风暴过程中潮滩悬沙浓度和悬沙输运的变化及其动力机制——以长江三角洲南汇潮滩为例

苗丽敏; 杨世伦; 朱琴; 史本伟; 李鹏; 吴创收

doi:10.3969/j.issn.0253-4193.2016.05.015

风暴过程中潮滩悬沙浓度和悬沙输运的变化及其动力机制——以长江三角洲南汇潮滩为例

doi: 10.3969/j.issn.0253-4193.2016.05.015

1.
华东师范大学河口海岸学国家重点实验室, 上海 200062
2.
南京大学地理与海洋科学学院, 江苏南京 210093
3.
国家海洋局东海预报中心, 上海 200136
4.
浙江省水利河口研究院, 浙江杭州 310020

基金项目: 国家自然科学基金项目(41576092,41130856)。

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出版历程
- 收稿日期: 2015-07-28

Variations of suspended sediment concentrations and transport in response to a storm and its dynamic mechanism——A study case of Nanhui tidal flat of the Yangtze River Delta

1.
State Key Laboratory of Estuarine and Costal Research, East China Normal University, Shanghai 200062, China
2.
Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China
3.
Forecasting Centers of East China Sea, State Oceanic Administration, Shanghai 200136, China
4.
Zhejiang Institute of Hydraulics and Estuary, Hangzhou 310020, China

摘要

摘要: 悬沙浓度是淤泥质海岸重要的环境指标。为探讨潮滩悬沙浓度和悬沙输运对风暴事件的响应过程及其动力机制,于2014年9月"凤凰"台风过境前、中、后在长江三角洲南汇潮滩进行了现场观测,获得同步高分辨率的水深、波高、近底流速和浊度剖面时间序列(9个潮周期)。结果表明,风暴中平均和最大波高、波-流联合底床剪切应力、悬沙浓度和悬沙输运率可比平静天气高数倍;风暴期间高潮位低流速阶段悬沙沉降导致近底发育数十厘米厚的浮泥层(悬沙浓度大于10 g/L)。研究认为风暴事件中淤泥质海岸悬沙浓度和悬沙输运的剧烈变化其根本动力机制是风暴把巨大能量传递给近岸水体,进而显著增大波-流联合底床剪切应力,导致细颗粒泥沙再悬浮。
- 风暴 /
- 潮滩 /
- 悬沙浓度 /
- 悬沙输运 /
- 波-流联合剪切应力 /
- 浮泥 /
- 长江三角洲
Abstract: Suspended sediment concentration (SSC) is an important environmental index of muddy coasts. To understand the response of the suspended sediment concentration and suspended sediment transport on tidal flat to a certain storm event, we carried out in situ measurements of water depth, wave height, near-bed velocity and SSC profiles in high resolution on an intertidal mudflat of Nanhui Spit, which is on the delta front of the Yangtze River, China. The measurements last for 9 tidal cycles, covering pre-, intra-and post-"Fung-wong" typhoon. The results show that: (1) mean and max wave heights, bed shear stress , SSC and suspended sediment transport rate during storm condition were several times higher than those in calm weather; (2) in storm condition, a fluid mud layer (SSC>10 g/L) in the thickness of tens of centimeters developed during slack water at high tides, resulting from settling of suspended sediment. We conclude that the drastic variation of suspended sediment concentration in muddy coastal areas is caused by enhanced energy in the water column caused by storm, leading to increasing combined wave-current bed shear stress, which leads to bed sediment resuspension.
- storm /
- tidal flat /
- suspended sediment concentration /
- suspended sediment transport /
- bed shear stress under combined wave-current action /
- fluid mud /
- Yangtze River Delta

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参考文献(36)

Gao S. Geomorphology and sedimentology of tidal flats[M]//Coastal Wetlands: An Ecosystem Integrated Approach. Amsterdam:Elsevier, 2009: 295-316.

