渤、黄、东海海流和潮汐共同作用下的悬浮物输运、沉积及其季节变化

The Transport and Sedimentation of Suspended Matter and Their Seasonal Variation are Affected by Circulation and Tide Current in the Bohai Sea, the Yellow Sea and the East China Sea

渤、黄、东海是一个水动力状况相当复杂的半封闭宽陆架海,本海区悬浮颗粒物含量高,季节变化明显,影响范围广,是世界上悬浮物含量最高的海域之一。对于该海域悬浮物的输运沉积过程、分布规律以及底质分布等中外学者均进行过比较深入的研究(秦蕴珊,1963;Honjo et al.,1974;Milliman et al.,1985,1986;秦蕴珊等,1987,1989;杨作升等,1992;Li et al.,1997;孙效功等,2000;雷坤等,2001)。然而,以往的研究大都基于实际海洋调查资料,由于受实测资料在时间和空间覆盖范围上的限制,很难从整体上把握渤、黄、东海陆架区悬浮物输运的时间和空间变化规律。数值模拟的方法能很好地克服上述局限,已有学者从不同角度对渤、黄、东海的某些海域的悬浮物进行了模拟研究。

The circulation, tide and tide current in the Bohai Sea, Yellow Sea and East China Sea were relatively successfully simulated by POM (Princeton Ocean Model). Then after the governing equation of suspended matter transport was added into POM, and with due consideration of the mechanism of the sedimentation and re-suspension, the transport, dispersion, sedimentation and erosion of suspended matter affected by circulation and tide current were simulated. Simulated results on the temporal and spatial distribution of total suspended matter concentration revealed and further proved that the seasonal characteristics of suspended matter transport were: storage in summer and autumn; transport in winter and spring in the East China Seas. Shelf circulation has crucial influence on long-term suspended matter transport. The finer the grain size of suspended matter was, the farther it dispersed. The simulated distribution of surface sediment accorded with that measured; and the simulated settling velocity on the mud off Zhejiang coast is similar to the measured. The calculated result of suspended matter exchange showed that net flux of suspended matter from the Yellow Sea to the East China Sea was 5.0×107 tons every year, especially in autumn and winter; the net flux from the Bohai Sea to the Yellow Sea was 1.5×107 tons every year, about 2% of total suspended matter derived from the Yellow River.