文登近岸海域沉积物运移及控制因素研究

发布时间：2019-05-19 07:16

【摘要】：文登市位于山东半岛东南部，近岸海域拥有优质的天然沙滩和海水浴场。本文利用近期调查资料对文登近岸海域的沉积物、水文动力、泥沙运移和冲淤特征进行研究，研究成果对于近岸海域泥沙运移规律的认识和海滩的养护等方面具有一定意义。本文根据2013年7月采集到的173个表层沉积物样品和95个碎屑矿物样品，分析研究了表层沉积物类型、粒度特征和矿物分布规律；利用数值模拟方法，模拟了研究区潮流场、波浪场和冲淤现状特征；通过窦国仁、Sunamura、佐藤、美国海岸工程研究中心等数学公式，计算分析了研究区表层沉积物的起动流速、泥沙活动水深、沿岸输沙等内容；利用1980年和2013年2期水深地形资料，研究了水深地形变化规律；利用2005年和2013年2期卫星遥感影像资料，对比分析了研究区岸线变化特征。在此基础上，研究了文登近岸海域表层沉积物的运移特征，并探讨了控制沉积物运移的因素，研究结果表明：（1）文登近岸海域沉积物类型主要包括粉砂和粘土质粉砂。整体上，沉积物粒径由岸向海逐渐变细，分选变差。碎屑矿物分析鉴定出重矿物35种，轻矿物14种。重矿物中，黑云母等片状矿物受水动力的影响显著，表现出由岸向海含量逐渐增高的特点；轻矿物中，斜长石等主要轻矿物含量等值线分布方向与偏S向的波浪方向一致，这是波浪对碎屑矿物搬运的结果。（2）研究区大潮期，涨急时刻潮流整体上由东往西流，落急时潮流整体由西向东流；研究区波浪场受张家埠新港的影响，波浪作用减弱，并在防波堤附近形成波影区；研究区周边海域整体以微淤积为主，绝大部分区域的年淤积量小于2cm；侵蚀区主要位于张家埠新港防波堤堤头，年最大侵蚀量约16cm。（3）研究区海域沉积物的整体运移趋势为：沿岸（羊村口至小里岛）表层沉积物输运趋势是由西南向东北，在泽库半岛西侧是由南向北，张家埠新港南侧是由东南向西北，表层沉积物整体上向五垒岛湾汇聚，从而塑造了湾内的潮滩地貌，导致了五垒岛湾的淤积现状。（4）研究区内表层沉积物在单纯潮流的作用下基本不能起动，当波浪作用搅动海底表层沉积物后，潮流对泥沙的输运起了主导作用，“波浪掀沙，潮流输沙”控制了研究区沉积物的运移与分布，，形成了研究区中部颗粒较粗，东西两侧颗粒较细的沉积物分布规律。（5）张家埠新港的建设是影响研究区沉积物运移的主要的人为因素。新港建设后向海延伸约5km，阻挡了研究区偏E向的波浪，在研究区东部形成波影区，在码头和引堤处最大流速变化达60cm/s，泽库半岛西侧净输沙量增加了52.7×104m3/a。新港的建设直接改变了原有的岸线，影响了水动力条件和沉积环境，从而影响沉积物的运移。
[Abstract]:Wendeng City is located in the southeast of Shandong Peninsula, coastal waters with high-quality natural beaches and sea baths. In this paper, the sediment, hydrological dynamics, sediment transport and scouring and silting characteristics of Wendeng inshore sea area are studied by using the recent survey data. The research results are of certain significance for the understanding of sediment transport law and beach maintenance in the coastal area. Based on 173 surface sediment samples and 95 clastic mineral samples collected in July 2013, the types, grain size characteristics and mineral distribution of surface sediments were analyzed and studied in this paper. The characteristics of tidal flow field, wave field and scouring and silting in the study area are simulated by numerical simulation method. Based on the mathematical formulas of Dou Guoren, Sunamura, Sato and the United States Coastal Engineering Research Center, the starting velocity, sediment active water depth and coastal sediment transport of the surface sediments in the study area are calculated and analyzed. Based on the water depth topographic data of 1980 and 2013, the variation law of water depth topography is studied, and the shoreline variation characteristics of the study area are compared and analyzed by using the satellite remote sensing image data of 2005 and 2013. On this basis, the transport characteristics of surface sediments in Wendeng coastal waters are studied, and the factors controlling sediment transport are discussed. The results show that: (1) the sediment types in Wendeng coastal area mainly include silt and clay silt. On the whole, the particle size of sediment gradually becomes fine from shore to sea, and the separation becomes worse. 35 species of heavy minerals and 14 species of light minerals were identified by clastic mineral analysis. Among the heavy minerals, biotite and other flake minerals are significantly affected by hydrodynamic force, which shows that the content of biotite and other flake minerals increases gradually from shore to sea. In the light minerals, the distribution direction of the contours of the main light minerals, such as plagioclase, is consistent with the wave direction of the partial S direction, which is the result of the wave transport to the clastic minerals. (2) during the tidal period of the study area, the tidal current flows from east to west as a whole and from west to east when the tidal current falls, and the wave field in the study area is affected by Zhangjiabu Xingang, the wave action is weakened, and the wave shadow area is formed near the breakwater. The whole surrounding sea area of the study area is mainly micro-siltation, the annual siltation in most areas is less than 2 cm, and the erosion area is mainly located at the head of Zhangjiabu Xingang breakwater, with an annual maximum erosion of about 16 cm. (3) the overall migration trend of sediments in the study area is as follows: the transport trend of surface sediments along the coast (Yangcukou to Xiaoli Island) is from southwest to northeast, from south to north on the west side of Zecu Peninsula, and from southeast to northwest on the south side of Zhangjiabu Xingang. The surface sediments converge to Wuyi Island Bay as a whole, thus shaping the tidal flat landform in the Bay, which leads to the siltation status of Wuyi Island Bay. (4) the surface sediments in the study area can not start under the action of simple tidal current. When the wave acts to stir the surface sediments of the seafloor, the tidal current plays a leading role in sediment transportation. Tidal current sediment transport controls the migration and distribution of sediments in the study area, and forms the distribution law of sediments with coarse particles in the middle of the study area and fine particles on both sides of the east and west sides of the study area. (5) the construction of Zhangjiabu Xingang is the main human factor affecting sediment transport in the study area. After the construction of Xingang, it extends to the sea about 5 km, which blocks the waves in E direction of the study area. The wave shadow area is formed in the eastern part of the study area. The maximum velocity variation at the wharf and levee is 60 cm / s, and the net sediment transport on the west side of Zecu Peninsula increases by 52.7 脳 10 ~ 4 m ~ 3 / a. The construction of Xingang has directly changed the original shoreline, affected the hydrodynamic conditions and sedimentary environment, and thus affected the transport of sediments.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P736.21

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