COLLECTIVE MOVEMENT OF DUNE-TYPE SAND WAVE IN SURF ZONE
近岸带水下沙丘的群体运动

Collective movements of sand wave in surf zone are distinguished into two groups: "bar-type" and "cusp-type", as pointed by C. J. Sonu. Based on the field observations off, the Shahgdong coast, this paper presents a new type sand wave called "dune-type". This type forms on the foreshore bed and moves only in the onshore direction, the height, width and storage of this sand wave all increase with time, then, "dune" approaches to the shoreline.Although the dynamic reason for this phenomenon is not so evident, this paper investigates the relationships between longshore energy flux of breaking waves (P1s) and the resulting migration distance (R), and sediment storage (Q) of dune-type sand wave experimentally. The results indicate that the R and Q are directly proportional to the P1s.