As an output from r.streams.extract, I'm getting a stream direction
map that is only along the stream network, and null everywhere else.
From the manual, it seems the direction map needs to be for the entire
study area. I am looking to feed the streams and direction map into
the r.stream.basins module.
Since I'm on GRASS 6.4RC5, I dont have MFD option in my r.watershed,
so I rely upon r.stream extract to output the stream network and the
direction map. I had seen a portion in the notes stating "Nowadays f
direction map comes from r.stream.extract must be patched by direction
map from r.watershed. (with r.patch).
I wouldnt think I could patch the SFD direction output from
r.watershed with the MFD stream direction map to create a direction
map for the entire study area. Is there another solution to use MFD?
As an output from r.streams.extract, I'm getting a stream direction
map that is only along the stream network, and null everywhere else.
>From the manual, it seems the direction map needs to be for the entire
study area. I am looking to feed the streams and direction map into
the r.stream.basins module.
Since I'm on GRASS 6.4RC5, I dont have MFD option in my r.watershed,
so I rely upon r.stream extract to output the stream network and the
direction map. I had seen a portion in the notes stating "Nowadays f
direction map comes from r.stream.extract must be patched by direction
map from r.watershed. (with r.patch).
I wouldnt think I could patch the SFD direction output from
r.watershed with the MFD stream direction map to create a direction
map for the entire study area. Is there another solution to use MFD?
if grass64 really do not have MFD (i'm suprised!) the only solution is to compile grass 65 from source
As an output from r.streams.extract, I'm getting a stream direction
map that is only along the stream network, and null everywhere else.
>From the manual, it seems the direction map needs to be for the entire
study area. I am looking to feed the streams and direction map into
the r.stream.basins module.
Since I'm on GRASS 6.4RC5, I dont have MFD option in my r.watershed,
so I rely upon r.stream extract to output the stream network and the
direction map. I had seen a portion in the notes stating "Nowadays f
direction map comes from r.stream.extract must be patched by direction
map from r.watershed. (with r.patch).
I wouldnt think I could patch the SFD direction output from
r.watershed with the MFD stream direction map to create a direction
map for the entire study area. Is there another solution to use MFD?
if grass64 really do not have MFD (i'm suprised!) the only solution is to compile grass 65 from source
grass64 has MFD in r.terraflow. You can use r.terraflow + r.dominant_dir.m + r.calc_terraflow_dir.m (grass-addons) in order to get the main drainage direction for MFD flow, use r.terraflow flow accumulation and the filled elevation map produced by r.terraflow as input to r.stream.extract, then patch the new flow directions into the main drainage direction extracted with the addon tools.
You can also use flow accumulation from r.watershed with SFD as input to r.stream.extract and patch the flow directions of r.stream.extract into r.watershed flow directions, these are compatible. But note ticket #807.
As Jarek said, best would be to use r.watershed in grass65 instead.
2009/11/16 Markus Metz <markus.metz.giswork@googlemail.com>:
Jarosław Jasiewicz wrote:
M S pisze:
As an output from r.streams.extract, I'm getting a stream direction
map that is only along the stream network, and null everywhere else.
>From the manual, it seems the direction map needs to be for the entire
study area. I am looking to feed the streams and direction map into
the r.stream.basins module.
Since I'm on GRASS 6.4RC5, I dont have MFD option in my r.watershed,
so I rely upon r.stream extract to output the stream network and the
direction map. I had seen a portion in the notes stating "Nowadays f
direction map comes from r.stream.extract must be patched by direction
map from r.watershed. (with r.patch).
I wouldnt think I could patch the SFD direction output from
r.watershed with the MFD stream direction map to create a direction
map for the entire study area. Is there another solution to use MFD?
if grass64 really do not have MFD (i'm suprised!) the only solution is to
compile grass 65 from source
grass64 has MFD in r.terraflow. You can use r.terraflow + r.dominant_dir.m +
r.calc_terraflow_dir.m (grass-addons) in order to get the main drainage
direction for MFD flow, use r.terraflow flow accumulation and the filled
elevation map produced by r.terraflow as input to r.stream.extract, then
patch the new flow directions into the main drainage direction extracted
with the addon tools.
You can also use flow accumulation from r.watershed with SFD as input to
r.stream.extract and patch the flow directions of r.stream.extract into
r.watershed flow directions, these are compatible. But note ticket #807.
As Jarek said, best would be to use r.watershed in grass65 instead.