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PolyGeo
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GRASS GIS - Using r.water.outlet - What is my mistake?of GRASS GIS

I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation.

  • Downloaded SRTM-Geotiff file
  • Location, Mapset all o.k
  • Used r.in.gdal to import SRTM file
  • Filled the sinks using r.terraflow
  • Masked the filled raster
  • Zoomed the required region & set the computational region
  • Ran r.watershed using threshold=10000
  • Got drainge, basin, stream & visual rasters
  • Visual rendering of rasters (drainge, basin, stream & visual) - o.k
  • Different Watersheds (basins) displayed for entire area
  • Zoomed stream raster to find lat/lon of mouth of river (cross checked with Google earth)
  • Converted the lat/lon as decimal
  • Ran r.water.outlet using stream as input & gave the lat/lon as easting & northing
  • Sadly the output display is blank
  • Rerun r.water.outlet - only a small dot in the lat/lon point. No delineation of watershed for the given easting & northing
  • All the above procedures as per manuals
  • Self learning of GRASS GIS - no formal training

Since I'm new here, I'm not permitted to upload the result images - Sorry...

What is the mistake I'm doing? How todo I get the watershed (basin) for the given lat/lon? Kindly help. Thanks in advance...

GRASS GIS - r.water.outlet - What is my mistake?

I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation.

  • Downloaded SRTM-Geotiff file
  • Location, Mapset all o.k
  • Used r.in.gdal to import SRTM file
  • Filled the sinks using r.terraflow
  • Masked the filled raster
  • Zoomed the required region & set the computational region
  • Ran r.watershed using threshold=10000
  • Got drainge, basin, stream & visual rasters
  • Visual rendering of rasters (drainge, basin, stream & visual) - o.k
  • Different Watersheds (basins) displayed for entire area
  • Zoomed stream raster to find lat/lon of mouth of river (cross checked with Google earth)
  • Converted the lat/lon as decimal
  • Ran r.water.outlet using stream as input & gave the lat/lon as easting & northing
  • Sadly the output display is blank
  • Rerun r.water.outlet - only a small dot in the lat/lon point. No delineation of watershed for the given easting & northing
  • All the above procedures as per manuals
  • Self learning of GRASS GIS - no formal training

Since I'm new here, I'm not permitted to upload the result images - Sorry...

What is the mistake I'm doing? How to get the watershed (basin) for the given lat/lon? Kindly help. Thanks in advance...

Using r.water.outlet of GRASS GIS

I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation.

  • Downloaded SRTM-Geotiff file
  • Location, Mapset all o.k
  • Used r.in.gdal to import SRTM file
  • Filled the sinks using r.terraflow
  • Masked the filled raster
  • Zoomed the required region & set the computational region
  • Ran r.watershed using threshold=10000
  • Got drainge, basin, stream & visual rasters
  • Visual rendering of rasters (drainge, basin, stream & visual) - o.k
  • Different Watersheds (basins) displayed for entire area
  • Zoomed stream raster to find lat/lon of mouth of river (cross checked with Google earth)
  • Converted the lat/lon as decimal
  • Ran r.water.outlet using stream as input & gave the lat/lon as easting & northing
  • Sadly the output display is blank
  • Rerun r.water.outlet - only a small dot in the lat/lon point. No delineation of watershed for the given easting & northing
  • All the above procedures as per manuals
  • Self learning of GRASS GIS - no formal training

How do I get the watershed (basin) for the given lat/lon?

Tweeted twitter.com/#!/StackGIS/status/249886115803312128
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Vishy
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GRASS GIS - r.water.outlet - What is my mistake?

I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation.

  • Downloaded SRTM-Geotiff file
  • Location, Mapset all o.k
  • Used r.in.gdal to import SRTM file
  • Filled the sinks using r.terraflow
  • Masked the filled raster
  • Zoomed the required region & set the computational region
  • Ran r.watershed using threshold=10000
  • Got drainge, basin, stream & visual rasters
  • Visual rendering of rasters (drainge, basin, stream & visual) - o.k
  • Different Watersheds (basins) displayed for entire area
  • Zoomed stream raster to find lat/lon of mouth of river (cross checked with Google earth)
  • Converted the lat/lon as decimal
  • Ran r.water.outlet using stream as input & gave the lat/lon as easting & northing
  • Sadly the output display is blank
  • Rerun r.water.outlet - only a small dot in the lat/lon point. No delineation of watershed for the given easting & northing
  • All the above procedures as per manuals
  • Self learning of GRASS GIS - no formal training

Since I'm new here, I'm not permitted to upload the result images - Sorry...

What is the mistake I'm doing? How to get the watershed (basin) for the given lat/lon? Kindly help. Thanks in advance...