2. The Data

2.1 The DEM

The DEM for the study area was clipped from the DEM of Catalonia generated by the ICC (Institut Cartogràfic de Catalunya) from contour lines included in the Topographic map of Catalonia at 1:5000 scale produced by the same institution. Presented in ASCII format, this DEM has a 30 x 30m resolution and a RMSE (root-mean-squared-error) of 1.39 metres. That error, estimated by comparing elevations in 7606 points of Catalonia, has not been checked in areas of complex morphology, difficult access or in forests.

2.2 Digital cartography

The layers showing hydrography and contour lines that appear on the maps are part of a topographical digital base of Catalonia produced at a scale of 1:25,000 by the ICC.

2.3 The sites database

The sites database is the result of previous work carried out in the study area within the collective Forma Orbis Romani project, a research program about ancient Roman landscapes from the Institut d'Estudis Catalans. The work team, directed by Professor Josep Guitart, comprised Ignacio Ferrero, Oscar Matas, Martí Grau, Ester Gurri and myself (Guitart et al. forthcoming).

2.4 The roads network

The main roads of the study area have been digitised from Instituto Geográfico Nacional maps at 1:50,000 scale. Two major arteries that run parallel to the sea have been drawn following the descriptions given by Olesti (1995, 237-57) and Palet (1997). Three main natural corridors at right-angles to the sea have also been delineated (Professor J. Guitart, pers. comm.). Any errors are, of course, entirely those of the author.


© Internet Archaeology/Author(s) URL:
Last updated: Tues Mar 04 2008