广东湛江外罗海域水沙环境及岸滩演变
WATER AND SEDIMENTS BUDGET AND BEACH EVOLVEMENT OF THE AREA NEAR WAILUO OF ZHANJIANG, GUANGDONG PROVINCE
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摘要: 依据不同时期地形资料,对广东湛江外罗海域海床的岸滩冲淤变化进行了分析,并结合水文泥沙资料探讨了冲淤变化原因和发展趋势,结果显示:①多年来整个研究海域地形有冲有淤,总体上冲刷范围大于淤积范围; ②从2个时期(40年长期和6年短期)该海域冲刷来看,在自然状态下,经过长期的冲刷和恢复作用,研究海域最大冲刷深度应该在5.0 m左右; ③强风和台风引起的波浪对海岸和海底侵蚀、堆积影响很大,是地形塑造的主要因素,正常天气下的风浪流起到一个地形恢复的作用,但往往难以恢复到原来的状态,造成一定的冲刷和堆积;④在现有动力泥沙环境没有大的变化的情况下,这种中长期尺度的最大冲刷趋势仍将延续该发展趋势。Abstract: The coastal and beach erosion and deposition pattern of the Wailuo Sea Area of Zhanjiang is analyzed based on the three topographical maps of 1969,2006 and 2012, and field observations of sediment dynamics. The results show that:(1) in the study area, scouring has dominated deposition for years; (2) Induced from the records of the two periods of 40 years and 6 years, the maximum scour depth is around 5.0 m in the study area; (3) waves caused by typhoons and strong winds had a great influence on the coast and seabed erosion and accumulation. It is the main factor of terrain shaping, and winds and flows under normal weather play the role of terrain recovery; (4) if the existing dynamic pattern does not change much, the long-term scour trends will remain unchanged.