Assessing dune development potential for coastal resilience
Abstract
While coastal dunes represent one of the most straightforward NBS for enhancing coastal protection against natural hazards under both current and future climate scenarios, it is essential to determine where and under which conditions they can be most effective. To address this challenge, a coastal dune index-based framework has been developed. This tool assesses coastal areas to identify where the necessary conditions exist for dunes to function effectively as an NBS across different temporal scales.
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ASSESSING DUNE DEVELOPMENT POTENTIAL FOR COASTAL RESILIENCE Carla Garcia-Lozano1); Saverio Fracaros2); Rut Romero-Martín3); Cinzia Leccardi2); Annelore Bezzi2); Daniela Ciccarelli4); José Jiménez3) 1)Universitat de Girona, Spain; 2)Università degli Studi di Trieste, Italy; 3)Universitat Politècnica de Barcelona, Spain; 4)Università di Pisa, Italy COASTAL DYNAMICS 2025 7-11 April, Aveiro, Portugal ISand IAdaptability IDune IHazards ISand IAdaptability IDune IHazards how? The indicator considers factors of the beach-dune systems like adaptability capacity (IAdaptability), dune development (IDune), sediment supply (ISand) and hazard impacts (IHazards) allowing a quantitative measure of dune development potential. While rigid coastal defenses are still necessary in certain contexts, there is growing interest in nature-based solutions that not only enhance coastal protection but support ecosystem restoration. Coastal dunes play a crucial role in reducing coastal risks and enhancing resilience to climate change. They also provide vital ecological functions and contribute to the recovery of the original coastal landscape. Effectively addressing these challenges requires a multidisciplinary approach within an eco-morphodynamics framework. why? While coastal dunes become one of the simplest NBS for enhancing coastal protection against natural hazards in both current and future climate scenarios, it is essential to identify where and under what conditions they will be effective. To tackle this challenge, a coastal dune index-based framework has been developed. This tool evaluates coastal areas to determine where the necessary conditions exist for dunes to function effectively as an NBS over specific time scales. what? Aeolian transport Beach width Granulometry ISand IHazards Coastal evolution Storm erosion Storm flood Sea level rise IDune Foredune evolution Dune width Dune length Dune height Dune fragmentation Veg. cover in front-dunes Veg. cover in back-dunes Veg. cover in stabilised dunes IAdaptability Accommodation space Land uses Inland slope Deconstruction feasibility Built-up areas affect the ability of dune systems to move inland during erosion events. Adaptable urban features such as promenades or parks can potentially be relocated, reflecting a strategic and flexible approach to coastal management. Natural coastal dynamics, particularly sediment transport and storm events, are reshaping shorelines through erosion or accretion. Future shoreline retreat due to extreme storms and sea level rise, offers a comprehensive understanding of coastal risks under current and future climate conditions. Beach width, sediment characteristics, and wind conditions are key factors in dune formation and development. Understanding these dynamics is essential for effective coastal management and the promotion of natural defenses. Foredunes play a vital role in protecting coastlines from sea-level rise and storm impacts. Their evolution over recent dècades as well as their currently dimentions reflect the overall health and conservation status of the dune system. Vegetation cover is crucial for stabilizing dunes, with pioneer species in the foredune and mature vegetation in the backdune both contributing to coastal resilience. Each block’s variables have been rescaled from 1 to 5, and an average score has been calculated per block. This enables comparison across blocks to determine whether they reflect positive or negative conditions regarding the parameter assessed. In the case of IDune, the score reflects the actual level of dune development, not its potential. positive negative Ilustrated by: Catalonia, Spain [Gulf of Roses - Pilot area] Upper Adriatic, Italy [Lignano – Pilot area] Demo sites The indicator will be applied along the 600 km of the Catalan coast (Spain) and along the 145 km of the Northern Adriatic (Italy). Below is an application of the indicator in two pilot areas. This research has been funded by the European Union granted by the NextGeneration EU, project “Interconnected Nord-Est Innovation Ecosystem iNEST” (CUP J43C22000320006); by the European Commission granted under the call of the Horizon 2020 project IMPETUS (101037084); and by MCIN/AEI/10.13039/501100011033 and the “European Union NextGenerationEU/PRTR” project CoastSpace (TED2021-130001B-C22). ISand IAdaptability IDune Ihazards: work in progress…