The SCALGO Topoloy software package contains a number of modules for analysing and simplifying the topology of massive raster terrain models.
The package supports most common raster terrain data formats, including geotiff-, img-, bil- and asc-files. Furthermore, large datasets that are broken up into a mosaic of many smaller tiles can also be read and written effortlessly. The software package consists of the following modules, which can be run from a standalone graphical user interface or from a toolbox within ArcGIS.
Maps all depressions of a terrain model. The module identifies all cells of a raster model that are in a depression, and computes for each such cell the volume, depth or area of the depression below the cell.
Analyses the topology of a terrain model. The module identifies all depressions of a raster terrain model, including depressions inside other depressions, along with their nesting. This information can then be used by the Depression Filling module to remove "insignificant" depressions. The module can also output statistical information about the depressions, that is, the volume, depth or area of each depression.
Simplifies a terrain model. Given a raster terrain model and its topology (computed with the Depression Identification module), the module simplifies the model by filling ("insignificant") depressions based on their depth, area or volume (even depressions inside depressions) in a fully-specified way.
Identifies all flat areas of a terrain model. Given a rater terrain model, the module identifies all flat area raster cells, that is, all cells that are part of an area of cells with the same height and no downslope neighbor. The module also computes the size of each flat area in the model.