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| GeoCommunity Mailing List |
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| Mailing List Archives |
| Subject: | GISList: Extracting rivers from DEMs |
| Date: |
10/19/2001 06:16:59 AM |
| From: |
ðÅÔÒ ûÁÒÙÊ |
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Hi listers,
There were several questions (Randy Nattis, Xiaobo Zhou) on how
to extract rivers from a DEM. The best way I know is to calculate
so called catchment area from a raster DEM (i.e., grid).
Look at catchment area map image at this URL address:
http://members.fortunecity.com/eco4/giseco/
Catchment area maps provide both real and potential (dry) rivers
not distinguishing them. These maps are good at large scales,
but may produce false depressions at small scales, that is, at grid
meshes greater than characteristic valley widths (usually 100-200m).
Catchment area is implemented in ARC/INFO for Silicon Graphics,
see the above-mentioned Web site for corresponding PC-software
that can be used with ArcView or ARC/INFO.
Hope this will appear helpful.
Peter Shary
>From:"Nattis, Randy" <Randy.Nattis@ttemi.com>
>To:gislist@geocomm.com
>Date:Wed, 17 Oct 2001 08:27:13 -0700
>Subject:GISList: surface runoff flow
>
>Any advise on this one?
>
>I am using 30m DEM's to try and derive surface runoff of a landfill (I have
3d and spatial analysis, plus I'm using AV 3.2). I'm trying to prove that
the surface runoff is in a certain direction i.e., river. I've been
searching around for some scripts to assist me, but haven't found anything
quite right. I'm looking for something that will supply different length
arrows depending on the slope and direction (or something like this). I
would program some avenue code, but I do not have the time. Any insight on
this would greatly be appreciated.
>
>Thanks in advance,
>
>Randy Nattis
>
>From: Xiaobo Zhou <xizhou@vt.edu>
>To:gislist@geocomm.com
>Date:Thu, 18 Oct 2001 13:11:28 -0400
>Subject:GISList: Match DEMs to extract river network
>
>Hi all,
>
>I have to use Two (maybe more) DEMs together to extract river networks in
ArcView3.2. The question is how to match them precisely. Does anyone has
similar experience? Any advise would be greatly appreciated.
>
>Thanks in advance.
>
>Zhou
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