r.spreadpathgrass - Online in the Cloud

PROGRAM:

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).

Use r.spreadpathgrass online using onworks.net services