海南岛南渡江三角洲的废弃与侵蚀  

Erosion and abandonment of the Nandu River Delta, Hainan Island

作　　者：罗宪林[1] 李春初[1] 罗章仁[1] 

机构地区：[1]中山大学河口海岸研究所,广州510275

出　　处：《海洋学报》2000年第3期55-60,共6页

基　　金：国家自然科学基金!49271015;49171009

摘　　要：讨论了海南岛南渡江三角洲由发展到废弃的演化过程，分析了不同废弃阶段的河口平面形态由东向西变化等特征，对比活动三角洲与废弃三角洲的显著地貌差异．此外还讨论了活动三角洲前缘潮流在岸外较深水区的侵蚀作用和泥沙的向东搬运，以及波浪在近岸较浅水区的侵蚀作用和泥沙的向西和向岸的搬运．While the area of the Nandu River Delta in Hainan Island of China is only 120 km^2, the abandoned part accounts for 80 km^2. According to carbon-14 dating data, stratigraphic factes, and old barrier island analysis results, it is shown that the Nandu River Delta developed from the south to the north toward the Qiongzhou Strait during the period of 4 000 --8 000 a BP, and that it developed from the east to the west toward the Haikou Bay during the period of 2 000-- 4 000 a BP. The deposit center of the delta was diverted toward the Haikou Bay, and the eastern part of the delta was abandoned due to the operation of the prevailing northeast wave. The geomorphic characteristics of the abandoned delta: linear transgressive shore, marsh mud on the beach face, a set of abandoned, semi- a-bandoned and active river mouths displayed from the east to the west, etc., are present. Erosion is very obvious in the active delta front. The erosive rate of the shoreline is about 8 -- 10 m/a. The linear scarp along 10 m depth curve was cut by the strait tidal current and the sediment was transported to the east. The northeastern part of the subaquatic delta of the Nandu River mouth was cut by the northeast wave and the sediment was transported to the west and shoreward.

关 键 词：废弃三角洲 海岸侵蚀 海南岛 南渡江 三角洲 

分 类 号：P737.121[天文地球—海洋地质] P737.1[天文地球—海洋科学]