MISEEVA : Set up of a transdisciplinary approach to assess vulnerability of the coastal zone to marine inundation at regional and local scale, within a global change context

C. Vinchon¹, N. Baron-Yelles², E. Berthelier³, C. Hérivaux¹, S. Lecacheux¹, C. Meur-Ferec⁴, R. Pedreros¹, H. Rey-Valette⁵ and B. Rulleau⁶

¹ BRGM
c.vinchon@brgm.fr ; c.herivaux@brgm.fr ; r.pedreros@brgm.fr ; s.lecacheux@brgm.fr
² LVMT
nacima.baron@enpc.fr
³ SOGREAH
emmanuelle.berthelier@sogreah.fr
⁴ Geomer
Catherine.Meurferec@univ-brest.fr
⁵ LAMETA
helene.rey-valette@univ-montp1.fr
⁶ REEDS
benedicte.rulleau@uvsq.fr

Abstract

MISEEVA (2008-2011) aims to assess coastal zone vulnerability to marine inundation by integrating the physical and socio-economical aspects at different temporal (2010, 2030 and 2100) and spatial (local to regional) scales. The Languedoc Roussillon (France) region was chosen as a pilot site, focusing on local sites from Villeneuve-lès-Maguelone to Carnon, in Hérault.

It required the development of a transdisciplinary methodology to enable transfers of knowledge and promote interdisciplinary iteration of methods throughout the project.

In 2030, sea level rise (SLR) should not exceed 0.07m (IPCC, 2007). For 2100, SLR of 0.35m (A2 SRES scenario, GIECC 2007) and 1m (Rahmstorf, 2007, Grinsted et al, 2009), are both considered. As negligible changes in storminess are expected (IPCC, 2007, Déqué, 2007), historical storms are therefore used as references to simulate exceptional inundations, in 2010, 2030 and 2100.

Regional and local propagation of wind-generated waves and surges (wave set-up and atmospheric surge) are calculated using a chain of models and semi-empirical formulas. Then, maps of permanent, recurrent and exceptional inundations (due to SLR, tidal level, and surges) in 2010, 2030, and 2100 are drawn.

Socio-economy in 2030 is believed to follow the present day trend in Languedoc-Roussillon (demographic growth, urbanisation and tourist development). Socio-economic evolution in 2100 is quite unforeseeable: scenarios for 2100 are being built based on contrasted potential adaptation strategy scenarios

Designing a typology and valuation of present day assets help to value potential damages processes due to marine inundation on the coastal system at 2010, 2030 and 2100. Perception and response capacity knowledge to marine inundation risk is gained through residents, users and stakeholder surveys at the local site.

Mixing physical and socio-economical approaches to evaluate the exposure of a territory to a hazard allows progression towards a systemic definition of vulnerability. Projection in the future points out the need to consider adaptation capacity as a main parameter of vulnerability evolution.