Study On The Storm Effect Of Sedimentary Geomorphology Of Fujian Sandy Beaches

On the basic of the former researches of the typhoon and storm tide's effect on the sandy beach, and by investigating geomorphology and sampling of the sandy beach of the coast of Fujian, this paper compared and analyzed the beach profiles' change on either morphology or sediments feature during No. 0418 typhoon "Aere" landing, and tried to find some response rules of the beaches, which may be used for reference when the government making a rapid prevention measure against the typhoon damage. The study indicates that rather violent morphology and sedimentary response occurred on Fujian beaches when "Aere" passed by at the end of August, 2004. The landform profiles eroded in general but several sections aggradated. The backshore dunes' retreating, the berms' lowering, and the shoreline's moving landwards was the main response feature of the profiles. The sediments' budget decreased in the volume. On the sediments feature of Fujian beach profiles, the surface layer consisted of mainly fine sand and fine-mid sand, and the bottom layer consisted of mainly mid sand and mid-course sand. Response to "Aere", each layer of sediments tended to be coarser and the gravel's content increased. The sediments' sorting became poorer and the granularity distribution frequency curves mostly changed from single-peak to double or multi-peak. These phenomena indicated that the beaches sediments had a tendency of granularity mixing, recomposing and redistributing under the storm waves and tides.