海洋盐度场对细粒沉积物临界剪应力影响

INFLUENCE OF WATER SALINITY ON CRITICAL SHEAR STRESS OF FINE-GRAINED SEDIMENTS

黄河口海域盐度变化受黄河入海径流量、气候及海洋动力条件的影响,河口沉积物的沉降、固结及侵蚀等动力学行为与黄河口海域盐度变化有密切关系。为研究不同盐度环境对河口沉积物抗侵蚀性变化的影响,在现代黄河三角洲刁口河路潮滩上进行原位试验,模拟不同盐度的沉积环境,使用黏结力仪（CSM）对细粒沉积物进行抗侵蚀性测试。结果表明细粒沉积物的临界剪应力为0.728～1.581Pa,且随着沉积环境盐度增加,细粒沉积物的临界剪应力呈线性增加。当沉积环境盐度增加1时,其临界剪应力增加约0.02Pa。

Climate and ocean dynamic conditions always affect water salinity in the Yellow River Estuary,and the dynamic behavior of estuarine sediments is closely related to the salinity fields.In order to study the impact of different environment onto the erosion-resistance pattern of estuarine sediments,in-situ measurement of the erosion and resistance of fine-grained sediment have been conducted using CSM（Cohesive Strength Meter）on the tidal flat of the modern Yellow River delta,simulating different salinity fields.The results show that the critical erosion shear stress of fine-grained sediments varies between0.728～1.581 Pa.The critical shear stress of fine sediments linearly increases with the increase in salinity.When the salinity increases by 1,corresponding critical shear stress increases about 0.02 Pa.