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 (perpendicu-
       lar)  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]   [mois-
       ture_10h=name]	[moisture_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 Laboratory, USDA Forest Service. The direction of the
       maximum	ROS  results from the vector addition of the for-
       ward 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  Lath-
       rop  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).



FFllaaggss::
       -v  Run	verbosely,  printing  information  about  program
       progress to standard 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 stan-
       dard 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  multi-
       plied 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 moisture (percentage content multi-
       plied 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  multi-
       plied 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 moisture (percentage content multi-
       plied by 100).

       vveelloocciittyy==name Name of an existing raster map layer in  the
       user's  current mapset search path containing wind veloci-
       ties at half of the average 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 topo-
       graphic slope (degree).

       aassppeecctt==name	 Name of an existing raster map layer  in
       the  user's  current  mapset  search path containing topo-
       graphic aspect, counter-clockwise from east (GRASS conven-
       tion) (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 current 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 auto-
       matically     assigns	 'my_ros.base',     'my_ros.max',
       'my_ros.maxdir', and optionally,



OOPPTTIIOONNSS
       r.ros can be  run  either  non-interactively  or  interac-
       tively. The program is run interactively if the user types
       r.ros without specifying flag settings and parameter  val-
       ues  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 lay-
       ers 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]	    mois-
       ture_live=name	    [velocity=name]	 [direction=name]
       [slope=name] [aspect=name] [elevation=name] output=name

       If the options  mmooiissttuurree__11hh==name,  mmooiissttuurree__1100hh==name,  and
       mmooiissttuurree__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 eelleevvaattiioonn==name must be given if -s option is  used.



EEXXAAMMPPLLEE
       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    ele-
       vation=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 modeling system -- BURN subsystem, Part 1, USDA  For-
       est  Service,  Intermountain  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 Service, Res. Note INT-346,  Ogden,
       Utah.

       LLaatthhrroopp, Richard G. and Jianping Xu, A geographic informa-
       tion system-based approach for calculating  spotting  dis-
       tance. (in preparation)

       RRootthheerrmmeell,  R. E., 1972, A mathematical model for predict-
       ing 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 geographic information system and remote sensing,
       Ph. D. Dissertation, Rutgers  University,  New  Brunswick,
       New Jersey.



AAUUTTHHOORR
       Jianping  Xu, Center for Remote Sensing and Spatial Analy-
       sis, 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)
