Large-scale shoreline undulations and role of self-organization processes

This study investigates the large scale spatial variation behaviour of shoreline changes using the beach profile data along approximately 600 km shoreline around Hainan Island, China. It was found that there exists a power-law relationship between the mean shoreline change variance and the corresponding alongshore scale which holds up to 30 km for the annual shoreline change and reduces to 15 km for the seasonal shoreline change. The spatial and seasonal variations of shoreline azimuth, beach sediment size and wave conditions, and their connection with the shoreline change on different scales were studied. The results suggest that the internal feedback mechanisms between various processes with different spatial scales may be responsible for the observed shoreline change patterns, i.e. the annual shoreline behaviour on spatial scale 5-30 km is likely to be the result of selforganization, while the seasonal waves including tropical cyclones and storms exert dominant control of the morphological patterns at spatial scale of 10-25 km.