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r.ros(1grass) | Grass User's Manual | r.ros(1grass) |
NAME¶
r.ros - Generates three, or four raster map layers showing 1) the base (perpendicular) rate of spread (ROS), 2) the maximum (forward) ROS, 3) the direction of the maximum ROS, and optionally 4) the maximum potential spotting distance.KEYWORDS¶
raster, fireSYNOPSIS¶
r.rosFlags:¶
- -v
-
- -s
-
- --overwrite
-
- --verbose
-
- --quiet
-
Parameters:¶
- model=string
-
- moisture_1h=string
-
- moisture_10h=string
-
- moisture_100h=string
-
- moisture_live=string
-
- velocity=string
-
- direction=string
-
- slope=string
-
- aspect=string
-
- elevation=string
-
- output=string
-
DESCRIPTION¶
r.ros generates the base ROS value, maximum ROS value, direction of the maximum ROS, and optionally the maximum potential spotting distance of a wildfire for each raster cell in the current geographic region. The calculation of the two ROS values for each raster cell is based on the Fortran code by Pat Andrews (1983) of the Northern Forest Fire Laboratory, USDA Forest Service. The direction of the maximum ROS results from the vector addition of the forward ROS in wind direction and that in upslope direction. The spotting distance, if required, will be calculated by a separate function, spot_dist(), which is based on Lathrop and Xu (in preparation), Chase (1984) and Rothermel (1991). These three or four raster map layers serve as inputs for another GRASS raster program r.spread. More information on r.ros and r.spread can be found in Xu (1994).Parameters:¶
- model=name
-
Name of an existing raster map layer in the user's current mapset search path containing the standard fuel models defined by the USDA Forest Service. Valid values are 1-13; other numbers are recognized as barriers by r.ros.
- moisture_1h=name
-
Name of an existing raster map layer in the user's current mapset search path containing the 1-hour (<.25") fuel moisture (percentage content multiplied by 100).
- moisture_10h=name
-
- moisture_100h=name
-
- moisture_live=name
-
- velocity=name
-
- direction=name
-
- slope=name
-
- aspect=name
-
- elevation=name
-
- output=name
-
1) the base (perpendicular) ROS (cm/minute);
2) the maximum (forward) ROS (cm/minute),
3) the direction of the maximum ROS, clockwise from north (degree), and optionally
4) the maximum potential spotting distance (meters).
OPTIONS¶
r.ros can be run either non-interactively or interactively. The program is run interactively if the user types r.ros without specifying flag settings and parameter values on the command line. In this case, the user will be prompted for input. The program will be run non-interactively if the user specifies the names of raster map layers and any desired options on the command line, using the form:r.ros [-vs] model=name [moisture_1h=name] [moisture_10h=name] [moisture_100h=name] moisture_live=name [velocity=name] [direction=name] [slope=name] [aspect=name] [elevation=name] output=name If the options moisture_1h=name, moisture_10h=name, and moisture_100h=name are partially given, the program will assign values to the missing option using the formula: moisture_100h = moisture_10h + 1 = moisture_1h + 2. However at least one of them should be given. Options velocity=name and direction=name must be in pair, whether given or not. If none is given, the program will assume a no-wind condition. Options slope=name and aspect=name must be in pair, whether given or not. If none is given, the program will assume a topographically flat condition. Option elevation=name must be given if -s option is used.
EXAMPLE¶
Assume we have inputs, the following generates ROSes and spotting distances: r.ros -vs model=fire_model moisture_1h=1hour_moisture moisture_live=live_moisture velocity=wind_speed direction=wind_direction slope=slope aspect=aspect elevation=elevation output=my_rosNOTES¶
1. r.ros is supposed to be run before running another GRASS program r.spread. The combination of the two forms a simulation of the spread of wildfires.SEE ALSO¶
g.region, r.slope.aspect, r.spreadREFERENCES¶
Albini, F. A., 1976, Computer-based models of wildland fire behavior: a user's manual, USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, Utah.AUTHOR¶
Jianping Xu, Center for Remote Sensing and Spatial Analysis, Rutgers University. Last changed: $Date: 2009-05-23 10:12:36 +0200 (Sat, 23 May 2009) $ Full index © 2003-2014 GRASS Development TeamGRASS 6.4.4 |