SURFACE SEDIMENT DISTRIBUTION PATTERNS ON MIXED BEACHES IN RESPONSE TO WAVE CONDITIONS

摘要

Spatial patterns of surface sediment distributions on a mixed beach are measured using a new survey methodology, across three beach sections at Pevensey Bay, south east England. Spatial patterns in distribution and composition are related to antecedent hydrodynamic conditions and beach topography. Results indicate that higher energy waves produce a beach surface with a more homogenous grain size distribution, in contrast lower energy waves produce surfaces that are more mixed. In addition under storm conditions, a ‘type’ beach response was observed, consisting of a fine upper and coarse lower beach face. The high tide berm is shown to be composed of finer material than the beach material below. The survey method described is considered appropriate to measure surface sediment distribution patterns on mixed beaches, over large areas, on a tidal time-scale.