应用声、光学仪器原位观测海底浮泥层动态变化的对比研究  

Comparative Study of In-Situ Observation of Dynamics of Fluid Mud Layers on the Seafloor with Acoustic and Optical Instruments

作　　者：刘晓磊 马路宽 张红 陆杨 陈安铎 张淑玉 LIU Xiao-Lei;MA Lu-Kuan;ZHANG Hong;LU Yang;CHEN An-Duo;ZHANG Shu-Yu(Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China;Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China)

机构地区：[1]中国海洋大学山东省海洋环境地质工程重点实验室,山东青岛266100 [2]青岛海洋科学与技术试点国家实验室海洋地质过程与环境功能实验室,山东青岛266237

出　　处：《中国海洋大学学报（自然科学版）》2021年第1期86-93,共8页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(41877221);山东省自然科学基金项目(ZR2019QD001);青岛海洋科学与技术试点国家实验室开放基金项目(QNLM20160RP0110)资助。

摘　　要：海底浮泥层动态变化是研究海底沉积物输运及地形地貌演变的重要内容。针对浮泥层关键特征参数(悬浮泥沙浓度、上下界面),目前国际上主要采用声学和光学仪器进行观测,但不同仪器受限于观测原理,适用范围存在一定的局限性。通过潮滩试验,模拟浮泥层动态变化过程,对比不同仪器观测悬浮泥沙浓度和海床界面高程的效果。结果显示,在较低悬浮泥沙浓度(<10 g/L)情况下,高密度悬沙浓度剖面仪ASM、声学多普勒流速仪ADV与声学多普勒流速剖面仪ADP均能完成悬浮泥沙浓度的观测要求,声学蚀积仪AA400与ASM均能得到准确的海床高程。在悬沙浓度较高的情况下(>20 g/L),声波衰减显著,ADP相对于ASM的误差最高可达30.95%,难以准确测量水体悬沙浓度;随着悬沙浓度的升高(>30 g/L),AA400无法得到连续有效的海床界面位置,ASM也超出测量量程,因此,30 g/L的悬沙浓度可作为风暴过程中高浓度浮泥层形成的标志。在现场复杂海况下开展海底浮泥层动态变化研究需要多种仪器相互配合。The dynamics of fluid mud layers on the seafloor play an important role in the study of seabed sediment transport and the topography evolution.Acoustic and optical instruments are mainly used to observe the key characteristic parameters of the fluid mud layers(i.e.,suspended sediment concentration and upper and lower interfaces)in the world.Due to the different observing principles,however,there are certain limitations for different instruments in application.This paper compares the effects of observing the suspended sediment concentration and the seabed interface elevation with different instruments,by simulating the dynamic process of the fluid mud layers on a tidal flat.The results show that in the case of low suspended sediment concentration(<10 g/L),the Argue Surface Meter(ASM),Acoustic Doppler Velocimetry(ADV),and Acoustic Doppler Profilers(ADP)can meet the observation requirements of suspended sediment concentration,and the Echo logger(AA400)and ASM can obtain the elevation of seabed accurately.In the case of higher suspended sediment concentration(>20 g/L),the relative error of ADP relative to ASM can reach 30.95%due to the significant sound attenuation effect,which makes it difficult to measure the suspended sediment concentration accurately by ADP.With the increase of suspended sediment concentration(>30 g/L),AA400 cannot obtain continuous and effective seabed interface elevation,and ASM is difficult to work because of overrange.So the SSC of 30 g/L can be further used as an indication for the high-density fluid mud formed under storm waves.The study of dynamics of fluid mud layers under the complex sea conditions requires multiple instruments to cooperate with each other.

关 键 词：海底浮泥层 声学 光学 悬浮泥沙浓度 海床界面 

分 类 号：O441[理学—电磁学]