The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats
Periods of very shallow water (water depth in the order of 10 cm) occur daily on tidal flats because of the propagation of tides over very gently sloping beds, leading to distinct morphodynamical phenomena. To improve the understanding of the characteristics of velocity and suspended sediment concen...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-03-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2021.599799/full |
| _version_ | 1818951335791296512 |
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| author | Qian Zhang Zheng Gong Zheng Gong Changkuan Zhang Jessica Lacy Bruce Jaffe Beibei Xu Xindi Chen |
| author_facet | Qian Zhang Zheng Gong Zheng Gong Changkuan Zhang Jessica Lacy Bruce Jaffe Beibei Xu Xindi Chen |
| author_sort | Qian Zhang |
| collection | DOAJ |
| description | Periods of very shallow water (water depth in the order of 10 cm) occur daily on tidal flats because of the propagation of tides over very gently sloping beds, leading to distinct morphodynamical phenomena. To improve the understanding of the characteristics of velocity and suspended sediment concentration (SSC) surges and their contribution to sediment transport and local bed changes during periods of very shallow water, measurements of near-bed flow, and SSC were carried out at two cross-shore locations on an intertidal flat along the Jiangsu coast, China. Furthermore, the role of surges in local resuspension and morphological change was explored. Results indicate that flow and SSC surges occurred at both stations during very shallow water periods. On the lower intertidal flat, flood surges were erosive, while weaker surges on the middle intertidal flat were not. Surges on lower intertidal flats resulted in local resuspension and strong turbidity, contributing up to 25% of the onshore-suspended sediment flux during flood tides, even though they last only 10% of the flood duration. When surges travel across the flats, conditions change from erosional to depositional. Velocity surges on the middle intertidal flat were too weak to resuspend bed sediment, and the associated SSC surges were produced by advection. |
| first_indexed | 2024-12-20T09:32:51Z |
| format | Article |
| id | doaj.art-e8f6b24fe8b441c3959433c9540a0142 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-12-20T09:32:51Z |
| publishDate | 2021-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-e8f6b24fe8b441c3959433c9540a01422022-12-21T19:45:04ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452021-03-01810.3389/fmars.2021.599799599799The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal FlatsQian Zhang0Zheng Gong1Zheng Gong2Changkuan Zhang3Jessica Lacy4Bruce Jaffe5Beibei Xu6Xindi Chen7Jiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security, Hohai University, Nanjing, ChinaJiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security, Hohai University, Nanjing, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, ChinaJiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security, Hohai University, Nanjing, ChinaU.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA, United StatesU.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA, United StatesJiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security, Hohai University, Nanjing, ChinaJiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security, Hohai University, Nanjing, ChinaPeriods of very shallow water (water depth in the order of 10 cm) occur daily on tidal flats because of the propagation of tides over very gently sloping beds, leading to distinct morphodynamical phenomena. To improve the understanding of the characteristics of velocity and suspended sediment concentration (SSC) surges and their contribution to sediment transport and local bed changes during periods of very shallow water, measurements of near-bed flow, and SSC were carried out at two cross-shore locations on an intertidal flat along the Jiangsu coast, China. Furthermore, the role of surges in local resuspension and morphological change was explored. Results indicate that flow and SSC surges occurred at both stations during very shallow water periods. On the lower intertidal flat, flood surges were erosive, while weaker surges on the middle intertidal flat were not. Surges on lower intertidal flats resulted in local resuspension and strong turbidity, contributing up to 25% of the onshore-suspended sediment flux during flood tides, even though they last only 10% of the flood duration. When surges travel across the flats, conditions change from erosional to depositional. Velocity surges on the middle intertidal flat were too weak to resuspend bed sediment, and the associated SSC surges were produced by advection.https://www.frontiersin.org/articles/10.3389/fmars.2021.599799/fullfield instrumentationcoastal processesvery shallow watersediment transportsuspended sediment concentrationintertidal mudflats |
| spellingShingle | Qian Zhang Zheng Gong Zheng Gong Changkuan Zhang Jessica Lacy Bruce Jaffe Beibei Xu Xindi Chen The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats Frontiers in Marine Science field instrumentation coastal processes very shallow water sediment transport suspended sediment concentration intertidal mudflats |
| title | The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats |
| title_full | The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats |
| title_fullStr | The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats |
| title_full_unstemmed | The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats |
| title_short | The Role of Surges During Periods of Very Shallow Water on Sediment Transport Over Tidal Flats |
| title_sort | role of surges during periods of very shallow water on sediment transport over tidal flats |
| topic | field instrumentation coastal processes very shallow water sediment transport suspended sediment concentration intertidal mudflats |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2021.599799/full |
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