Wang Y, Gao S, Jia J. High-resolution data collection for analysis of sediment dynamic processes associated with combined current-wave action over intertidal flats[J]. Chinese Science Bulletin, 2006, 51(7): 866-877.

杨世伦, 谢文辉. 大河口潮滩地貌动力过程的研究—以长江口为例[J]. 地理学与国土研究, 2001, 17(3): 44-48. Yang Shilun, Xie Wenhui. A study of intertidal flat morphodynamics of a large river mouth: Yangtze River mouth[J]. Geography and Territorial Research, 2001, 17(3): 44-48.

Hooke J M, Bray M J, Carter D J. Sediment transport analysis as a component of coastal management—a UK example[J]. Environmental Geology, 1996, 27(4): 347-357.

Van Steeter M M, Pitlick J. Geomorphology and endangered fish habitats of the upper Colorado River 1. Historic changes in streamflow, sediment load, and channel morphology[J]. Water Resources Research, 1998, 34(2): 287-302.

Zheng L, Chen C, Zhang F Y. Development of water quality model in the Satilla River Estuary, Georgia[J]. Ecological modelling, 2004, 178(3): 457-482.

Gao P, Pasternack G B, Bali K M, et al. Suspended-sediment transport in an intensively cultivated watershed in southeastern California[J]. Catena, 2007, 69(3): 239-252.

Lindsay P, Balls P W, West J R. Influence of tidal range and river discharge on suspended particulate matter fluxes in the Forth Estuary (Scotland)[J]. Estuarine, Coastal and Shelf Science, 1996, 42(1): 63-82.

Schoellhamer D H, Mumley T E, Leatherbarrow J E. Suspended sediment and sediment-associated contaminants in San Francisco Bay[J]. Environmental Research, 2007, 105(1): 119-131.

Van de Kreeke J, Day C M, Mulder H P J. Tidal variations in suspended sediment concentration in the Ems estuary: origin and resulting sediment flux[J]. Journal of Sea Research, 1997, 38(1): 1-16.

Tattersall G R, Elliott A J, Lynn N M. Suspended sediment concentrations in the Tamar estuary[J]. Estuarine, Coastal and Shelf Science, 2003, 57(4): 679-688.

Uncles R J, Stephens J A. Turbidity and sediment transport in a muddy sub-estuary[J]. Estuarine, Coastal and Shelf Science, 2010, 87(2): 213-224.

Bassoullet P, Le Hir P, Gouleau D, et al. Sediment transport over an intertidal mudflat: field investigations and estimation of fluxes within the "Baie de Marenngres-Oleron"(France)[J]. Continental Shelf Research, 2000, 20(12): 1635-1653.

Li P, Yang S L, Milliman J D, et al. Spatial, temporal, and human-induced variations in suspended sediment concentration in the surface waters of the Yangtze Estuary and adjacent coastal areas[J]. Estuaries and Coasts, 2012, 35(5): 1316-1327.

Liu J H, Yang S L, Zhu Q, et al. Controls on suspended sediment concentration profiles in the shallow and turbid Yangtze Estuary[J]. Continental Shelf Research, 2014, 90: 96-108.

Schoellhamer D H. Anthropogenic sediment resuspension mechanisms in a shallow microtidal estuary[J]. Estuarine, Coastal and Shelf Science, 1996, 43(5): 533-548.

Dyer K R, Christie M C, Feates N, et al. An investigation into processes influencing the morphodynamics of an intertidal mudflat, the Dollard Estuary, the Netherlands: I. Hydrodynamics and suspended sediment[J]. Estuarine, Coastal and Shelf Science, 2000, 50(5): 607-625.

Quaresma V S, Bastos A C, Amos C L. Sedimentary processes over an intertidal flat: A field investigation at Hythe flats, Southampton Water (UK)[J]. Marine geology, 2007, 241(1): 117-136.

