Write a PREreview

This study developed an innovative multi-data fusion framework combining remote sensing (Landsat and Sentinel-2 imagery accessed via GEE) and beach sediment grain size analysis to investigate coastal evolution at Dalian World Peace Park’s sandy tourist beach from 2000 to 2024. Coastlines were extracted using CoastSat after tidal correction and sub-pixel edge detection. DSAS analysis revealed a spatially differentiated pattern of northern deposition and southern erosion, dividing the area into three geomorphic units that deposition-dominated zones, dynamic equilibrium zones, and erosion-active zones. The 2008 land reclamation project altered local hydrodynamics, triggering an artificial headland effect. This caused substantial deposition in the northern region (maximum 74.16 m, progradation rate 4.95 m/yr) and erosion in the southern section (27.14 m), which exhibited nonlinear response characteristics. Ecological restoration projects using cobble structures enhanced sediment retention and wave energy dissipation, stabilizing shoreline changes. However, the 2017 double typhoon event resulted in finer sediment grain size and poorer sorting, causing instantaneous coastline retreat. This demonstrates that extreme climate events exert a strong short-term disruptive effect on coastline evolution. These findings provide a scientific basis for erosion control and beach maintenance on sandy tourist coasts in northern China.