长江潮区界上界河槽浅层沉积结构探测研究

Sub-bottom Sedimentary Structures Research and Detection at the Upper of Tidal Limit in the Chang Jiang River

研究地层沉积结构是认识河流变迁历史的重要手段之一,潮区界作为河流物质和能量传输的关键界面之一,于2015年洪季,利用浅地层剖面仪对长江潮区界上界河段河槽浅地层结构进行了"覆盖式"探测。结果表明:长江潮区界上界河段河槽床面发育了大量沙波,尺度较大,陡坡明显朝向下游;崇文洲下游两侧水道中沙波发育较少,尺度也较小;浅层沉积结构显示该河段部分河槽床面以下存在4处不同形态的地质构造。

Sedimentary structure is one of the important methods on the understanding o f the migration of river. However, as the momentous interface of the material and energy transportation, there has never been a report of the sub-bottom sedimentary structure research at the upper of the tidal limit in the Chang Jiang River.＂ Full coverage＂ detection by a sub-bottom profiler is made at the upper of the tidal limit in the Chang Jiang River from July 2015 to August. The results show that a lot of symmetry-to-downstream dunes develop at the upper of the tidal limit in the Chang Jiang River （ Chongwenzhou tail）. In contrast, dunes develop on both sides of the downstream waterway of the Chongwenzhou tail with a smaller scale in the height and spacing.The sub-bottom sedimentary structure shows that there are layers developed in part of the Guichi waterway under the riverbed.