Long-Term Monitoring and Morphological Response to Repeated Beach Nourishments in a Critical Coastal Sector: Lido di Dante Beach, Emilia-Romagna, Italy

Among low-lying sandy coasts, where erosion represents a major challenge, artificial beach nourishment is extensively used as mitigation strategy. This study investigates the long-term morphological evolution of Lido di Dante beach (Northern Emilia-Romagna, Italy), a highly subsiding and erosion-prone coastal sector characterized by different configurations of rigid defence structures. The analysis is based on 12 multi-temporal topo-bathymetric survey datasets acquired between 2007 and 2025, covering the complete monitoring sequences of three regional nourishment interventions (Progettone 2, 3, 4). An integrated methodological approach combining sediment budget calculations, shoreline evolution analysis, cross-shore profile assessment, and beach slope evaluation was applied to characterize the morphological response of the nourished system. Results show a consistent post-nourishment response among the three interventions, with effective beach recovery followed by sediment redistribution from the subaerial and intertidal zones towards the nearshore. However, the morphological evolution showed marked spatial variability, reflecting the influence of coastal defence structures on sediment redistribution pathways. The findings highlight the need for repeated nourishment interventions to maintain long-term beach stability at Lido di Dante. Furthermore, the study demonstrates the importance of accurate long-term topo-bathymetric monitoring for evaluating nourishment performance and supporting adaptive coastal management strategies in complex coastal environments.