Caractérisation des habitats ripariens et du contexte écopaysager d'un petit fleuve endigué : le cas de la basse vallée de la Dives, Calvados (France)

The marshes and coastal areas of the river Dives, Calvados (France), are threatened both by water and sea level rises, coastal floodings and submersions as consequences of the global and local climate changes. The river Dives crosses this dyked marshland which covers nearly 10000 ha and whose impoldering dates since the 12th century. Local stakeholders are much concerned by the global decay of the dikes and wish to benefit from the expertise of a national research program (National Research Agency 2019-2023 DIGUES for Dikes, Interactions, Management, Uses, Environment and Scenario) in order to identify potential adaptation strategies. This exploratory research program aims at identifying natural and man-made habitats that cover the dikes and giving a better understanding of the evolutionary processes of this at-risk territory. The use of drone surveys and of a transect method over the landscape help determine disturbing elements that could have an impact on these flood protection structures. In addition to this alternative approach of habitat monitoring, this research gives the opportunity to establish different trend scenarios for the dikes of the river Dives that represent a central challenge in climate change issues.