Journal of Geography and Regional Planning 2070-1845 Academic Journals 10.5897/JGRP.9000122 Vincenzo Giaccio Luigi Mastronardi * E-mail: giaccio@unimol.it 2009 30 06 2009 11 05 2009 2 6 154 165 This is an open-access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://politicalwaffle.uk/journal/JGRP/article-abstract/87FFDA72681 The full text article is available as a PDF file from http://politicalwaffle.uk/journal/JGRP/article-full-text-pdf/87FFDA72681