[GRASS-user] r.stream.basins vector outlets help (Jens Hegg)

Blumentrath, Stefan Stefan.Blumentrath at nina.no
Tue Feb 10 15:06:07 PST 2015


Hi Jens,

Sorry, my fault. I should have asked you about your platform first.
Assuming you are on Windows I guess python would be most suitable language for scripting. Unfortunately I am not that good at python, but I am sure others will fill in.
You might need something like:
points = grass.read_command("v.to.db", map='YOUR_VECTOR_POINTS", columns='', option='coor', separator=',', flags='p')
for p in points.splitlines():
	x=p.split(',')[2]
	y= p.split(',')[3]
	grass.run_comand('r.stream.basin', dirs=..., coors="%d,%d" % (x, y), ...)

Good luck!
Stefan

-----Original Message-----
From: Jens Hegg [mailto:jensenhegg at gmail.com] 
Sent: 10. februar 2015 21:22
To: Blumentrath, Stefan
Cc: grass-user at lists.osgeo.org
Subject: Re: [GRASS-user] r.stream.basins vector outlets help (Jens Hegg)

Sefan, 

Thanks for the help. I'm still not getting it to run, but I am not at all familiar with anything beyond running basic commands on the command console, I've mostly just used the GUI. Should these be input into the command console or the Python shell? I've tried both, the console seems to not recognize most of it, the Python shell gives me lots of syntax errors (which seems like a good start, I just don't know Python at all). 
Here is what I have:

points=$(v.db.select -c map=Fish_and_Water_PointsEPSG4140 column=cat)) for p in $points do
	v.extract --overwrite input=Fish_and_Water_PointsEPSG4140 output=temp_point_map cat=(p) type=point
	r.stream.basins direction=HenrysDrainage at HenrysFork points=temp_point_map basins=Basin_(p) done

The first error is a syntax error at the dollar sign in points=$(v.db.select... 

Am I getting close? The idea is that temp_point_map gets overwritten at each loop so all that remains is the last one. I'm wanting to name each new basin by the category so I can go back and figure out it's attribute data. 

Jens


On Feb 9, 2015, at 11:04 PM, Blumentrath, Stefan wrote:

> Hei Jens,
> 
> If you want to have watersheds which overlap, you have to have them in different maps as neither raster nor vector data with topology (as in GRASS GIS) allow for overlapping areas.
> That again means you would have to run r.stream.basins for your vector points individually, e.g. in a loop like this:
> 
> points=$(v.db.select -c map=mypoints column=cat) for p in $points do
> 	v.extract ...
> 	r.stream.basisns ... 
> done
> 
> Cheers
> Stefan
> 
> -----Original Message-----
> From: grass-user-bounces at lists.osgeo.org 
> [mailto:grass-user-bounces at lists.osgeo.org] On Behalf Of Jens Hegg
> Sent: 10. februar 2015 05:32
> To: grass-user at lists.osgeo.org
> Subject: Re: [GRASS-user] r.stream.basins vector outlets help (Jens 
> Hegg)
> 
> Ok,  I figured out how to make it work for the vector file. I was including both the flow direction and the stream network along with the vector file. It turns out that only the direction and vector outlets files are needed and then it runs perfectly. The manual examples really should be updated to include a vector points example.
> 
> I do still have one problem that someone might be able to help with. Many of the points I use for outlets are just downstream of one another so it creates watersheds that are just small slivers between points. Is it possible for it to create overlapping watersheds as you move down the stream, or do I need to go back and do this manually?
> 
> Jens
> 
> 
> 
> On Feb 9, 2015, at 6:08 PM, grass-user-request at lists.osgeo.org wrote:
> 
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