Geomorphometry

GRASS in Geomorphometry

Import and computing of DEMs

• Grid-based DEMs in various formats can be imported using the r.in.gdal command
• Elevation data represented by digitised contours or measured points can be imported using the v.in.ogr command that supports numerous vector formats
• Data given as an ASCII list of (x, y, z) coordinates can be imported with v.in.ascii
• Very dense ASCII point data (e.g. from LiDAR), can be directly converted to raster using r.in.xyz by performing a binning procedure based on different statistical measures (min, max, mean, range, etc.).

Useful commands

• d.polar
• r.drain
• r.flow
• r.mapcalc
• r.slope.aspect
• ...

References

• Grohmann, C.H., 2004. Morphometric analysis in geographic information systems: applications of free software GRASS and R. Computers & Geosciences, 30(9-10), pp.1055-1067. http://dx.doi.org/10.1016/j.cageo.2004.08.002
• Grohmann, C.H., 2005. Trend-surfaces analysis of morphometric parameters: A case study in southeastern Brazil Computers & Geosciences, 31, 1005-1014. http://dx.doi.org/10.1016/j.cageo.2005.02.011
• Grohmann, C. H.; Riccomini, C. & Alves, F. M. , 2007. SRTM-based morphotectonic analysis of the Pocos de Caldas Alkaline Massif, southeastern Brazil Computers & Geosciences, 33, 10-19. http://dx.doi.org/10.1016/j.cageo.2006.05.002
• Grohmann, C. H. & Riccomini, C., 2009. Comparison of roving-window and search-window techniques for characterising landscape morphometry Computers & Geosciences, 35, 2164-2169. http://dx.doi.org/10.1016/j.cageo.2008.12.014
• Grohmann, C. H.; Smith, M. J. & Riccomini, C., 2010. Multiscale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland Geoscience and Remote Sensing, IEEE Transactions on, 49, 1200-1213. http://dx.doi.org/10.1109/TGRS.2010.2053546
• Grohmann, C. H.; Riccomini, C. & Chamani, M. A. C., 2011. Regional scale analysis of landform configuration with base-level (isobase) maps Hydrology and Earth System Sciences, 15, 1493-1504. http://dx.doi.org/10.5194/hess-15-1493-2011
• Hengl, T. & Reuter, H.I., 2009. Geomorphometry : concepts, software, applications, Amsterdam; Oxford: Elsevier.
• Hofierka, J., Mitasova, H. & Neteler, M., 2009. Geomorphometry in GRASS GIS. In Developments in Soil Science. Elsevier, pp. 387-410. Available at: http://dx.doi.org/10.1016/S0166-2481(08)00017-2.
• Le Coz, M. et al., 2009. Assessment of Digital Elevation Model (DEM) aggregation methods for hydrological modeling: Lake Chad basin, Africa. Computers & Geosciences, 35(8), pp.1661-1670.