summary

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.
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
2. Produces a knickzone shapefile.
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

download

• ArcGIS Toolbox (.tbx) with Help files (zip, 51 KB)
• tutorial (pdf, 1.6 MB)
• sample data
• sample DEM GeoTIFF (zip, 71 MB)
• Rd raster (result of Step 1) GeoTIFF (zip, 75 MB)

help

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)

references

• 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