1r.spreadpath(1) GRASS GIS User's Manual r.spreadpath(1)
2
6 r.spreadpath - Recursively traces the least cost path backwards to
7 cells from which the cumulative cost was determined.
8
10 raster, fire, cumulative costs
11
13 r.spreadpath
14 r.spreadpath --help
15 r.spreadpath x_input=name y_input=name [coordi‐
16 nates=east,north[,east,north,...]] output=name [--overwrite]
17 [--help] [--verbose] [--quiet] [--ui]
18 Flags:
20 --overwrite
21 Allow output files to overwrite existing files
22 --help
24 Print usage summary
25 --verbose
27 Verbose module output
28 --quiet
30 Quiet module output
31 --ui
33 Force launching GUI dialog
34 Parameters:
36 x_input=name [required]
37 Name of raster map containing back-path easting information
38 y_input=name [required]
40 Name of raster map containing back-path northing information
41 coordinates=east,north[,east,north,...]
43 The map E and N grid coordinates of starting points
44 output=name [required]
46 Name for output raster map
47
49 r.spreadpath is part of the wildfire simulation toolset. Preparational
50 steps for the fire simulation are the calculation of the rate of spread
51 (ROS) with r.ros, and the creating of spread map with r.spread. Even‐
52 tually, the fire path(s) based on starting point(s) are calculated with
53 r.spreadpath.
54 r.spreadpath recursively traces the least cost path backwards to the
56 origin, given backlink information input map layers and target loca‐
57 tions from where paths are to be traced. The backlink information map
58 layers record each cell’s backlink UTM northing (the y_input) and east‐
59 ing (the x_input) coordinates from which the cell’s cumulative cost was
60 determined.
61 The backlink inputs can be generated from another GRASS raster program
63 r.spread. One of the major applications of r.spreadpath along with
64 r.spread is to accurately find the least cost corridors and/or paths on
65 a raster setting. More information on r.spread and r.spreadpath can be
66 found in Xu (1994).
67
69 x_input=name
70 Name of input raster map layer containing backlink UTM easting co‐
71 ordinates.
72 y_input=name
74 Name of input raster map layer containing backlink UTM northing co‐
75 ordinates.
76 coordinates =x,y[,x,y,x,y, ...]
78 Each x,y coordinate pair gives the easting and northing (respec‐
79 tively) geographic coordinates of a target point from which to
80 backwards trace the least cost path. As many points as desired can
81 be entered by the user.
82 output=name
84 Name of raster map layer to contain output. Also can be used as the
85 map layer of the input target points. If so used, the input target
86 point map will be overwritten by the output.
87
89 • Xu, Jianping, 1994, Simulating the spread of wildfires using a
90 geographic information system and remote sensing, Ph. D. Dis‐
91 sertation, Rutgers University, New Brunswick, New Jersey (ref).
92
94 r.spread, r.ros Sample data download: firedemo.sh (run this script
95 within the "Fire simulation data set" location.
96
98 Jianping Xu and Richard G. Lathrop, Jr., Center for Remote Sensing and
99 Spatial Analysis, Rutgers University.
100
102 Available at: r.spreadpath source code (history)
103 Accessed: Mon Jun 20 16:46:27 2022
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108 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
110GRASS 8.2.0 r.spreadpath(1)