摘要
本文利用近几年的水深断面与区域测深资料分析了苏北废黄河三角洲突出部位海底在防波堤建设前后的冲淤变化特征.研究结果表明,废黄河水下三角洲在防波堤修建之前已达到准平衡状态,并形成水下斜坡和海底平原地貌单元,斜坡侵蚀下限在-15m水深.防波堤建成后水下斜坡和海底平原受到侵蚀,斜坡侵蚀下限下移到-16.7 m而稳定.其中侵蚀严重区主要发生在两侧防波堤的根部、堤头及北堤转折处,最大冲刷深度超过2m;淤积部位出现在南堤中部和防波堤内,其中南堤中部淤积量在1～2 m之间,而堤内淤积厚度在0～6 m左右,堤内净淤积量为4.9×106 m3,占总淤积量的65％.数模结果显示,防波堤的出现改变了原来的流场并在堤周围形成涡流,造成了堤外冲刷悬浮的泥沙在潮流和涡流作用下向堤内的搬运与沉积;同时波浪场也因防波堤地形的突然变浅波高增加而下蚀海底能量增强.分析认为,防波堤的修建是造成海底冲淤格局重新分布的重要原因.
The change characteristics of erosion/accumulation in the abandoned Huanghe river subaqueous delta was analyzed based on bathymetric survey and profile datum of several years.The studies showed that the dynamic of submarine slope and plain had reached to a quasi-equilibrium state in the abandoned subaqueous delta before breakwater construction,the erosion lower limit of submarine slope stopped at-15 m bathymetric.The submarine slope and plain were eroded after breakwater construction and the erosion lower limit of submarine slope fell to-16.7 m bathymetric.The areas of serious erosion occurred mainly in the afterbody,outer and end of the breakwater,the largest erosion depth was more than 2m.The areas of accumulation occurred mainly in the interior of the breakwater,the accumulation thickness was between 0 and 6m,the net accumulation volume reached to 4.9× 106 m3 and accounted for 65％ of the total accumulation volume.The results of numerical simulation indicated that the remodeled current field because of the construction of breakwater brought the abundant sediment into interior of the breakwater,the outer seabed was eroded again because of the increase of the wave energy brought by sudden change of seabed landform.The analysis found that construction of breakwater was an important factor of the sediment redistribution in the abandoned Huanghe river subaqueous delta.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第6期85-90,共6页
Periodical of Ocean University of China
基金
全球重大基础研究计划项目(2010CB951202)
国家自然科学基金项目(41476069)资助
关键词
废黄河水下三角洲
水深比对
沉积物再分布
数值模拟
防波堤
the abandoned Huanghe river subaqueous delta
bathymetric contrast
the sediment redistribution
numerical simulation
breakwater
