Sedimentary Dynamics and Geomorphic Evolution of the Laizhou Shoal
Sedimentary Dynamics and Geomorphic Evolution of the Laizhou Shoal
复制标题
DOI：
--
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Wang Qing
中科院分区：
文献类型：
--
作者：
Wang Qing
本文在野外调查和历史地貌分析的基础上，以GIS和RS为技术支撑，研究了莱州浅滩自1958年多座水库建成，大量减沙以来的地貌动态特征、演变规律及人为因素对冲淤的影响。结果表明，世纪中期以来，莱州浅滩向北移动，而附近的吊龙嘴则向北移动，这是由于两者之间的地貌动力作用。该浅滩的泥沙直接来自于刁龙嘴海岸，并最终来自于从刁龙嘴嘴到七亩岛的东北向延伸海岸注入渤海的河流。两种主要的沉积动力机制控制着浅滩的冲淤过程。一种是莱州湾西南方向的落潮潮流受到浅滩的阻滞后，转向沿着西北走向的浅滩流动，并在浅滩附近形成由向浅滩流和向浅滩上涌流组成的次级横向环流。因此，在浅滩的西南部发生了侵蚀，在浅滩的顶部发生了沉积，导致浅滩整体向东北方向迁移。另一个原因是浅滩尖端周围潮流的离心作用造成了由底部向浅滩的水流和上部的上升流组成的次级环流。因此，悬沙沉积在浅滩的西北部。
Based on field work and historical geomorphic analysis, and supported by GIS and RS, this paper has researched the geomorphic dynamic characteristics and evolution rules and the artificial effects on erosion and deposition of the Laizhou shoal since 1958, when many reservoirs were built, and a great amount of sand began to be reduced. The results show that the Laizhou shoal has been moving northward while the nearby Diaolongzui spit moving northward because of the geomorphic-dynamics between them since the mid-19th century. The sand made up of the shoal has come directly from the Diaolongzui coast, and ultimately from the rivers which empties into the Bohai Sea across the NE direction stretching coast from the Diaolongzui spit to the Qimudao island. There are two main depositional dynamic mechanisms, which have been controlling the shoal erosion and deposition processes. One is that when the ebb tidal current from the south-west Laizhou bay is retarded by the shoal, it turns to flow along the west-northern striking shoal with a secondary transverse circulation made up of shoalward currents in the bottom and upwelling currents near the shoal. So, erosion took place on the SW part, and deposition on the top part of the shoal, which led to the shoal migrating toward NE as a whole. Another is that the centrifugal effect of tidal currents around the pointed end of the shoal causes a secondary circulation made up of shoalward currents in the bottom and upwelling currents in the upper. So, the suspended sand deposits on the NW part of the shoal.