Sediment Quality for Enhanced CVI Assessment and Environmental Management in Mediterranean Micro-Tidal Coasts

The preservation of littoral zones faces escalating challenges from global thermal forcing and anthropogenic pressure, particularly in vulnerable basins like the Mediterranean. This research proposes an expanded Coastal Vulnerability Index to assess 253 km of beaches across the Valencian Community (Spain), integrating sediment durability parameters for the first time. Methodologically, an arithmetic mean of ten physical, biotic, and sedimentological indicators was employed, including a novel Sediment Quality Classification Index (SQCI) derived from accelerated particle wear tests as a key resilience indicator. Results reveal that 40.9% of the coastline exhibits high or very high risk, reaching critical levels in the province of Valencia due to key driving factors such as a 91.8% proportion of fine sediments and the severe degradation of its dune systems. Conversely, the presence of Posidonia oceanica meadows in Alicante acts as a key resilience factor. It is possible to conclude that the mechanical quality of sediment is a determinant for the longevity of protection measures, highlighting the necessity of transitioning from rigid infrastructures towards ecosystem-based adaptation to enhance regional resilience.