潮汐环境下细颗粒泥沙沉降速度研究述评Ⅲ——沉速的影响因子

Reviews on settling velocity of fine sediment in tidal environment 3: Controlling factors

作为"潮汐环境下细颗粒泥沙沉降速度研究述评"的第3部分,在前人大量理论和试验研究的基础上,对决定细颗粒泥沙沉降速度最重要的3个因子(含沙量、盐度和温度)影响沉速的方式进行了综述。通过对比与分析认为:1)含沙量是影响沉速的主要因子之一,当含沙量在一定范围内,含沙量增加沉速增加;当超越一定限度,含沙量增加,沉速反而减小,存在一个最佳絮凝含沙量区间。2)温度与沉速的关系还需进一步探索;盐度与沉速的关系也存在一定争议,可能存在最佳絮凝的盐度条件。3)含沙量、盐度和温度均能显示其对细颗粒泥沙沉降速度程度不一的影响力,且各因子对沉速的影响关系并非单一、较为复杂,不同地域、时段和区段某些关键参数的差异较大。

This paper is the third part of a series review on the settling velocity of fine sediment in tidal environment. On the basis of the afore-mentioned contexts and related literatures, the influential factor of determining the settling velocity is analyzed. The findings of this review are as follows： 1 ） Suspended sediment concentration （SSC） is taken as one of the major determinants for the settling process of fine sediment. When SSC is in a small range, the settling velocity is increasing with SSC, but it will fall down with SSC when the magnitude of SSC is over a greater value; 2） The dependency of temperature on the settling velocity needs more attention in the future, and the salinity has significant contribution to the settling velocity; 3） SSC, temperature and salinity all manifest their influences on the settling velocity to different extents. The dependency between SV of estuarine fine sediments and its various determinants （ SSC, salinity, temperature, etc. ） rely highly on some given conditions.