sizes).

Note that nodata values in the raster are considered to be sea(-like) areas. When running sea-level rise analysis, these areas will be used as source of flooding, and when running flow analysis, these areas will consume any adjacent flow. When no nodata values exist, sea-level rise will consider the lowest cell as the flood source.

TIN (triangle) data formats

We support generating a workspace elevation model based on triangulated meshes. These can be exported from BIM/CAD software (such as Trimble Novapoint, AutoCAD Civil 3D and Bentley InRoads/PowerCivil). When importing a triangulated mesh, we find the highest (or lowest) point at each raster cell center and use this elevation in the workspace. The following TIN formats are supported:

• LandXML (.xml)
  Note that only TIN data (LandXML Surfaces) in the file will be imported.
• Shapefile (.shp + .shx + .prj)
  Triangles should be represented as polygon features with 3D coordinates.
  

Point cloud formats

When importing a point cloud, we first create a Delaunay triangulation (TIN) of the point cloud, and then, rasterize the triangulation as described above. The following point cloud formats are supported:

• LAS (.las, .laz)
  If the point cloud is classified only points with class 2 ("ground") are used.
  
• Shapefile (.shp + .shx + .dbf + .prj)
  Using 3D point features or 2D point features with elevation stored in the first attribute.
• XYZ (.xyz, .txt)
  ASCII text files with one point per line, coordinates separated by spaces (example).