Department of Civil and Environmental Engineering, Seoul National University, Republic of Korea.
Institute of Construction and Environmental Engineering, Seoul National University, Republic of Korea.
Mar Pollut Bull. 2018 Apr;129(1):26-34. doi: 10.1016/j.marpolbul.2018.02.014. Epub 2018 Feb 10.
When mixtures of aggregates and water dredged from the seabed are discharged at the surface into the adjacent water from a barge, coarse sediments sink immediately and fine sediments are suspended forming a plume. Recently, elongated plumes of fine sediment were observed by satellites near a dredging location on the continental shelf. Such plume streaks were longer in certain conditions with seasonality than expected or reported previously. Therefore, the present work studied the appearance of sediment plume with field measurements and numerical simulations and explains the seasonally varying restoring force and thicknesses of the surface mixed layer resulting from the vertical density distribution near the surface, along with mixing by hydrodynamic process. The resulting mixtures, after vertical restoring and mixing with the surroundings, determine the horizontal transport of suspended sediments. A numerical model successfully reproduced and explained the results from field measurements and satellite images along with the seasonal variations.
当从海底挖出的混合物和水从驳船表面排入相邻的水中时，粗颗粒沉积物会立即下沉，而细颗粒沉积物则会悬浮形成羽流。最近，卫星在大陆架上的一个疏浚地点附近观测到了细长的细沉积物羽流。与以前预期或报告的情况相比，在某些条件下，这种羽流条纹的长度具有季节性。因此，本工作通过现场测量和数值模拟研究了泥沙羽流的出现，并解释了由于近地表垂直密度分布以及水动力过程引起的混合作用，导致表面混合层的恢复力和厚度随季节变化的情况。经过垂直恢复和与周围环境混合后，这些混合物决定了悬浮泥沙的水平输运。数值模型成功地再现和解释了现场测量和卫星图像的结果以及季节性变化。
