[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
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>>
>>
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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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