Thanks Stefan,
I guess I should have mentioned, the whole point of all this work is to
get the appropriate input data, including the topidx map required to run
topmodel for a two year period, on very small catchments (25km^2 ). I
can run either the GRASS or R version of topmodel, but it appears that
the R version is better equipped to do sensitivity analysis, i.e. pass
it a parameters file with multiple lines of parameters, through which it
will iterate and do the sensitivity analysis. I'm assuming this doesn't
change your advice?
Thanks
J
On 26/04/16 22:10, Blumentrath, Stefan wrote:
Hi Jim,
If I understood you final objective correctly, I would say 2: r.stream.basins,
will replace most of your workflow...
With the stream_rast option, r.stream.basisns produces basins using raster input maps
with "multiple outlets".
You can feed this option either with a raster map of your whole stream (which
naturally covers the outlet) or even specify categories of the streams you
want to get the basisns for. Citing from the manual:
To delineate one or more particular basins defined by given streams, add simply
stream categories:
r.stream.basins -lc direction=direction stream_rast=streams cats=2,7,184
basins=bas_basin
See also: https://grasswiki.osgeo.org/wiki/R.stream.*_modules and of course the
related scientific paper:
http://www.sciencedirect.com/science/article/pii/S0098300411000975
Hope that helps.
Cheers
Stefan
-----Original Message-----
From: Jim Maas [mailto:j.m...@uea.ac.uk]
Sent: 26. april 2016 15:44
To: Blumentrath, Stefan <stefan.blumentr...@nina.no>; grass-user@lists.osgeo.org
Subject: Re: [GRASS-user] simple way to get Easting and Northing coordinates of
stream outlet directly from r.watershed?
Hi Stefan,
Thanks for this. I've had a look but not tried it yet. Just for me to
clarify, are you suggesting that:
1. r.stream.basins will somehow produce and output the Easting and
Northing values of the overall outlet?
2. r.stream.basins, will replace most of this workflow and thus the
Eastings and Northings will not be required explicitly?
In the case of 1, I can't quite see how it will output these values?
Thanks a bunch,
J
On 26/04/16 14:02, Blumentrath, Stefan wrote:
Hi,
Did you consider using:
https://grass.osgeo.org/grass70/manuals/addons/r.stream.basins.html
?
Cheers
Stefan
-----Original Message-----
From: grass-user [mailto:grass-user-boun...@lists.osgeo.org] On Behalf
Of Jim Maas
Sent: 26. april 2016 14:28
To: grass-user@lists.osgeo.org
Subject: [GRASS-user] simple way to get Easting and Northing coordinates of
stream outlet directly from r.watershed?
I'm using GRASS 7.0.3 (text) on Ubuntu Linux, and running it either from a bash
shell script or from an R file.
I've worked out a workflow that does what I want, but it is very long and
convoluted, so I'm wondering if there is a simple way to extract the Easting
and Northing coordinates of the lowest point on the stream network, such that I
can then use them as inputs for r.water.outlet?
Here is my workflow, realise it is long
1. run r.watershed to get drainage, streams, and basin 2. run
r.stream.order to calculate strahler order and get strahler
raster map
3. use r.stats and some bash code to extract highest strahler number
from the strahler map
4. use r.mapcalc .... not sure why, inherited this bit from someone!
5. use r.stats to get data from stream dem into a text file 6. use some
bash and awk code to extract the Easting and Northing
values of the lowest point in the text file created from the stream dem
7. use r.water.outlet to create new drainage map for the basin 8. use r.lfp
to calculate longest flow path, also uses the Northing
and Easting values of the outflow point
So I guess what I'm looking for is a simpler way to get the Northing and
Easting values of the lowest point, directly from r.watershed or something
analogous.
All suggestions most welcome. Thanks
J
--
Dr. Jim Maas
University of East Anglia
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--
Dr. Jim Maas
University of East Anglia
--
Dr. Jim Maas
Mathematical Modelling in
Epidemiology of Infectious Disease
Rm 2.13 MED
Norwich Medical School
University of East Anglia
Norwich Research Park,
NR4 7TJ U.K.
E: j.m...@uea.ac.uk
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