[GRASS-user] announcement of strahler stream order analysis

Carlos Grohmann carlos.grohmann at gmail.com
Tue Jul 28 11:57:32 EDT 2009


Just tested in a LatLong region. works fine.

Carlos





2009/7/28 Jarek Jasiewicz <jarekj at amu.edu.pl>:
> try, I don't know I haven't  LL location to test it
> but it shoud work
> program do not use any inforamtuon about units and units conversion
>
> Jarek
>
> Milton Cezar Ribeiro pisze:
>>
>> Hi Jarek
>>
>> Can use this on a LatLong mapset where my unit is not meters?
>> Thanks for the effort!
>>
>> milton
>>
>> 2009/7/26 Jarek Jasiewicz <jarekj at amu.edu.pl <mailto:jarekj at amu.edu.pl>>
>>
>>    Hi list!
>>
>>    I just finish first version of new grass module r.stream. Module
>>    is regular Grass module, written in C an has no addational
>>    dependencies. It was compiled with GRASS65 devel  downloaded in
>>    last  two week. Source code you can find here:
>>
>>    http://heretic.livenet.pl/heretic/r.stream.tar.gz
>>
>>    Module compiles and seems to work. Analysis was tested only on one
>>    dataset.
>>
>>    To compile it copy r.streams directory to your grassXX../raster/
>>     cd r.stream run make and make install
>>
>>    What module calculate:
>>    - strahler stream order
>>    - shreeve stream magnitude
>>    - class of topological elements of drainage networks
>>
>>    Module use r.watershed outputs: SDF flow direction and SDF stream
>>    network.
>>
>>
>>    Analysis of r.stream shall be run on same regions setings as
>>    r.watershed. If no, run g.region rast=your_dir_file first. For now
>>    module do not check if region and rasters are identical. It is
>>    planned to add in nearest feature. It also do not check if dirs
>>    and streams are SDF result. Threre are no addational description.
>>    It will be added after testing.
>>
>>    It works only on cells data. Floating points data are not allowed
>>    (and have no sense).
>>
>>    Module is quite fast. 3000 x3000 cells all three analysis runs no
>>    more than 30 s. on AMD 3800 2GB, Ubuntu 8.04
>>
>>    Module is part of comprehensive project which will add full Horton
>>    analysis and some addational terrrains analysis to Grass. More
>>    details in the feature. Any cooperation is welcome. The next
>>    module I plan is directional vectorisation of stream network.
>>
>>    For now module is available only form web address pointed below.
>>    After testing and removing critical errors it will be added to
>>    grass add-ons (or maybe to main branch?).
>>
>>    Any coments, improvements and critics is very welcome.
>>
>>    More advanced Grass developers: Please check my code. Its funny,
>>    but I don't know C.
>>    General code is based on GRASS r.topindex module (by Keith Beven
>>    and Huidae Cho, strongly modified)
>>    Strahler stream order algorithm from Saga GIS (by Victor Olaya,
>>    modified)
>>    Shreeve stream magnitude and class of topological network are my
>>    own ideas
>>
>>    Test and enjoy.
>>
>>    Jarek Jasiewicz
>>    Adam Mickiewicz University, Poznan
>>    Geoecology and Geoinformation Institute
>>    _______________________________________________
>>    grass-user mailing list
>>    grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>
>>    http://lists.osgeo.org/mailman/listinfo/grass-user
>>
>>
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-- 
Carlos Henrique Grohmann - Geologist D.Sc.
a.k.a. Guano - Linux User #89721
ResearcherID: A-9030-2008

http://digitalelevation.blogspot.com

http://www.igc.usp.br/pessoais/guano
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