[Talk-es] Revising the border between Spain and Portugal

[Iván Sánchez Ortega]

El Jueves 9. abril 2015 12.21.12 Marcos Oliveira escribió:
> I'm also looking for the official data you use to map Spain's
> administrative limits

What you want is the files for "Líneas Límite Municipales" from here:

http://centrodedescargas.cnig.es/CentroDescargas/equipamiento.do?method=mostrarEquipamiento

Be aware that Spain doesn't have one "true" set of boundaries. Some 
municipalities have different data than the regional goverment, which might 
have different data than the national government. Usually the difference is no 
bigger than a few meters in the worst case.

Submeter accuracy for boundaries doesn't seem like a big problem, until you're 
faced with the problem of taxing buildings & constructions which lay exactly 
on a boundary (e.g. http://www.openstreetmap.org/#map=19/40.78820/-4.00284 - I 
know, first-hand, that there was a small dispute between regional governments 
about who should tax one of the water depots there)

If you want to be extra accurate, you'll have to survey the boundary 
milestones along the border, recalculate river centerlines and try to match 
everything to old documents.

Speaking of disputes and old documents, what's your point of view about 
Olivenza? I suggest you get up-to-date on how to tag territorial disputes in 
OSM.


> As a closing note, I'm writing this in English because I'm afraid I'd do a
> lot of grammatical errors and be misunderstood if I wrote in Spanish. To
> identify myself, I'm ViriatoLusitano. [1]

Vc pode falar portunhol, a gente vai comprender ;-)


-- 
Iván Sánchez Ortega <ivan en mazemap.no> <ivan en sanchezortega.es>