长江河口潮流界底形演变机理及其对三峡建坝的响应

The bedform of the tidal current limit of Yangtze Estuary is very sensitive to the interaction of runoff and tidal current. It is dominated by the bidirectional flow and mixed sediments. Exploring the bedform processes at this area can contribute to investigate the seasonal changing of the hydrodynamics induced by the intensive dam construction in the Yangtze catchment. A straight channel near the tidal current limit, the Jiangyin Channel, will be selected to conduct the fieldwork during both the flood and non-flood season. Plenty of advanced devices, including the multi-beam echo-sounder, ADCP, OBS, etc., will be utilized to obtain the 3D-bedform and multiple hydrological parameters. These field data will be compared with the data from physical experiments and the previous studies. The results will contribute to reveal (1) the mechanism of the formation and evolution of the bedforms and the (semi-)quantitative relation with the hydrodynamics around the tidal current limit; (2) the influence of the dam construction on the bedform evolution and the seasonal location variation of the tidal current limit. This study will be conducive to understand the mechanism of bedform processes in the tidal current limit and its response to the construction of the Three Gorges Dam. It will also contribute to provide valuable references for the river channel regulation and engineering construction in the Yangtze estuary.

长江河口潮流界底形对径潮流动力变化十分敏感，其演变主要受双向流与沉积物控制。开展潮流界底形演变机理的研究，有助于揭示流域建坝引起的河口区水文地貌过程的变化。因此，本项目拟选取潮流界附近江阴顺直河段为研究区，以河口底形（沙波）变化为敏感指标，利用多波束底形探测仪、ADCP流速仪和OBS光学浊度仪等仪器，开展洪枯季野外调查工作，以获取同步的三维底形和水文数据。在此基础上，结合水槽实验数据与前人研究成果，分析：1）底形变化的机理，及其与水文变化的（半）定量关系；2）底形变化与潮流界地理位置改变对流域建坝的响应。通过上述研究，探讨长江河口潮流界底形演变机理及其对三峡建坝的响应，为河口整治提供科学依据。

长江河口潮流界底形对径潮流动力变化十分敏感，其演变主要受双向流与沉积物控制。开展潮流界底形演变机理的研究，有助于揭示流域建坝引起的河口区水文地貌过程的变化。因此，本项目拟选取潮流界附近江阴顺直河段为研究区，以河口底形（沙波）变化为敏感指标，利用多波束底形探测仪、ADCP流速仪和OBS光学浊度仪等仪器，开展洪枯季野外调查工作，以获取同步的三维底形和水文数据。在此基础上，结合水槽实验数据与前人研究成果，分析：1）底形变化的机理，及其与水文变化的（半）定量关系；2）底形变化与潮流界地理位置改变对流域建坝的响应。通过上述研究，探讨长江河口潮流界底形演变机理及其对三峡建坝的响应，为河口整治提供科学依据。