长江口南槽非均匀细颗粒泥沙起动流速的近似估算

Approximate Estimations of Threshold Velocities for Non-uniform Fine Sediments at the South Passage of the Changjiang Estuary, China

利用文献中的泥沙起动流速公式,推导出非均匀细颗粒泥沙起动流速近似估算公式。采用长江口南槽定点测量涨落潮过程中水深、水面以下1m的流速与近底床悬沙粒径d95资料,拟合该近似估算公式。估算结果表明:近底床悬沙粒径d95小于0 06mm的细颗粒泥沙起动流速值大于已有水槽实验值。

Referring to the existing literatures, an approximate equation to estimate threshold velocity for nonuniform fine sediments is derived. This equation is fitted by the mean water depth, the flow velocity at 1 m below the water surface and the nearbottom suspended sediment particles sizes d95, which are collected from one monitoring station during flood/ebb tides at the South Passage of the Changjiang Estuary. Results suggest that the threshold velocities for nonuniform fine sediments (d95<006 mm) are larger than the laboratory experimental data in the literatures.