[GRASS-user] Query: number of 'areas' reported in v.build output does not necessarily represent different geographical areas

Nikos Alexandris nik at nikosalexandris.net
Mon Jul 29 05:53:40 PDT 2013


Nikos Alexandris wrote:
> > > > I tried to import USGS' (2011) Global Mangroves map:
..

Markus Metz wrote:
> > > I assume the global mangroves map should not have overlapping
> > > polygons, therefore as long as there are overlapping areas and/or the
> > > number of centroids is not equal to the number of input polygons, more
> > > cleaning is needed.
 
Nikos A:
> > Unfortunately it seems there are overlapping polygons.
..
 
> > I will search the respective documentation tonight to find stuff related
> > to minimum area extent -- maybe this can help (?).

> I can't find more than a short description of the production process and
> basic geo-referencing information
> (<http://data.unep-wcmc.org/datasets/21#fn2>). I will try to search more
> and perhaps gain contact with the responsible organisations UNEP-WCMC and
> USGS.

For the records,

I had an e-mail exchange with Chandra Giri (last month actually), the man 
behind the wonderful work of the Global Mangroves map. I informed that the 
Shapefiles contain many duplicate entries, as indicated by GRASS' import 
process.

Nikos


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