[GRASS-dev] Streams extraction from streams map

[Michael Barton]

Markus,

I remember that someone recently wrote a module that will calculate stream
Strahler order. This may well have code that you can use for this task,
since it must calculate whether or not a stream segment has 'tributaries'. I
think that it's posted somewhere--WIKI, Grassaddons, ?

Michael


On 5/2/07 2:04 AM, "Markus Neteler" <neteler at itc.it> wrote:

> On Tue, May 01, 2007 at 12:37:15PM +0200, Markus Neteler wrote:
>> Hi,
>> 
>> I have a network of streams (say, Spearfish or better the new
>> NC data set at http://mpa.itc.it/grasstutor/data_menu3rd.phtml )
>> and want to extract a single stream system. Names are lacking,
>> is there any trick to extract topologically connected lines
>> into a new map?
> 
> Probably we need some equivalent to the "sides" operator in
> v.to.db (which tells you the cats of the left and right polygon).
> Some magic which finds the lines which are connected and writes
> out some related attribute(s).
> 
> Ideas welcome,
> Markus
> 
> 

__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton