Mapping Nature-based Marine Flooding Risk using VHR Wave, Airborne LiDAR and Satellite Imagery: The Case Study of the Dol Marsh (Bay of Mont-Saint-Michel, France)

Abstract

Mury, A.; Collin, A.; Jeanson, M.; James, D.; Gloria, H.; Pastol, Y., and Etienne S., 2020. Mapping nature-based marine flooding risks using VHR wave, LiDAR, satellite: The case study of the Dol Marsh (Bay of Mont-Saint-Michel, France). In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 743-747. Coconut Creek (Florida), ISSN 0749-0208.A growing interest in nature-based solutions has gained unprecedented attention in the coastal risk management, to complement or replace conventional approaches like hard structures (dykes, seawalls, breakwaters). However, due to the diversity of coastal ecosystems and the heterogeneity of the ecosystem service of wave attenuation they can induce, the integration of their protective role in an accurate way into risk studies remains rare. This paper shows an experimental methodology to integrate this ecosystem service into the risk mapping at very high spatial resolution using in situ sensors, airborne LiDAR and spaceborne satellite imagery. Risk study is achieved using a combination of indices which allows to evaluate the asset's exposure and vulnerability. The nature-based solution is also integrated through the creation of an adaptive capacity index, based on a spatially-explicit model of wave attenuation. The study enables to highlight the assets which are the most concerned by the marine flooding risk, using a synthetic risk index ranging from 0 to 1.