EVOLUTION OF THE SANDY BEACH IN HAIYANG

This paper discusses the evolution of the beach and its controlling factors in the nearshore area of Haiyang, using several methods including calculation of the incipient velocity of the sediment, mathematical approaches for coastal transportation of sediment, and mathematical modeling for beach evolution, based on the depth and grain size data and remote images. The results show that the beach of the study area is roughly in a state of dynamic equilibrium as a whole. It is difficult for the sediment to make incipient motion. Longshore transport caused by waves may move the sediment to ENE direction. Factors affecting the changes of erosion and deposition include sand supply from rivers, waves and artificial structures. The reduction of rivers runoff may cause the decrease in sediment input and increase the erosion of local coast. The construction of coastal artificial structures may change the migration path of sediment, and lead to the local changes in erosional and depositional patterns. Wave is a key factor in controlling sediment transportation and sedimentation. In conclusion, hydrodynamics is the factor controlling the overall evolutional pattern of erosion or deposition in the study area.