This tool was created to identify knickzones (relatively steep segment along rivers) using a DEM by user specified constraints. It also calculates the height and length of the kniczones. The toold is designed for Esri ArcGIS software, comprising two steps as below:

  1. Computation of relative steepness (Rd) raster for a given DEM.
  2. Required:
    • Spatial Analyst license
    • TauDEM (5.1.1 for ArcGIS 10, 10.1, and 10.2)
    • DEM as GeoTIFF format
    • 'From', 'to', and 'by' values in scale for slope calculation
  3. Produces a knickzone shapefile.
  4. Required:
    • DEM as TIFF
    • Rd (relative steepness) raster previously calculated
    • Flow accumulation raster for stream network extraction
    • A threshold value in Rd for knickzone extraction



  1. tool part I
    computation of Rd raster by various scale slope calculation
  2. tool part II
    extraction of knickzones by Rd raster and knickzone form calculation

source code

  1. tool part I (txt)
  2. tool part II (txt)


  • Hayakawa, Y.S., Oguchi, T., 2006: DEM-based identification of fluvial knickzones and its application to Japanese mountain rivers. Geomorphology 78, 90–106. doi:10.1016/j.geomorph.2006.01.018
  • Hayakawa, Y.S., Oguchi, T., 2009: GIS analysis of fluvial knickzone distribution in Japanese mountain watersheds. Geomorphology 111, 27–37. doi:10.1016/j.geomorph.2007.11.016
  • Zahra, T., Paudel, U., Hayakawa, Y.S., Oguchi, T. (2017.04) Knickzone Extraction Tool (KET) - A new ArcGIS toolset for automatic extraction of knickzones from a DEM based on multi-scale stream gradients. Open Geosciences, 9 (1), 73-88. doi:10.1515/geo-2017-0006