[GRASSLIST:1079] sum of vector lengths within a polygon

[Rado Bonk]

Hi GRASSusers,

I'm working on the project where I need to know the total length of the
channels within a watershed. The area of Slovakia was divided into 1386
polygons, and valley bottoms coupled with active channels represent
vectors. How to find the total length of vectors within the polygon? Did
anybody use it in a any hydrological application?

Also, I would like to characterise each polygon by an unique number (or
two numbers) based on its morphometric properties. What parameter would
be suitable (hypsometric integral?)?
Basically I need to divide the polygons (lets say watersheds) into
several groups based on its morphometric properties.

Thanks in advance,

Rado


-- 
Radoslav Bonk M.S.
Dept. of Physical Geography and Geoecology
Faculty of Sciences, Comenius University
Mlynska Dolina 842 15, Bratislava, SLOVAKIA
tel: +421 905 968 127 e-mail: rbonk at host.sk