[GRASS-dev] [GRASS GIS] #2981: r.watershed & blocking

[GRASS GIS]

#2981: r.watershed & blocking
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 Reporter:  mankoff  |      Owner:  grass-dev@…
     Type:  defect   |     Status:  new
 Priority:  normal   |  Milestone:  7.0.4
Component:  Raster   |    Version:  7.0.1
 Keywords:           |        CPU:  OSX/Intel
 Platform:  MacOSX   |
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 I'm not sure if this is a bug, but I think so. When I set the
 {{{blocking}} option to {{{r.watershed}}}, I see no difference in the
 accumulation map.

 The example below, which should work on the NC data set, creates a
 "blockage" at 30 m, runs {{{r.watershed}}} with and without the blockage,
 and compares results.

 {{{
 r.contour input=elev_srtm_30m at PERMANENT output=z_30_v levels=30
 v.to.rast --overwrite --verbose input=z_30_v type=line output=z_30_r use=z
 --overwrite
 r.mapcalc "rain = 1"
 r.watershed -s -a --v elevation=elev_srtm_30m accumulation=acc
 drainage=fdir  flow=rain
 r.watershed -s -a --v elevation=elev_srtm_30m accumulation=acc.block
 drainage=fdir.block flow=rain blocking=z_30_r
 g.gui.mapswipe first=acc second=acc.block
 }}}

 Also discussed at https://www.mail-archive.com/grass-
 user at lists.osgeo.org/msg31665.html and
 https://gis.stackexchange.com/questions/187310/what-does-the-blocking-
 option-do-in-grass-r-watershed

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2981>
GRASS GIS <https://grass.osgeo.org>