/* script to calculate a bunch of landscape parameters with GRID
/* to be run in grid

&s zgrid = q2446

&type %zgrid%

&s cellsize = 10
setcell %cellsize%

&s maxcurv = 2

&if [exist slopeg -grid] &then kill slopeg all
slopeg = slope(%zgrid%, percentrise)

&if [exist fdir -grid] &then kill fdir all
&if [exist fillg -grid] &then kill fillg all
fill %zgrid% fillg sink # fdir

&if [exist facc -grid] &then kill facc all
facc = flowaccumulation(fdir)

&s critical_area = 1000000  
&s critical_cells = [calc %critical_area% / ( %cellsize% * %cellsize% ) ]

&if [exist channels -grid] &then kill channels all
channels = con(facc > %critical_cells%, 1, 0)

&if [exist curv -grid] &then kill curv all
curv = curvature(%zgrid%)

&if [exist airtemp -grid] &then kill airtemp all
airtemp = 28 - 0.01 * %zgrid%

&if [exist solarheat -grid] &then kill solarheat all
solarheat = hillshade(%zgrid%, 180, 45) * 25 / 255

&if [exist soiltemp -grid] &then kill soiltemp all
soiltemp = airtemp + solarheat


&if [exist goodg -grid] &then kill goodg all
goodg = con(soiltemp > 33 and soiltemp < 43 and channels == 0 and slopeg <= 20 and curv < %maxcurv%, 1, 0)


&return