海阳砂质海岸岸滩演化
EVOLUTION OF THE SANDY BEACH IN HAIYANG
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摘要: 基于海阳近岸海域的水深地形、表层沉积物粒度以及遥感影像等资料,利用泥沙起动流速和沿岸输沙数理公式以及岸滩演化数学模型,探讨了海阳近岸海域岸滩演化特征及主要控制因素。研究结果表明,研究区总体处于动态平衡状态,潮流很难使泥沙发生直接起动,波浪造成的沿岸输沙总体向ENE方向运移。影响研究区冲淤变化的因素主要有河流来沙、波浪以及人工构筑物。河流径流量减小,导致研究区泥沙来源减少,加剧了局部海岸侵蚀;近岸人工构筑物的建设,改变了泥沙输运趋势,并导致局部冲淤环境发生变化;波浪是控制研究区泥沙运移、沉降的关键因素,控制着研究区冲淤演化的整体格局。Abstract: This paper discusses the evolution of the beach and its controlling factors in the nearshore area of Haiyang, using several methods including calculation of the incipient velocity of the sediment, mathematical approaches for coastal transportation of sediment, and mathematical modeling for beach evolution, based on the depth and grain size data and remote images. The results show that the beach of the study area is roughly in a state of dynamic equilibrium as a whole. It is difficult for the sediment to make incipient motion. Longshore transport caused by waves may move the sediment to ENE direction. Factors affecting the changes of erosion and deposition include sand supply from rivers, waves and artificial structures. The reduction of rivers runoff may cause the decrease in sediment input and increase the erosion of local coast. The construction of coastal artificial structures may change the migration path of sediment, and lead to the local changes in erosional and depositional patterns. Wave is a key factor in controlling sediment transportation and sedimentation. In conclusion, hydrodynamics is the factor controlling the overall evolutional pattern of erosion or deposition in the study area.