GIS and Viewshed Analysis to
Determine Sensitive Coastal Areas.
Case study from the French Riviera (France)

Samuel Robert

UMR 6012 ESPACE, CNRS - Université de Nice Sophia Antipolis (F)

Abstract

Within the frame of integrated coastal zone management, this work is dedicated to the identification of sensitive coastal areas through viewshed analysis. Because they are submitted to sea viewing, coastal lands often fall under the covetousness of land speculation. Real estate economy is indeed a major threat, for everyone would like to enjoy sea watching from its own appartment... The idea that coastal sceneries are a ressource of public importance is the main reason why GIS and viewshed analysis should be implemented into any coastal zone management programmes.

Using GIS capabilities and an appropriate geographical database, the poster shows how to characterize sensitive coastal areas, from the sea watching point of view. The area of study is the French Riviera (Côte d'Azur), namely the littoral of two provinces (départements), Var and Alpes-Maritimes, on the Mediterranean coast of France. There, tourism industry is one of the most developped in France and urbanisation has been sprawling over drastically. On these coasts, more and more, locals and tourists are deprived from sea watching because of urbanisation.

Within a 5 km wide strip of coastal land, we have calculated an exposure indice which quantify how much sea can be viewed from land. A specific treatment have been made to take into consideration the fact that coastal maritime areas and the open sea are not perceived the same by human eye. The result is a map along with a dataset allowing :
the identification of areas submitted to sea viewing
the quantification of how well exposed to the sea these lands are
data crossing and spatial analysis with other geographical data, such as land use at different periods of time, real estate, population and tourist industry statistics, etc.