摘要
对荆江马羊洲支汊干河床表面的底形测量和浅层(深度小于2m)层理特征研究表明,这个以年为周期季节性过水的分汊河道河床上的沙纹一般披覆在大沙波表面而形成次级沙纹,沙波属中型的强三维舌形、新月形以及二维绞状,沙波弯曲度、波长及波商由两岸向河道中心增加。根据底形和地形可进一步将河床划分为13个二级河流地貌单位。洪汛期与退水期形成的层理规模明显不同,不足2m厚的层理序列揭示了一个完整的退水过程。干涸的河床为研究现代沉积提供了条件。
Bedforms and top-level stratifications (shallower than 2 metres) have been investigated by 11 cross sampling sections within the secondary distributary channel of Mayangzhou channel island, Jingjiang reach of Yangtze River. On this dried bed, ripples are lying on the sandwaves and arranging as secondary ripples offan, flank, obate and oblique-parallel types. Sandwaves are in middle scale and have the geometry of strong 3-D lobate and lunate types and 2-D linear types. Their sinuosity, wave length and wave height are increasing from the bank side to the center of the channel bed. 13 secondary fluvial channel bed geomophic unites have been divided by bedforms and the bed gradient. This helps to build a bedform distribution and current direction model for this channel. Differences of stratifications formed during flooding and desending seasons have been clearly indicated by the stratification sequence shallower than 2 meters which represents a complete channel water descending process.
出处
《江汉石油学院学报》
CSCD
北大核心
1991年第4期11-14,共4页
Journal of Jianghan Petroleum Institute
