elevation = "dem_1m.tif"
outdir = substr(elevation, start = 1, stop = nchar(elevation)-4)
dir.create(outdir)
accumulation = paste0(outdir, "/accumulation.tif")
drainage = paste0(outdir, "/drainage.tif")
basin = paste0(outdir, "/basin.tif")
stream = paste0(outdir, "/stream.tif")
half_basin = paste0(outdir, "/half_basin.tif")
slope_length = paste0(outdir, "/slope_length.tif")
slope_steepness = paste0(outdir, "/slope_steepness.tif")
tci = paste0(outdir, "/twi.tif")
spi = paste0(outdir, "/spi.tif")
cmd = paste0("qgis_process run grass7:r.watershed",
" --distance_units=meters",
" --area_units=m2",
" --ellipsoid=EPSG:7019",
" --elevation=", elevation,
" --threshold=100 --convergence=5 --memory=300",
" ---s=false ---m=false ---4=false ---a=true ---b=false",
" --accumulation=", accumulation,
" --drainage=", drainage,
" --basin=", basin,
" --stream=", stream,
" --half_basin=", half_basin,
" --length_slope=", slope_length,
" --slope_steepness=", slope_steepness,
" --tci=", tci,
" --spi=", spi,
" --GRASS_REGION_CELLSIZE_PARAMETER=0 --GRASS_RASTER_FORMAT_OPT= --GRASS_RASTER_FORMAT_META=")
system(cmd)