Prof. Athanasios Vafeidis (University of Kiel, Germany)
Title: Employing the DIVA modelling framework to develop coastal adaptation pathways for the Mediterranean basin
Host: UCF Coastal
Abstract: The high concentration of population and economic activities along the Mediterranean coasts poses significant challenges for adaptation to sea-level rise. Despite the existence of the Integrated Coastal Zone Management Protocol (ICZM) of the Barcelona Convention, which calls for a common approach to coastal management in the region; and a large number of regional and national programmes dedicated to climate-change adaptation issues in the region; no comprehensive and comparative assessment of coastal impacts of sea-level rise and associated adaptation needs has been so far carried out for the entire basin. To address this gap we employ the Dynamic Interactive Vulnerability Assessment (DIVA) modelling framework to assess the long-term (until 2100) impacts of sea-level rise and to explore the potential benefits of a range of coastal adaptation measures for the Mediterranean basin. We focus on coastal flood risk and erosion and evaluate the implementation of different adaptation options. For adaptation to coastal flooding we consider hard protection (in the form of dikes); setback zones, which are explicitly mentioned in the ICZM protocol; and accommodation, in the form of household-level adaptation measures. For adaptation to coastal erosion we consider beach nourishment. In order to effectively map the solution space we assess potential impacts under a range of physical (RCP 8.5 and 4.5) and socio-economic (SSP2, SSP3 and SSP5) scenarios. Further, we use the downscaled version of the DIVA global database, which contains the latest information on coastal physical and socio-economic parameters for the Mediterranean nations.
Our results suggest that adaptation in the form of hard protection or the combination of hard protection with setback zones reduces by several orders of magnitude both the number of people affected by floods and the damages to assets. Nevertheless, substantial initial investments are required for building dikes while hard protection may be undesirable in touristic areas. At the same time, the implementation of setback zones involves numerous institutional and governance challenges. Accommodation, in the form of implementing measures to reduce flood damage at household-level, can effectively reduce damage costs and is relatively easy to implement. Beach nourishment for countering coastal erosion is highly cost-effective under all scenarios. However, challenges arise with respect to future sand availability but also to the large number of small pocket beaches, particularly in the eastern part of the basin. Importantly, costs of protection are unevenly distributed between countries and amount to a significant proportion of the GDP for some Mediterranean nations. We conclude that a mix of protection by dikes and setback zones in unprotected areas, as well as beach nourishment, seem to be the most efficient strategies for reducing future impacts. We show how these results can be used as a basis for developing adaptation pathways for the Mediterranean basin. However, specific protection options for most vulnerable and densely populated regions, as well as for important places such as large ports and world heritage sites, will need to be considered and implemented.
Biographical Sketch: Nassos is Professor in Coastal Systems and Hazards at the Institute of Geography at Christian-Albrechts University Kiel (CAU) and the Future Ocean Excellence Cluster and leads the Coastal Risks and Sea Level Rise research group. He has a background in Surveying Engineering and received his MEng at the National Technical University of Athens. He went on to complete an MSc in Physical Geography at the University of London (King’s College) where he specialised in Geographic Information Systems and remote sensing. After a one-year break working as a consultant in the industry, he returned to King’s College where he obtained his PhD degree in Physical Geography. He then moved to the Flood Hazard Research Centre (Middlesex University) where he worked on the DINAS-Coast and Atlantis research projects. Before joining CAU he was a visiting researcher at the University of the Aegean (Greece) and at the University of Southampton (UK).
Nassos’s expertise and research interests lie in the field of natural hazards, with a focus on coastal areas. He has participated as a principal investigator in a number of collaborative research projects and has co-authored more than 80 peer-reviewed articles, book chapters and scientific reports. He has contributed to the Stern Review on the Economics of Climate Change and to the Fifth Assessment Report of the IPCC WGII and is currently a Co-ordinating Lead Author for the first Mediterranean Assessment Report.