秦皇岛金梦湾海滩侵蚀和海滩养护

金梦湾海滩是秦皇岛海港区西部较大的浴场,地理位置优越,但在养滩工程前曾遭受着严重的侵蚀,侵蚀速率在1.26~1.98 m/a之间,最大可达3.86 m/a,海滩宽度为40~90 m,沉积物粗化严重,海滩质量较差,严重影响了海滩的旅游功能。海滩修复工程主要采用近岸补沙和建设生态离岸潜堤的方式,其中近岸补沙方量为172.5×104 m3,离岸潜堤3条。工程后经过1年多的观测,海滩仅在工程后初期侵蚀量较大,之后海滩侵蚀趋势明显减弱,海滩逐渐向平衡状态发展。养滩15个月后,海滩上仍保留了83.4%的沙体,养滩效果良好。

BEACH EROSION AND BEACH NOURISHMENT OF JINMENG BAY BEACH IN QINHUANGDAO

The Jinmeng Bay is a large bathing beach in western Qinhuangdao. The width of the beach was about 40-90 m. It had been under severe erosion before nourishment at an average erosion rate of 1.26-1.98 m/a. The biggest erosion rate might be as high as 3.86 m/a. The increase in coarse sediments of poor quality had seriously affected the beach tourism. The restoration work included nourishment of 172.5×104 m3 sand in the near shore area and construction of 3 offshore submerged-dikes. After more than one year of monitoring after the nourishment, we found that a large amount of filling sand was eroded immediately after the beach nourishment. Then the beach erosion was reducing and gradually the beach reached a status of balance. After fifteen months, there remained 83.4% of the nourished sand. It is regarded as a successful case of beach nourishment.