厦门大嶝海域现代沉积过程及其对高强度人类活动的响应  

Sedimentary processes and its response to intensive human activities in area near Dadeng Island,Xiamen

作　　者：叶翔[1] 章文琼 王爱军[1] 

机构地区：[1]国家海洋局第三海洋研究所海洋与海岸地质实验室,福建厦门361005

出　　处：《应用海洋学学报》2015年第4期559-567,共9页Journal of Applied Oceanography

基　　金：海洋公益性行业科研专项资助项目(201405025);国家自然科学基金资助项目(41076035;41206048;41376070)

摘　　要：沉积物粒度是反应区域自然环境和人类活动变化的敏感参数之一.粒度分析结果表明,厦门大嶝海域表层沉积物以粘土质粉砂为主,其次为粉砂质砂;中值粒径范围为-0.16~7.17φ.^(210)Pb年代学分析结果显示,大嶝岛西南侧靠近五沙水道附近浅海区平均沉积速率最小(仅为0.36 cm/a),大嶝岛西南侧近岸潮间带平均沉积速率最高(可达3.94 cm/a),大嶝岛南侧近岸和北侧大嶝水道顶端海域平均沉积速率分别为1.26、1.14 cm/a.大嶝海域现代沉积过程主要受沉积动力过程和高强度人类活动控制.在潮流输沙的作用下,大量悬沙在大嶝岛西南侧海域沉积从而导致该海域沉积速率最高,而大嶝岛东侧近岸由于海底经常发生侵蚀,故沉积速率较低(仅为0.58 cm/a).近年来的高强度围填海活动及海堤建造等都明显加速了大嶝海域的沉积过程,其中因人类活动导致大嶝岛西南侧浅滩地区的沉积速率提高了4倍;围填海活动导致大量泥沙入海,对大嶝岛与小嶝岛之间海域的现代沉积过程产生重要影响.Sediment grain size is a sensitive parameter for the variations of regional physical environmental and hu- man activities. Analysis of sediment grain size show that the sediment is dominated by clayey silt in area near Da- deng Island, Xiamen Bay. The sediment median grain size ranges from -0. 16 φ to 7.17 φ. The results of 210Pb dating indicate that the minimum sedimentation rate occurs at the southwest area near the Xiamen-Jinmen Channel with a mean value of 0.36 cm/a, and maximum rate occurs at the shoal area at the southwest of Dadeng Island with a mean value of 3.94 cm/a. The mediate sedimentation rates occur at the south and north area near Dadeng Island with mean values of 1.26 cm/a and 1.14 cm/a, respectively. The modern sedimentary processes near Dadeng Is- land are controlled by 2 factors, i. e. , sediment dynamic process and high intensive human activities. Under the influence of suspended sediment transport induced by tidal current, amount of suspended sediment settles to the seabed at the shoal area, southwest of Dadeng Island, which leads to the highest sedimentation rate. However, be- cause of the frequent seabed erosion at the east area near Dadeng Island, the sedimentation rate is very low （0.58 cm/a）. In recent years, high intensive human activities, such as reclamation and sea wall constructions, intensify the settling processes. The sedimentation rate since 1995 is 4 times higher than the time before 1995 due to inten- sive reclamation and the construction of Dadeng Sea Wall. Moreover, amount of sediment enters to the coastal area, induced by the reclamation at the east of Dadeng Island, which should have major impact on the modern sedimenta- ry processes in areas between Dadeng Island and Xiaodeng Island.

关 键 词：海洋地质学 沉积过程 沉积速率 高强度人类活动 围填海 大嶝岛 

分 类 号：P736[天文地球—海洋地质]