渤海泥沙对极端天气的动力响应:进展与展望

Sediment dynamics in the Bohai Sea under extreme weather: advances and prospects

  • 摘要: 极端天气事件是塑造海岸地貌的关键因素,揭示其泥沙动力响应机制对海岸带韧性管理至关重要。本文综合现场观测、卫星遥感及数值模拟成果,按照泥沙起动与再悬浮、悬沙时空分布重塑及通量与源汇演变的过程链条,系统综述渤海极端天气下泥沙动力响应研究进展。研究表明:波流耦合使底部剪切应力增至常态的数倍至数十倍,海床液化使侵蚀速率提高5~10倍,二者共同构成泥沙大规模再悬浮的核心机制;极端事件期间悬沙浓度较常态提高10~100倍,高浑浊度带扩散路径受风场显著调控;台风与寒潮动力机制存在分异,单次台风可贡献全年泥沙净通量的5%~33%,寒潮以持续累积作用为主,并可引发源汇格局快速转换;据此提出“事件驱动-地貌调整-响应演变”正反馈机制。未来应聚焦高浓度浮泥流变特性观测、极端事件群集累积地貌效应及智能预测体系构建,以支撑渤海海岸带韧性治理。

     

    Abstract: Extreme weather events are major drivers of coastal geomorphic change, and understanding the mechanisms governing sediment-dynamic responses to these events is important for resilience-oriented coastal management. Drawing on field observations, satellite remote sensing, and numerical simulations, this paper systematically reviews research progress on sediment dynamic responses in the Bohai Sea under extreme weather conditions. The review is structured around the process chain of sediment entrainment and resuspension, reorganization of the spatiotemporal distribution of suspended sediment, and abrupt changes in sediment fluxes and source-sink evolution. Existing studies indicate that: ① Wave-current coupling increases bottom shear stress to several to several tens of times the background level, while seabed liquefaction increases erosion rates by a factor of 5-10; together, these processes are the primary drivers of large-scale sediment resuspension. ② During extreme events, suspended sediment concentrations increase by one to two orders of magnitude relative to normal conditions, and the dispersal of high-turbidity zones is strongly controlled by wind field. ③ Typhoons and cold surges operate through markedly different hydrodynamic forcing mechanisms: a single typhoon may account for 5%—33% of the annual net sediment flux, whereas cold surges act mainly through persistent cumulative forcing. Both can rapidly reconfigure source-sink patterns. On this basis, a positive-feedback framework of “event forcing, geomorphic adjustment, and response evolution” is proposed. Future research should prioritize observations of the rheological properties of high-concentration fluid mud, assessment of the cumulative geomorphic effects of clustered extreme events, and development of intelligent forecasting systems to support resilience-oriented governance of the Bohai coastal zone.

     

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