AN INNOVATIVE IMPACT ASSESSMENT

Coastal development is generally assessed subjectively, by considering the integration in the landscape of the reclamation, and pragmatically, by highlighting the economic advantages generated. A further type of assessment is called for: that of the impact on coastal ecosystems caused directly by reclamations from the sea.

The extent of of reclamations from the sea, compared to the original surface area and length of coastline, provides a basis for reliable quantitative assessment:

• of the main ecological impact of reclamations resulting in the irreversible destruction of the shallow bottoms concerned,
• of the landscape impact, taking into account the rate of artificialised coastline. Seen from the sea or the land, the coast offers a view of piles of blocks of rock, interlocking concrete tetrapods or vertical concrete jetties.

This process was initially undertaken in the 1970, but using manual calculations that were difficult to update. Assessments were also published for the Alpes-Maritimes (Meinesz, 1976 ; Meinesz et Lefevre, 1978), the Var (Meinesz et al. 1981), the Bouches-du-Rhône (Meinesz et al. 1982) and Corsica (Meinesz et al. 1980) with surveys for the Provence-Alpes-Côte d’Azur Region (Meinesz et al. 1990 et 1993). The data presented here is therefore an update of these data, extended to cover the whole of the French Mediterranean coast, including the shores of the Etang de Berre and the Principality of Monaco.

A new system for collecting data has been applied using a Geographical Information System (GIS) coupled with computer data processing with online access (Internet) to the data produced.

 The data base designed by MEDAM (Meinesz et al. 2006) has been constantly updated (new reclamations identified) and improved over the years (Meinesz et al. 2010) by the addition of:

• an image bank of photos of reclamations or of the coast prior to redevelopment,
• historical data on redevelopments on reclaimed land (providing a basis for drawing histograms showing the progression of impacts),
• better online access to data at the new website: the database now uses opensource technologies (PHP/MySQL) allowing greater flexibility of use and ensuring the security of the original data,
• better cartographical presentation based on the IGN Geoportail database.