A real study · end to end
From a point cloud to a watershed
One bare-earth DTM → a full hydrologic stack, in plain lines:
each "*.las" | dtm resolution=1 | save "dtm/{name}.tif"
run gdal:merge INPUT="dtm/*.tif" OUTPUT=dtm.tif
run grass:r.watershed elevation=dtm.tif accumulation=accum.tif drainage=dir.tif basin=basin.tif
run grass:r.to.vect input=basin.tif type=2 output=catchments.gpkg
run saga:ta_channels:5 DEM=dtm.tif ORDER=strahler.tif SEGMENTS=streams.gpkg BASINS=basins.gpkg
Flow direction · flow accumulation · vector catchments · Strahler-ordered streams — GRASS & SAGA, one grammar.