The existence of the asymmetrical residual transverse circulation flows in pair is discovered in the residual vorticity field along the passage and sandbank cross section . the transverse residual circulation flow is favorable to sediment ' s moving to the peak of sandbank and the development and maintenance of sandbank 首次发现,在潮涨潮落过程中,深槽中及沙脊两侧均存在一组方向相反、不对称余涡度场(余环流场) ,横向余环流的存在将有利于沙脊两侧的泥沙均向沙脊顶运动和堆积,是潮流沙脊的形成和维持重要动力因素。