Slope Units Delineation

Details: The software r.slopeunits requires a DEM, an optional raster layer showing alluvial plains, and the following user-defined parameters:

• the initial flow accumulation area threshold (t in square meters);

• the reduction factor r (integer, >1), that is used to calculate, iteratively, new values for the flow accumulation area threshold (t = t-t/r). Values larger than 5 are recommended;

• the minimum surface area for the slope units (a in square meters);

• the minimum circular variance of terrain aspect within a slope units (c, varies between 0 and 1, where 0 means no variance, i.e. cells dip in the same direction, and 1 means maximum variance);

• the maximum surface area for the slope units (maxarea, in square meters, optional);

• threshold area value for the cleaning procedures (cleansize, in square meters, used to remove very small slope units that may occur give some geomorphological conditions).

Details:

• Download for GRASS 6.4 slu_grass64.tgz
• Download for GRASS 7.0 slu_grass70.tgz
• Download for GRASS 7.8 slu_grass78.tgz
  
• Download for GRASS 8.4 and newer slu_grass84.zip
  
• Download for Windows users rslopeunits_win_grass84.zip
  

Italy: national map

1. su_italia
2. su_italia_lowres

Italy: landslide susceptibility maps

1. su_susc_italia
2. su_susc_italia_lowres

Italy: rockfall hazard

1. su_rockfall_hazard_lowres

Himalaya (mostly Nepal)

1. su_himalaya

Benchmark dataset and workflow

1. Input data (GPKG)
2. Input data (SHP)
3. Results presence 1 (GPKG)
4. Results presence 1 (SHP)
5. Results presence 2 (GPKG)
6. Results presence 2 (SHP)
7. Code

Details:

The software have been tested starting on Ubuntu 14.04 LTS server but        
should run on a generic GNU/Linux machine.                
	
	Requirements: our software require GRASS GIS 7.*, Python, Bash.                
	
	The two files contained in the tar.gz archives (one python script, one bash script) must be copied        
	in the “scripts” folder of the GRASS GIS installation directory. They must be executable (see below).        
	A typical approach, for the installation, is (replace grass78 for previous versions):               

	# open a bash shell               

	# change working directory to the download folder, e.g.:                

	cd /home/$USER/Downloads                

	# move the files into the scripts folder of the grass installation, e.g.:         

	mv r.slopeunits /usr/lib/grass78/scripts          

	mv clean_method_3.sh /usr/lib/grass78/scripts               

	# give execution rights                

	chmod ugo+x /usr/lib/grass78/scripts/r.slopeunits               

	chmod ugo+x /usr/lib/grass78/scripts/clean_method_3.sh                

	# run GRASS GIS in the location containing the digital elevation model type and:               

	r.slopeunits --help                

	# to see the options. The minimal command line to obtain a slope units delineation is                

	r.slopeunits demmap=[dem] slumap=[output_SU_map] thresh=[t, square meters] circularvariance=[c] areamin=[a, square meters] reductionfactor=[r, r>2] maxiteration=[max number of iterations]                

	# see: M. Alvioli, I. Marchesini, P. Reichenbach, M. Rossi, F. Fiorucci, F. Ardizzone, F. Guzzetti (https://doi.org/10.5194/gmd-9-3975-2016)         
	# and: M. Alvioli, F. Guzzetti, I.Marchesini (https://doi.org/10.1016/j.geomorph.2020.107124)        
	# and references therein for explanations, examples and additional options.        
	#        
	# please address comments, questions and bug fixes rquests either to:         
	# ivan.marchesini[AT]irpi.cnr.it;       
	# massimiliano.alvioli[AT]irpi.cnr.it       
	#