内孤立波作用下南海北部陆坡沙波形成过程实验模拟

发布时间：2019-05-23 07:59

【摘要】：为探究内孤立波作用下陆坡坡面沙波形成机制,在室验水槽内模拟恒定振幅下凹型内孤立波对砂质粉砂、黏土质粉砂、细砂三种沉积物坡面连续作用过程,利用超声地形自动测量分析系统(TTMS)、电阻率探针、温盐深仪(RBR·CTD)分别监测内孤立波作用前后土坡高程变化,作用过程水土界面实时变化及悬浮物浓度时空变化,基于测试结果分析沉积物悬浮、运移及沉积过程特征。研究表明,沙波形成过程中不同类型沉积物悬浮-运移方式不一致,在恒定振幅内孤立波作用下,砂质粉砂发生悬浮向坡顶运移,其中较大的颗粒在坡顶发生沉积,较小颗粒沿坡面运移到坡底;黏土质粉砂发生悬浮后同时向坡顶和坡中运移,在坡顶和坡中位置形成雾状层沿等密度层水平扩散;砂质粉砂运移方式主要为推移质运动,黏土质粉砂主要为悬移质运动。内孤立波形成的沙波体坡顶无尖刃,较为圆滑,两坡不对称,迎流面薄,背流面厚。
[Abstract]:In order to explore the formation mechanism of sand wave on continental slope under the action of internal solitary wave, the continuous action process of concave internal solitary wave on sandy silt, clay silt and fine sand slope was simulated in a laboratory flume. The changes of soil slope elevation before and after internal solitary wave action, the real-time change of soil and water interface and the temporal and spatial variation of suspended matter concentration were monitored by ultrasonic topographic automatic measurement and analysis system (TTMS), resistance probe and temperature and salt depth instrument (RBR 路CTD), respectively. Based on the test results, the characteristics of sediment suspension, migration and sedimentary process are analyzed. The results show that the suspension-transport modes of different types of sediments are different in the process of sand wave formation. Under the action of solitary waves in constant amplitude, sand silt is suspended and migrated to the top of the slope, in which the larger particles are deposited at the top of the slope. Smaller particles migrate to the bottom of the slope along the slope. After suspension, clay silt moves to the top and slope at the same time, and the foggy layer diffuses horizontally along the equal density layer at the top and middle of the slope, and the migration mode of sandy silt is mainly bed load movement, and the clay silt is mainly suspended movement. The sand wave slope formed by internal solitary wave has no sharp edge, is smooth, the two slopes are asymmetrical, the upcurrent surface is thin, and the backflow surface is thick.
【作者单位】：中国海洋大学环境科学与工程学院;山东省海洋环境地质工程重点实验室中国海洋大学;
【基金】：国家自然科学基金重大科研仪器研制项目(41427803)资助~~
【分类号】：P731.2;P737.2

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