海南岛西南海底沙波形态和活动性的空间差异分析  

ANALYSIS ON SPATIAL DIFFERENCES OF MORPHOLOGY AND MOBILITY OF THE SUBMARINE SAND WAVES IN SOUTHWEST HAINAN ISLAND

作　　者：李泽文[1,2] 阎军[1] 栾振东[1] 王小红[3] 

机构地区：[1]中国科学院海洋研究所 中科院海洋地质与环境重点实验室,青岛266071 [2]中国科学院研究生院,北京100049 [3]国家海洋局东方海洋环境监测站,海南东方572600

出　　处：《海洋地质动态》2010年第7期24-32,共9页Marine Geology Letters

摘　　要：利用GeoSwath Plus和Seabat8101多波束测深系统于2007年10月和2009年9月对海南岛西南沙波区进行了高精度水深测量,利用所得数据对近岸区和远岸区两个水深相差较大区域的沙波几何形态和沙波迁移速率做了对比分析,探讨了沙波几何形态和活动性的空间差异及其控制因素。远岸研究区与近岸研究区沙波几何形态和沙波迁移速率体现在沙波规模及形态、陡坡倾角和倾向、沙波迁移速率和沙波迁移方向及偏转角度。远岸区域沙波为近于对称的直线型沙波,波高0.5～2.3 m,波长13.2～69.1 m,陡坡倾角4.3°～7.4°;近岸区域沙波为新月形沙波,波高3.1～6.5 m,波长41.5～216.6 m,沙波陡坡倾向南,陡坡倾角8.7°～12.9°。远岸研究区沙波向西北方向迁移,沙波迁移速率多为15.0～20.0 m/a,最大34.9 m/a;近岸区域沙波向南迁移,沙波迁移速率0～12.65 m/a。沙波的迁移速率主要受底流流速和沙波波高控制,在两者的综合作用下,近岸研究区沙波迁移速率小于远岸研究区沙波迁移速率。在频繁的热带气旋作用下,近岸研究区沙波迁移方向发生逆时针偏转。The high-resolution water-depth measurement in sand wave areas in southwest Hainan Island was carried on in October of 2007 and September of 2009 by using GeoSwath Plus and Seabat8101 multi-beam echo sounding system. Based on the seabed topography data, the comparative analysis of geometrical feature and migration rate between nearshore zone and far-shore zone with large difference in water depth was done. Furthermore, the spatial difference of geometrical feature and mobility and their control factors were discussed. The study results show that： The sand wave is nearly symmetri- cal linear pattern in the offshore area, the wave height of sand waves is 0. 5～2.3 m, and the wave length is 13.2～69. 1 m, the lee slopes tend to south, the angles of inclination of which are in the range of 4. 3°～ 7.4°. The sand wave is of crescent shape in the inshore area, the wave height is 3.1～6.5 m, and the wave length is 41.5--216.6 m, the lee slopes tend to south, the angles of inclination of which are in the range of 8.7°～ 12.9°. Sand waves in the offshore area migrate to NW, and most with a speed from 15.0 m/a to 34. 9 m/a, the maximum speed is up to 34.9 m/a. Comparatively speaking, the sand waves in the inshore area migrate relatively slowly with a speed of 0--12.65 m/a. The migration of sand waves is mainly affected by the near-bottom flow velocity and wave height of sand waves. Under the combining effect of the two factors, sand waves in the offshore area migrate faster than those in the inshore area. Due to frequent tropical cyclones passing through the study area, the migration direction of sand waves in the inshore area turned up counterclockwise deflection.

关 键 词：沙波 形态 活动性 迁移速率 

分 类 号：TV148.5[水利工程—水力学及河流动力学]