Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
NAME
v.stream.network - Build a linked stream network: each link knows its downstream linkKEYWORDS
vector, stream network, hydrology, geomorphologySYNOPSIS
v.stream.network
v.stream.network --helpv.stream.network map=name [upstream_easting_column=string] [upstream_northing_column=string] [downstream_easting_column=string] [downstream_northing_column=string] [tostream_cat_column=string] [--help] [--verbose] [--quiet] [--ui]
Flags:
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- map=name [required]
- Vector stream network from r.stream.extract
- Or data source for direct OGR access
- upstream_easting_column=string
- Upstream easting (or x or lon) column name
- Default: x1
- upstream_northing_column=string
- Upstream northing (or y or lat) column name
- Default: y1
- downstream_easting_column=string
- Downstream easting (or x or lon) column name
- Default: x2
- downstream_northing_column=string
- Downstream northing (or y or lat) column name
- Default: y2
- tostream_cat_column=string
- Adjacent downstream segment cat (0 = offmap flow)
- Default: tostream
Table of contents
DESCRIPTION
v.stream.network populates the attribute table of a river network built by r.stream.extract with five new columns that define the nodes and links within a river network. These are (default names given):- x1, y1: upstream coordinates
- x2, y2: downstream coordinates
- tostream: category number of the next stream; is equal to 0 if the stream flows off of the map
NOTES
streams is a set of vector lines that is generated by r.stream.extract. It is recommended to be built as follows (Python code):
# Choose elevation map and threshold
elevation = srtm
threshold = 1E6 # [m**2], minimum catchment size = 1 km**2
# Build a map of cell areas: pick one of these
# km2 is more intuitive, but 1 km2 is the threshold for the smallest
# threshold catchment size
r.mapcalc('cellArea_meters2 = '+str(reg.nsres)+' * '+str(reg.ewres), overwrite=True)
r.mapcalc("cellArea_km2 = cellArea_meters2 / 10^6", overwrite=True)
# Use r.watershed to build a drainage basin with units of length**2
# instead of arbitrary units (cells)
r.watershed(elevation=elevation, flow='cellArea_meters2', accumulation='drainageArea_m2', drainage='drainageDirection', stream='streams', threshold=thresh, flags='s', overwrite=True)
# Note that this will include areas of negative (i.e. offmap) flow accumulation
# Build watershed network using r.stream.extract: single-flow-direction (SFD)
print "Building drainage network"
r.stream_extract(elevation=elevation, accumulation='drainageArea_m2', threshold=thresh, d8cut=0, mexp=0, stream_raster='streams', stream_vector='streams', direction='draindir', overwrite=True)
SEE ALSO
r.stream.extract v.stream.orderREFERENCES
None (yet)AUTHOR
Andrew D. WickertSOURCE CODE
Available at: v.stream.network source code (history)
Latest change: Mon Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55
Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
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© 2003-2023 GRASS Development Team, GRASS GIS 7.8.8dev Reference Manual