NH8.1/GM5.13NH8.1/ GM5.13

Ecosystem-based approaches to coastal Disaster Risk Reduction: new tools and case studies (co-sponsored by IGU-CCS) (co-organized) 
Convener: Paolo Ciavola  | Co-conveners: Clara Armaroli , Jenny Brown , Pushpa Dissanayake 
Some of the major coastal disasters in the past decade have clearly demonstrated how nature has a primary role in reducing the impact of extreme coastal flooding events generated by storms, which produce a high cost to society as well as a threat to valuable ecosystems. After Typhoon Haiyan in the Philippines in 2014, the Government financed USD22 million for the restoration of mangroves along the affected coastlines as evidence grew showing that where coastal vegetation was present, this attenuated the magnitude of flooding. Similarly, following Hurricane Katrina the US government invested USD500 million for the restoration of coastal national parks and salt marshes, accepting the proofs that marshes helped to reduce the damage, in association with dike and levees. Thus, it is a prerequisite to propose that the reconstruction of ecosystems should be done before an event strikes, with a philosophy of prevention rather than a remedy, with a philosophy of recovery. In Europe too, many member states have started to promote the recreation of coastal wetlands, considering setback strategies as well as the reconstruction and vegetation of coastal dunes, which act as the first line of defence to flooding. As it is stated in the recently released EU-Science for Disaster Risk Management 2017 Report, a number of European Commission-funded demonstration projects are now supporting ecosystem-based Disaster Risk Reduction, to prove the added value of such an approach compared with traditional engineering solutions.

This new approach demands: the development of new tools to model and design these reconstructed environments; merging physical concepts like bed erosion and sediment transport with the parameterization of biologically-induced phenomena, such as the role of emerged and submerged vegetation in attenuating wave and current energy; as well as the role of plants in stabilising/destabilising the morphology of coastal dune systems.

The session welcomes contributions covering modelling and monitoring aspects, including innovative approaches in coastal morphological models that account for the presence of the ecosystems, quantifying feed-back interactions between the physical and biological components. We welcome case-studies reporting recovery of the ecosystems and of the physical environment following major extremes such as tropical and extra-tropical storms. We also welcome contributions on case studies documenting new techniques for revegetation of submerged as well as subaerial environments.