Yang S L, Li P, Gao A, et al. Cyclical variability of suspended sediment concentration over a low-energy tidal flat in Jiaozhou Bay, China: effect of shoaling on wave impact[J]. Geo-Marine Letters, 2007, 27(5): 345-353.

Wang Y P, Gao S, Jia J, et al. Sediment transport over an accretional intertidal flat with influences of reclamation, Jiangsu coast, China[J]. Marine Geology, 2012, 291: 147-161.

Shi B W, Yang S L, Wang Y P, et al. Intratidal erosion and deposition rates inferred from field observations of hydrodynamic and sedimentary processes: A case study of a mudflat-saltmarsh transition at the Yangtze delta front[J]. Continental Shelf Research, 2014, 90: 109-116.

Zhu Q, Yang S, Ma Y. Intra-tidal sedimentary processes associated with combined wave-current action on an exposed, erosional mudflat, southeastern Yangtze River Delta, China[J]. Marine Geology, 2014, 347: 95-106.

Wang A J, Gao S, Chen J, et al. Sediment dynamic responses of coastal salt marsh to typhoon "KAEMI" in Quanzhou Bay, Fujian Province, China[J]. Chinese Science Bulletin, 2009, 54(1): 120-130.

Turner R E, Baustian J J, Swenson E M, et al. Wetland sedimentation from hurricanes Katrina and Rita[J]. Science, 2006, 314(5798): 449-452.

陈沈良. 杭州湾口南汇咀近岸水域水沙特征与通量[J]. 海洋科学, 2004, 28(3): 18-22. Chen Shenliang. Hydrological and sediment features and fluxes in Nanhui nearshore waters, Hangzhou Bay[J]. Marine Sciences, 2004, 28(3): 18-22.

Yang S L, Li H, Ysebaert T, et al. Spatial and temporal variations in sediment grain size in tidal wetlands, Yangtze Delta: on the role of physical and biotic controls[J]. Estuarine, Coastal and Shelf Science, 2008, 77(4): 657-671.

Yang S L, Li M, Dai S B, et al. Drastic decrease in sediment supply from the Yangtze River and its challenge to coastal wetland management[J]. Geophysical Research Letters, 2006, 33(6): 1-4.

Soulsby R L, Clarke S. Bed shear-stresses under combined waves and currents on smooth and rough beds[J]. HR Wallingford, Report TR137, 2005.

De Swart H E, Zimmerman J T F. Morphodynamics of tidal inlet systems[J]. Annual Review of Fluid Mechanics, 2009, 41(1): 203-229.

Van Rijn L C. Principles of sediment transport in rivers, estuaries and coastal seas[M]. Amsterdam: Aqua Publications, 1993.

Soulsby R L, Clarke S. Bed shear-stresses under combined waves and currents on smooth and rough beds[J]. HR Wallingford, Report TR137, 2005.

Taki K. Critical shear stress for cohesive sediment transport[J]. Proceedings in Marine Science, 2000, 3: 53-61.

Yang S L, Friedrichs C T, Shi Z, et al. Morphological response of tidal marshes, flats and channels of the outer Yangtze River mouth to a major storm[J]. Estuaries, 2003, 26(6): 1416-1425.

Xu K, Mickey R C, Chen Q, et al. Shelf sediment transport during hurricanes Katrina and Rita[J]. Computers & Geosciences, 2016,90(B): 24-39.

徐福敏, 张长宽. 台风浪对长江口深水航道骤淤的影响研究[J]. 水动力学研究与进展: A 辑, 2004, 19(2): 137-143. Xu Fumin, Zhang Changkuan. Study of the effect of storm waves on the rapid deposition of the Yangtze River Estuary channel[J]. Journal of Hydrodynamics, Ser A , 2004, 19(2): 137-143.

Stumpf R P. The process of sedimentation on the surface of a salt marsh[J]. Estuarine, Coastal and Shelf Science, 1983, 17(5): 495-508.

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