Multi-Scale analysis of spatial and environmental changes along the Mezitli–Erdemli Coastal Corridor, Mersin Province, Türkiye

Coastal zones of the eastern Mediterranean are increasingly affected by urban expansion, agricultural transformation, coastal engineering, and water-quality degradation. Although shoreline change, land-use dynamics, and turbidity have often been examined separately, long-term integrated assessments that jointly evaluate geometric shoreline displacement, terrestrial pressure, and nearshore optical water-quality degradation remain limited, particularly along rapidly urbanizing Mediterranean coasts. This study addresses this gap by investigating the Mezitli–Erdemli coastal corridor of Mersin Province, Türkiye, between 1985 and 2025. Multi-temporal Landsat imagery was used to extract shoreline positions, classify land-use/land-cover change, and assess turbidity conditions. Shoreline evolution was quantified using the Digital Shoreline Analysis System through End Point Rate and Linear Regression Rate, while Mann–Kendall and Sen’s slope analyses were used to evaluate long-term trends and project shoreline tendencies toward 2035 and 2045. The results reveal strong spatial asymmetry along the coast: erosion dominated the eastern urbanized Mezitli–Yenişehir sectors, with rates reaching –5.8 m year⁻ 1 , whereas accretion prevailed in the western Erdemli sectors, reaching + 10.8 m year⁻ 1 . EPR and LRR showed very strong consistency across the six analysis zones, indicating that the dominant shoreline-change patterns were supported by the full multi-temporal shoreline record. Urban and agricultural areas expanded by approximately 190 km 2 , while open lands declined by 37%. A strong correlation between urban expansion and Normalized Difference Turbidity Index-derived turbidity variation (r = 0.95) indicates that land-based pressure is rapidly reflected in nearshore optical water-quality degradation. However, turbidity is interpreted as a complementary environmental indicator rather than a direct driver of erosion or accretion. The findings demonstrate that the Mezitli–Erdemli shoreline should not be managed as a uniform coastal unit. Instead, zone-specific and hybrid coastal-management strategies are required to address the coupled effects of shoreline mobility, land-use transformation, and nearshore water-quality change.