Running r.stream.extract and removing nulls from the accumulation map
produces weighted and unweighted stream maps with no data:
r.info dem.noweight.streams
Title: ( dem.noweight.streams )
Type of Map: raster Number of Categories: 0
Data Type: CELL
Rows: 1045
Columns: 1457
Total Cells: 1522565
Projection: Transverse Mercator
N: 28660140.36123598 S: 28628801.89941604 Res: 29.98895868
E: 549219.21981511 W: 505505.97596796 Res: 30.00222639
Range of data: min = NULL max = NULL
Data Description:
generated by r.stream.extract
r.info dem.weighted.streams
Title: ( dem.weighted.streams )
Type of Map: raster Number of Categories: 0
Data Type: CELL
Rows: 1045
Columns: 1457
Total Cells: 1522565
Projection: Transverse Mercator
N: 28660140.36123598 S: 28628801.89941604 Res: 98895868
E: 549219.21981511 W: 505505.97596796 Res: 30.00222639
Range of data: min = NULL max = NULL
Data Description:
generated by r.stream.extract
Comments:
r.stream.extract elevation="dem_proj" accumulation="dem.weighted" th\
reshold=1000 d8cut=infinity mexp=0 stream_length=0 stream_rast="dem.\
weighted.streams"
What might I have done incorrectly now? Again, each step followed the
r.stream.extract example with the addition of running r.null on the
accumulation map.
Running r.stream.extract and removing nulls from the accumulation map
produces weighted and unweighted stream maps with no data:
there would have been a misunderstanding. Probably null values have their origin in the “weight” map, so IMHO you should run r.null on “weight” map, and then multiply it for the accumulation map.
In addiction, I also would check the projection, look at the resolution of your map… how do you set the resolution? It should be 30 according to elevation map. Maybe the resolution of “weight” map doesn’t match with the accumulation (and the elevation) ?
HTH,
madi
r.info dem.noweight.streams
Title: ( dem.noweight.streams )
Type of Map: raster Number of Categories: 0
Data Type: CELL
Rows: 1045
Columns: 1457
Total Cells: 1522565
Projection: Transverse Mercator
N: 28660140.36123598 S: 28628801.89941604 Res: 29.98895868
E: 549219.21981511 W: 505505.97596796 Res: 30.00222639
Range of data: min = NULL max = NULL
Data Description:
generated by r.stream.extract
r.info dem.weighted.streams
Title: ( dem.weighted.streams )
Type of Map: raster Number of Categories: 0
Data Type: CELL
Rows: 1045
Columns: 1457
Total Cells: 1522565
Projection: Transverse Mercator
N: 28660140.36123598 S: 28628801.89941604 Res: 98895868
E: 549219.21981511 W: 505505.97596796 Res: 30.00222639
Range of data: min = NULL max = NULL
Data Description:
generated by r.stream.extract
Comments:
r.stream.extract elevation=“dem_proj” accumulation=“dem.weighted” th
reshold=1000 d8cut=infinity mexp=0 stream_length=0 stream_rast=“dem.
weighted.streams”
What might I have done incorrectly now? Again, each step followed the
r.stream.extract example with the addition of running r.null on the
accumulation map.