渤海湾季节性悬浮体输运过程与机制

Bohai Bay is rich in resources and influenced by natural and human activities. The water exchange and suspended sediment transporting process directly affects the ecological environment and the geomorphologic evolution. The winter-summer circulation and the suspended sediment concentration in Bohai Bay show significant three-dimensional spatio-temporal distribution characteristics, the influence mechanism of which is complicated. Most of the present research focused on the seasonal variation of the suspended sediment distribution, or the variation process of the suspended sediment concentration in local area of Bohai Bay. It is still lack of the sedimentary dynamic observation and research about the suspended sediment transporting process of the whole Bohai Bay. This project application intends to use the in-situ observations in Bohai Bay about ocean current speed, the temperature-salinity-turbidity and the suspended sediment concentration in different seasons, combined with historical data and existing research achievements, in order to clarify the seasonal variation and spatio-temporal pattern of the suspended sediment transportation in Bohai Bay. A three-dimensional hydrodynamic numerical model will be set up for the research of the tidal cycle variation and spring-neap difference of the seasonal suspended sediment transportation in Bohai Bay. On this basis, several numerical model scenarios will be implemented to illustrate the mechanism of the seasonal suspended sediment transportation driven by the wind, the tide and the river runoff in Bohai Bay.

渤海湾资源丰富并受自然和人类活动共同影响，其水体交换和悬浮体输运过程直接影响该海域内外的生态环境和地形地貌演变。冬夏季环流和悬浮体浓度在渤海湾呈现显著的三维时空分布特征，其影响机制较为复杂，目前研究关注较多的是渤海悬浮体分布的季节性变化，或者渤海湾局部海域悬浮体浓度变化过程，缺乏渤海湾整个海域的季节性悬浮体运移过程的现场观测和研究。本申请拟采用渤海湾不同季节海流、温盐浊、悬浮体浓度的观测资料，结合历史资料和已有的研究成果，阐明渤海湾悬浮体的季节性分布特征和时空运移格局；并结合三维沉积动力数值模型，研究渤海湾不同季节悬浮体输运的潮周期变化和大小潮差异；以此为基础，设置多种组合条件的数值实验，研究风、潮汐、径流因素对渤海湾季节性悬浮体输运的驱动机制。

渤海湾及其周边城市作为我国重要的经济发展区之一，从不同时间尺度上认识渤海湾区域的沉积动力过程及其环境效应，有利于推进对该海域沉积动力学和源汇过程研究的进一步认识，对陆海统筹、 区域环境可持续发展具有重要的意义。本项目基于以上项目研究背景和科学意义，根据渤海湾内外多个站位的海流、温盐、悬沙浓度连续观测资料，揭示渤海湾内外潮流特征、 悬浮体浓度和浊度的时空分布特征，结合不同季节渤海湾内站位的实测资料，分析相应海域悬浮体的季节性分布特征和时空运移格局。 后续，项目的主要研究内容是结合实测资料的结果，运用数值模拟手段， 研究渤海湾不同季节悬浮体运移过程在潮周期内和大小潮尺度上的变化规律，阐明水体层化混合过程对渤海湾悬浮体输运的控制作用， 揭示风、潮汐和径流对渤海湾悬浮体输运的驱动作用。