[GRASS-user] Splitting Up an Area

[Moritz Lennert]

On 05/12/17 01:09, Joshua Quesenberry wrote:
> All,
> 
> Any suggestions on how best I could split up a region into 40-60 acre 
> segments using linear features (ridges, streams, roads, trails, etc.)? 
> The watershed tool seems to split along ridges and ravines fairly well, 
> however, it seems I can only define the lower area limit not the upper..
> 

Are you speaking about linear features in images, or about vector maps 
of linear features ?

If this is for images, what you are speaking about are cutlines. AFAIK, 
we currently do not have an implementation of cutlines in GRASS GIS. 
Attached you can find a bash script I threw together trying to implement 
a cutlines algorithm using i.zc and r.cost+r.drain. It is in a rough 
state, without any comments, and it works only moderately well. It also 
doesn't scale well as i.zc puts everything into memory. I will probably 
have to work on a better version in a few months, but if you or someone 
else wants to do it before, I won't complain ;-)

You should be able to run it as is in the North Carolina demo dataset to 
see the results.

Moritz
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