[GRASS-user] WPS with GRASS and PyWPS
razmjooeis at faunalia.co.uk
Wed Oct 26 16:53:42 EDT 2011
Thanks for your through inspection. That part of UK is flat with lots of
artificial drains and canals. There is a loop river and also 2 parallel
channel. The DTM doesn't look great either and I think streams have not
been extracted properly in r.watershed.
On 26/10/11 21:07, Valentin Wittich wrote:
> Hi Saber,
> could you recreate the wrong calculation I've get with the point
> (527714, 328638). The point is a little above the connection to the
> tributary, could it be that the snap function doesn't work proper?
> On 10/26/2011 12:08 PM, Saber Razmjooei wrote:
>> Many thanks for your feed back.
>> The DTM is quite old (over 20 years) and very coarse (50 metre..but
>> region setting is I think 100 metre).
>> The reason you don't see the point is that it doesn't use the point
>> and it
>> uses another one snapped to the stream (r.watershed output). But we
>> definitely add something to show the point, either user input or the
>> snapped one.
>> In terms of validation, we have Flood Estimation Handbook which
>> unfortunately is not free and using the same DTM in our WPS. For
>> reasons there is no vector output from FEH either. So you need to create
>> screenshots. I don't have a license for it.
>> There will be more bells and whistles to it (hydrological parameters:
>> urban extent, main drain slope, max min elevation, etc).
>>> Nice tool, I like it!
>>> Three things came up in my mind when I used it.
>>> 1) After I selected a point and press calculate I couldn't see any more
>>> the point I selected...
>>> 2) It seams like there are some wrong calculation. For example for the
>>> randomly chosen point (527714, 328638). And the catchment border could
>>> be a little smoother ;)
>>> 3) I can only select a visual point, it would be nice to select the
>>> point by coordinates... it would be more useful.
>>> Did you try to validate your data with a independent dataset? I know
>>> from France there exists free hydrological surface catchments shapes
>>> over the whole country maybe it possible to make a validation with
>>> public DEM-data like SRTM.
>>> regards Valentin
>>> On Oct 26, 2011 9:27 AM, "Saber Razmjooei"<razmjooeis at faunalia.co.uk
>>> <mailto:razmjooeis at faunalia.co.uk>> wrote:
>>> Dear list
>>> We have developed a Web Processing service for calculating
>>> outlines in UK using GRASS and PyWPS:
>>> Any feedback is appreciated.
>>> grass-user mailing list
>>> grass-user at lists.osgeo.org<mailto:grass-user at lists.osgeo.org>
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