PRESENT SCOURING AND SILTATION PATTERN OF THE SANDY BEACH IN EASTERN LIAODONG BAY

During 2013-2014, field investigation was taken on the two sides of the Liugu River in the Eastern Liaodong Bay. 6 investigation sites and 17 profiles were selected between Xingcheng and Suizhong. Results show that the studied beaches are mainly composed of reflective high-tidal beach, scarp, dissipative low-tidal beach with nearshore sand bars and underwater sand bars. During the investigation times, obvious erosional records were found in Nanjiangtun, Pijiatun and Xinlitun,and continuous erosion occurred at most of the profiles. The largest erosion rate came up to 53.2 cm/a according to our record. It is inferred that there exit seasonal or regional diversities in beach morphology variation and profile erosion/siltation rate. In winter,nearshore sandbars disappeared and the offshore distance of the underwater bars became shorter than that in summer. The erosion rate increased and accumulation rate decreased on the north of the Liugu River,and it is in opposite in the south. It is also found that the change of natural coastline shapes leads to the variation of longshore sediment transport. These variations are supposed to be the main natural cause of variation of erosional and siltation pattern. Local morphology variation is influenced by coast structures (especially jetties). Meanwhile,the diversity characteristics of waves led to seasonal or regional diversities in beach morphology variation and profile erosion/siltation rate.