| 摘要: |
| 为研究潮间带和潮下带的水、沙、盐交换，于2006年6月25~28日（夏季大潮）和2006年12月29日~2007年1月4日（冬季中-大潮和小潮）在长江口九段沙一典型潮沟的固定点利用OBS-3A和ADP-XR进行了水深、浊度、盐度、流速流向剖面和回声强度观测。结果和结论为：（1）夏季大潮、冬季中-大潮、冬季小潮的潮周期垂向平均流速分别为26.5、15.9和8.4 cm/s，夏、冬季观测到的最大流速分别为84 cm/s和35 cm/s。（2）夏季盐度变化范围为0.65~4.91，平均盐度2.14；冬季盐度变化范围为3.5~10.3，中-大潮和小潮平均盐度分别为6.26和7.98。（3）高悬沙浓度出现在涨潮初期和部分落潮末期的低水位阶段；涨潮阶段的平均悬沙浓度是落潮阶段的1.11~7.0倍。（4）涨、落潮阶段的水体和盐输运量大体上趋于平衡；（5）无论是冬夏季或大小潮，潮沟在潮周期内的净输沙方向均指向陆，即落潮输沙量小于涨潮输沙量（平均小40%）；平均每个潮周期的净输沙量为6102 kg，结合潮盆面积推算的潮周期沉积速率为0.0112 mm/tide，或8.2 mm/a。 |
| 关键词: 长江口，九段沙，潮沟，滩地发育，物质交换 |
| DOI：10.11693/hyhz20121010001 |
| 分类号: |
| 基金项目:国家自然科学基金项目（41071014）、科技部全球变化项目课题（2010CB951202,）、上海市科委课题（10dz1210505）河口海岸学国家重点实验室自主课题（SKLEC-2012KYYW06） |
附件 |
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| Interchange processes of water, sediment and salinity over an intertidal flat based on fixed observation in a tidal channel |
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Li Peng and Yang Shilun
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East China Sea Forecast Centre, SOA, Shanghai,State Key Lab of Estuarine and Coastal Research, East China Normal University
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| Abstract: |
| To research the interchange processes of water, sediment and salinity in the tidal flat of Jiuduansha Island, water depth, Turbidity, salinity, vertical current speed and direction and echo intensity were observed using OBS-3A and ADP-XR in summer spring tide and winter middle-spring and neap tide, in a fixed site of a tidal channel in Jiuduansha Island. The results show: (1) Vertical average current speed in winter middle-spring and neap tide were 15.9 and 8.4 cm/s, respectively, while in summer the current speed reached 26.5 cm/s. The biggest speed during observation in summer and winter were 84 and 35 cm/s. (2) Salinity was higher in winter than in summer, with the range of 0.65~4.91 in summer (2.14 in average) and 3.5~10.28 in winter (6.28 and 7.98 in middle-spring and neap tide in average). (3) High SSC occurred during the shallow water stage at the beginning and the end of inundation. The average SSC was higher in flood period than in ebb period. The average SSC became higher was from surface to bottom gradually. (4)The discharge of water and salinity in-out the tidal basin were basic balance, while about 40% of sediment discharge transported during flood tidal period was detained in the tidal basin. The average sediment discharge carried during every tide was 6102kg, and the accretion rate was 0.0112mm/tide. The results show that the tidal basin was in accretion with the accretion rate of 8.2mm/year. |
| Key words: Yangtze estuary, Jiuduansha, tidal channel, evolution of tidal flat, interchange of water and sediment |
