r.ros(1)		      Grass User's Manual		      r.ros(1)



NNAAMMEE
       rr..rrooss  (for  wildfire  spread  simulation)  -  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.

       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..rrooss

       rr..rrooss hheellpp

       rr..rrooss [-vs] mmooddeell==name  [moisture_1h=name]  [moisture_10h=name]	[mois-
       ture_100h=name]	 mmooiissttuurree__lliivvee==name  [velocity=name]  [direction=name]
       [slope=name] [aspect=name] [elevation=name] oouuttppuutt==name



       DDEESSCCRRIIPPTTIIOONN

       _r_._r_o_s 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  Labora-
       tory,  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 cal-
       culated 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 pro-
       gram  r.spread.	More information on r.ros and r.spread can be found in
       Xu (1994).



FFllaaggss::
       -v Run verbosely, printing information about program progress to  stan-
       dard output.

       -s Calculate the maximum potential spotting distance.



PPaarraammeetteerrss::
       mmooddeell==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.

       mmooiissttuurree__11hh==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).

       mmooiissttuurree__1100hh==name Name of an existing raster map layer  in  the	user's
       current	mapset	search path containing the 10-hour (.25-1") fuel mois-
       ture (percentage content multiplied by 100).

       mmooiissttuurree__110000hh==name Name of an existing raster map layer in  the	user's
       current mapset search path containing the 100-hour (1-3") fuel moisture
       (percentage content multiplied by 100).

       mmooiissttuurree__lliivvee==name Name of an existing raster map layer in  the	user's
       current mapset search path containing live (herbaceous) fuel fuel mois-
       ture (percentage content multiplied by 100).

       vveelloocciittyy==name Name of an existing raster map layer in the  user's  cur-
       rent mapset search path containing wind velocities at half of the aver-
       age flame height (feet/minute).

       ddiirreeccttiioonn==name	 Name of an existing raster map layer  in  the	user's
       current	mapset	search	path containing wind direction, clockwise from
       north (degree).

       ssllooppee==name	 Name of an existing raster map layer  in  the	user's
       current mapset search path containing topographic slope (degree).

       aassppeecctt==name	  Name	of an existing raster map layer in  the user's
       current mapset search  path  containing	topographic  aspect,  counter-
       clockwise from east (GRASS convention) (degree).

       eelleevvaattiioonn==name	  Name	of  an existing raster map layer in the user's
       current mapset search path containing elevation (meters).

       oouuttppuutt==name	 Prefix of new raster map layers in the   user's  cur-
       rent mapset to contain

	      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).

       If 'my_ros' is given as the  output  name,   then  r.ros  automatically
       assigns 'my_ros.base', 'my_ros.max', 'my_ros.maxdir', and optionally,



OOPPTTIIOONNSS
       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-interac-
       tively  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]	[mois-
       ture_100h=name]	 moisture_live=name  [velocity=name]  [direction=name]
       [slope=name] [aspect=name] [elevation=name] output=name

       If  the	options   mmooiissttuurree__11hh==name,   mmooiissttuurree__1100hh==name,   and	 mmooiiss--
       ttuurree__110000hh==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 vveelloocciittyy==name and
       ddiirreeccttiioonn==name must be in pair, whether given or not. If none is given,
       the program will assume a no-wind  condition.  Options  ssllooppee==name  and
       aassppeecctt==name  must  be  in pair, whether given or not. If none is given,
       the program will assume a topographically flat condition. Option eelleevvaa--
       ttiioonn==name must be given if -s option is used.



EEXXAAMMPPLLEE
       Assume  we have inputs, the following generates ROSes and spotting dis-
       tances:

       r.ros   -vs   model=fire_model	 moisture_1h=1hour_moisture	 mois-
       ture_live=live_moisture	velocity=wind_speed	 direction=wind_direc-
       tion slope=slope aspect=aspect	elevation=elevation output=my_ros



NNOOTTEESS
       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.

       2. The inputs to r.ros should be in proper units.

       3. The output units for the base and maximum  ROSes  are  in  cm/minute
       rather  than  ft/minute, which is due to that a possible zero ft/minute
       base ROS value and a  positive  integer	ft/minute  maximum  ROS  would
       result in calculation failure in the r.spread program.

       4.  The	user  needs  to  provide only ONE output name even the program
       actually generates THREE or FOUR map layers.

       5. The rules for optional parameters must be followed.



SSEEEE AALLSSOO
	_r_._m_a_s_k_, _r_._s_p_r_e_a_d





RREEFFEERREENNCCEESS
       AAllbbiinnii,, 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.

       AAnnddrreewwss, P. L., 1986, BEHAVE: fire behavior prediction and fuel	model-
       ing  system  -- BURN subsystem, Part 1, USDA Forest Service, Intermoun-
       tain Research Station, Gen. Tech. Rep. INT-194, Ogden, Utah.

       CChhaassee, Carolyn, H., 1984, Spotting distance  from  wind-driven  surface
       fires -- extensions of equations for pocket calculators, US Forest Ser-
       vice, Res. Note INT-346, Ogden, Utah.

       LLaatthhrroopp, Richard G. and Jianping Xu, A geographic  information  system-
       based approach for calculating spotting distance. (in preparation)

       RRootthheerrmmeell, R. E., 1972, A mathematical model for predicting fire spread
       in wildland fuels, USDA Forest Service, Intermountain Forest and  Range
       Experiment Station, Res. Pap. INT-115, Ogden, Utah.

       RRootthheerrmmeell,  Richard,  1991, Predicting behavior and size of crown fires
       in the northern Rocky Mountains, US Forest Service, Res. Paper INT-438,
       Ogden, Utah.

       XXuu,  Jianping,  1994,  Simulating  the spread of wildfires using a geo-
       graphic information system and remote  sensing,	Ph.  D.  Dissertation,
       Rutgers University, New Brunswick, New Jersey.



AAUUTTHHOORR
       Jianping  Xu,  Center  for Remote Sensing and Spatial Analysis, Rutgers
       University.



NNOOTTIICCEE
       This program is part of the alpha section of  the  GRASS  distribution.
       Unlike  the  code  in the main section of GRASS, the alpha code has not
       yet been fully tested for one release cycle.

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_4 _$



GRASS 5.0							      r.ros(1)
