A NUMERICAL BEACH EVOLUSION MODEL FOR SHOALING CHANNEL AND HARBOR IN SMALL PORT CONSIDERING THE EFFECT OF LONG PERIOD WAVES AND REEF ZONE

Abstract

 For the purpose of improving the conventional numerical model of predicting sand deposition in small harbors, field investigations were conducted focusing on long-period waves in addition to winter wind waves. In the field survey, the occurrence of long-period waves in the harbor was investigated. The results of the filed investigations were used to analyze the flow due to long-period waves around the harbor, and then the calculations of topographic changes around the harbor were attempted. The small harbor in the target area has a mixed topography of sandy zone, reef zone and breakwaters. Therefore, the influence of the reef zone into the calculation of bottom topography changes were adapted.

 As a result, drifting sand in the reef zone was suppressed, and erosion due to the influence of waves and currents behind the breakwater developed. Sand deposition around the harbor mouth and at the back of the harbor was reproduced, and the results were closer to the actual phenomena.