[GRASS-user] [GRASSLIST:9108] Re: Area size of a vector layer..

[Nikos Alexandris]

HamishB wrote:
> 
>> I got a SHP surface vector layer and inside i got 4 categories of
>> surfaces  (each one splitted in smaller area spread on the map): I
>> need to know the  total cover extension for each category.
>> How can I?
> 
> as mentioned, v.to.db will do it, but in GRASS 6.1, v.report is a bit
> easier.
> 
> d.vect + d.what.vect might help too!
> 
> 
>> on the attributes table i haven't any information on surface
>> extension.
> 
> I don't understand what you mean. 
> ?
> 
> 
> Hamish
> 
> 
> 
> 

I am replying in an old thread but I've been trying to grab area size per
class from a (CORINE land cover) vector map. Still no luck for a quick and
easy way.

So far I have uses the following (which do not sum-up area on a per-class
basis)

a. v.report BurnedAreas_TS3_25ha_CLC2000 option=area units=h | sort -n | tr
"|" "," > BurnedAreas_TS3_25ha_CLC2000.csv

b.  v.to.db -p map=BurnedAreas_TS3_25ha_CLC2000 type=boundary option=area
units=h columns=area_ha

or 

"v.to.db" with "-pc" instead of only "-p"

(any sql magic here?)

c. with starspan: not sure how to go about it for vector only stats

d. rasterising involves to make a decision for the resolution and (I think)
a different way of calculating the areas (maybe the estimates will be
overestimated or underestimated comparing with the vector polygon-stats).

So, what's the easiest way to do this calculation?

-- 
View this message in context: http://www.nabble.com/-GRASSLIST%3A9100--Area-size-of-a-vector-layer..-tp8631035p15950777.html
Sent from the Grass - Users mailing list archive at Nabble.com.