PyGRASS

test_pygrass.py

import os
import sys

outdir = os.path.abspath(os.path.join(os.path.dirname(__file__), 'output'))
if not os.path.exists(outdir):
    os.mkdir(outdir)
input_elevation = "dem.img"

gisbase = os.environ['GISBASE'] = "/usr/local/grass-7.0.0svn"

# putting $GISBASE/lib (with $GISBASE replaced by its actual value) 
# into /etc/ld.so.conf then running ldconfig).
# os.environ['LD_LIBRARY_PATH'] = os.path.join(gisbase, 'lib')
# print os.environ['LD_LIBRARY_PATH']

gisdbase = os.path.join('.')

# TODO create these with correct projection info for the input raster(s)
location = "bigsur"
mapset   = "PERMANENT"

sys.path.append(os.path.join(os.environ['GISBASE'], "etc", "python"))

import grass.script.setup as gsetup
gsetup.init(gisbase, gisdbase, location, mapset)
###############################################################################

from grass.pygrass.modules.shortcuts import raster as rast
from grass.pygrass.modules.shortcuts import general


general.mremove(rast="*", f=True)

elev = "dem"
slope = "slope.img"
aspect = "aspect.img"

rast.external(input=input_elevation, output=elev, overwrite=True)
rast.external_out(directory=outdir, format="HFA")

rast.slope_aspect(elevation=elev, slope=slope, aspect=aspect, format='percent', overwrite=True)

rast.topidx(input=elev, output="topidx.img")

rast.sun (elev_in=elev, asp_in=aspect, slope_in=slope,
      lin=2.5, alb=0.2, day=172,
      #beam_rad=b172b diff_rad=d172b, refl_rad=r172b insol_time=it172b, glob_rad=g172b
      insol_time='insoltime_172.img', glob_rad='globalrad_172.img')

Resources:

• http://grasswiki.osgeo.org/wiki/Working_with_GRASS_without_starting_it_explicitly
• http://grasswiki.osgeo.org/wiki/Python/pygrass

Some other useful terrain commands in GRASS 7

r.external ?? 

r.in.gdal input=dem.img output=dem location=bigsur2

r.topidx input=dem output=topidx

r.sunmask --v dem output=sunmask_0427 year=2014 month=4 \
          day=27 hour=16 minute=30 sec=0 timezone=-8

r.sun -s dem lin=2.5 alb=0.2 day=172 \
      beam_rad=b172 diff_rad=d172 \
      refl_rad=r172 insol_time=it172 \
      glob_rad=g172

r.param.scale in=dem output=morphology size=9 param=feature 
r.param.scale in=dem output=minic size=9 param=minic
r.param.scale in=dem output=maxic size=9 param=maxic
r.param.scale in=dem output=crosc size=9 param=crosc
r.param.scale in=dem output=planc size=9 param=planc
r.param.scale in=dem output=profc size=9 param=profc
r.param.scale in=dem output=longc size=9 param=longc
r.param.scale in=dem output=slope size=9 param=slope
r.param.scale in=dem output=aspect size=9 param=aspect


r.mfilter.fp

r.slope.aspect   # compare to param.scale slope= aspect pcurv tcurv

r.flow # *out ... vector output

r.watershed

r.water.outlet

r.viewshed

r.uslek r.usler - USLE model params

r.topmodel

r.stream.extract

r.shaded.relief map=dem shadedmap=dem_shaded

r.terraflow elev=dem filled=dem_filled \
    dir=dem_dir swatershed=dem_watershed \
    accumulation=dem_accu tci=dem_tci memory=2500 \
    stats=terraflow_stats.txt 

r.sim.sediment  # Sediment transport and erosion/deposition simulation
r.sim.water  # Overland flow hydrologic simulation using path sampling method (SIMWE).
r.solute.transport  r.gwflow

r.basins.fill

r.drain

r.fill.dir