xenial (1) r.spreadpath.1grass.gz

NAME

       r.spreadpath   - Recursively traces the least cost path backwards to cells from which the cumulative cost
       was determined.

KEYWORDS

       raster, fire, cumulative costs

SYNOPSIS

       r.spreadpath
       r.spreadpath --help
       r.spreadpath   x_input=name    y_input=name     [coordinates=east,north[,east,north,...]]     output=name
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       x_input=name [required]
           Name of raster map containing back-path easting information

       y_input=name [required]
           Name of raster map containing back-path northing information

       coordinates=east,north[,east,north,...]
           The map E and N grid coordinates of starting points

       output=name [required]
           Name for output raster map

DESCRIPTION

       r.spreadpath  is part of the wildfire simulation toolset. Preparational steps for the fire simulation are
       the calculation of the rate of spread (ROS) with r.ros, and the creating of  spread  map  with  r.spread.
       Eventually, the fire path(s) based on starting point(s) are calculated with r.spreadpath.

       r.spreadpath  recursively  traces the least cost path backwards to the origin, given backlink information
       input map layers and target locations from where paths are to be traced.  The  backlink  information  map
       layers  record each cell’s backlink UTM northing (the y_input) and easting (the x_input) coordinates from
       which the cell’s cumulative cost was determined.

       The backlink inputs can be generated from another  GRASS  raster  program  r.spread.  One  of  the  major
       applications  of  r.spreadpath  along with r.spread is to accurately find the least cost corridors and/or
       paths on a raster setting. More information on r.spread and r.spreadpath can be found in Xu (1994).

Parameters:

       x_input=name
           Name of input raster map layer containing backlink UTM easting coordinates.

       y_input=name
           Name of input raster map layer containing backlink UTM northing coordinates.

       coordinates =x,y[,x,y,x,y, ...]
           Each x,y coordinate pair gives the easting and northing (respectively) geographic  coordinates  of  a
           target  point  from  which  to  backwards trace the least cost path. As many points as desired can be
           entered by the user.

       output=name
           Name of raster map layer to contain output. Also can be used as the map layer  of  the  input  target
           points. If so used, the input target point map will be overwritten by the output.

REFERENCES

           •   Xu,  Jianping, 1994, Simulating the spread of wildfires using a geographic information system and
               remote sensing, Ph. D. Dissertation, Rutgers University, New Brunswick, New Jersey (ref).

SEE ALSO

        r.spread, r.ros Sample data download: firedemo.sh (run this script within the "Fire simulation data set"
       location.

AUTHOR

       Jianping  Xu  and  Richard  G.  Lathrop,  Jr.,  Center  for  Remote Sensing and Spatial Analysis, Rutgers
       University.

       Last changed: $Date: 2014-11-28 16:46:08 +0100 (Fri, 28 Nov 2014) $

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