| 摘要: |
| 潮滩是陆海交互影响的重要区域，在陆海物质交换的过程中扮演着重要的角色。象山港位于浙江宁波，是典型的半封闭式港湾，受人类活动影响显著。本文取其重要支港西沪港为研究区，自其潮上带至潮间带采集表层沉积样品，进行总有机碳（Total Organic Carbon，TOC）、总氮（Total Nitrogen，TN）和稳定碳同位素δ13C等测试。分析象山港潮滩有机质分布的空间特征，并估算陆源有机质的贡献率的空间差异，探讨了影响象山港潮滩有机质的物源因素。结果显示：（1）潮滩表层沉积物TOC均值为0.86%，δ13C均值为-23.58‰。在平均海面附近的样品TOC和δ13C均出现异常值，其中TOC约2.3%，而δ13C约-26.44‰，指示有大量陆源有机质在平均海面附近累积。（2）δ13C总体上随高程下降而下降，潮上带平均值为-22.40‰，潮间带平均值为-23.33‰。（3）有机质累积受植被、养殖、污水排放等影响。潮上带和高潮滩表层沉积物受潮滩植被影响显著；平均海面附近样品的δ13C与生活污水和沿岸围塘养殖的δ13C接近，说明象山港潮动力较弱，沿岸人类活动产生的有机质容易在平均海面附近大量累积。 |
| 关键词: 潮滩 半封闭港湾 有机质 物源 |
| DOI：10.11693/hyhz20200400120 |
| 分类号:K903 |
| 基金项目:NSFC-浙江两化融合联合基金，U1609203号；国家自然科学基金，41976209号；浙江省自然科学基金，LQ15D020001号；浙江省省属高校基本科研业务费专项资金资助，SJLY2020004号。 |
附件 |
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| SOURCE AND DISTRIBUTION OF ORGANIC MATTERS IN TIDAL FLAT OF XIANGSHAN BAY |
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XU Hao1,2, FENG Bai-Xiang2,3, LI Jia-Lin1,2, HE Gai-Li2,4
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1.Institute of East China Sea, Ningbo University, Ningbo 315211, China;2.Department of Geography and Spatial Information Techniques, Ningbo University, Ningbo 315211, China;3.Institute of Ningbo development planning, Ningbo 315042, China;4.School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China
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| Abstract: |
| Tidal flat is an important area of land-sea interaction, which plays an important role in the process of land-sea material exchange. Xiangshan Bay is a semi-closed bay located in Ningbo, Zhejiang Province. The bay is heavily influenced by human activities. As an important tributary bay of Xiangshan Bay, Xihu Bay was selected as the research area. Surface sedimentary samples were collected from supratidal zone to intertidal zone. Based on the test of TOC, TN, and δ13C, the distribution of organic matters was revealed and the contribution of terrigenous organic matter was estimated. Furthermore, the influence of sources of organic matters were discussed. Results indicate that the mean value of TOC was 0.86%, and the mean value of δ13C was -23.58‰. However, the TOC and δ13C of the samples near the mean sea level showed abnormal values, of which TOC was about 2.3%, while δ13C was about -26.44‰, indicating that a large amount of terrigenous organic matter accumulated near the average sea surface. In addition, δ13C decreased with the altitude descent. The mean value δ13C in supratidal zone was about -22.40‰, the mean value δ13C in intertidal zone was about -23.33‰. Moreover, the sources of organic maters were related to vegetation, aquaculture, sewage discharge, and so on. The sediment in the supratidal zone was influenced by salt-water cordgrass Spartina alterniflora, and the sediments nearby sea level were affected obviously by aquaculture and sewage discharge. It shows that the tidal power of Xiangshan Bay is weak, and the organic matter produced by human activities along the coast is easy to accumulate near the average sea level. |
| Key words: tidal flat semi-closed bay organic matter provenance |
