[postgis-users] river network
kneufeld at refractions.net
Wed Feb 18 14:36:51 PST 2009
I just spent the last 5 years doing this exact thing for the BC Government - mapping all hydrographic data across BC,
(which they are now giving away for free :) ). The development was all done in PostGIS, spanning 150GB in tables. It's
Have you tried simply querying which stream segments spatially touch your specified segment?
-- Assuming your dataset is properly noded, directionalized
-- and digitized in a downstream direction, this will find
-- all streams that enter into stream with id = 1
FROM streams a, streams b
WHERE a.stream_id = 1 -- your specified segment
AND a.the_geom && b.the_geom
) = 0;
There is also an interesting concept where you can attribute the stream segments with a precomputed "hierarchical key".
Once done, you can quickly query all streams that are upstream of a given segment ... non-spatially.
This very old document may be of some interest to you.
The doc came from this site
> Dear Bruce,
> I need to query which river segment flowing into a specified segments.
> best regards,
> ----- Original Message ----- From: "Bruce Rindahl" <rindahl at lrcwe.com>
> To: <storma-ipb at indo.net.id>; "PostGIS Users Discussion"
> <postgis-users at postgis.refractions.net>
> Sent: Thursday, February 19, 2009 12:02 AM
> Subject: Re: [postgis-users] river network
>> Do you need to perform routing or some other analysis on the network?
>> storma-ipb at indo.net.id wrote:
>>> Dear List,
>>> does anyone has experience or references on how to store river
>>> network segments of a watershed in Postgis database?
>>> indomail - Your everyday mail - http://indomail.indo.net.id
>>> postgis-users mailing list
>>> postgis-users at postgis.refractions.net
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