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2015年2月1-7日采用多波束测深系统对长江口南槽河段进行走航测量,结合人类活动强干扰下的海图水深数据及河槽表层沉积物资料,探讨近期长江河口南槽河段河槽冲淤变化与微地貌特征。结果表明:在三峡工程等流域大型工程和深水航道治理工程等河口工程的共同影响下,近期南槽河段上段持续受到冲刷且冲刷态势向下延伸,在1995-2013年南槽河段(中下段和口外段)共淤积1.96亿m~3,平均每年淤积0.11亿m~3;2002-2013年南槽河段(上段至口外段)共冲刷4.98亿m~3,平均每年冲刷0.45亿m~3;在其冲刷环境的影响下,近期南槽底床上除发育平滑床底外,还广泛发育冲沟和凹坑等侵蚀性微地貌,而上段河槽持续受到冲刷导致底沙推移质运动增强,发育了小区域的沙波微地貌,这是首次在南槽观测到的沙波。
The multi-beam sounding system was used to measure the south channel of Yangtze River estuary from January 1 to 7, 2015. Based on the charts of water depth data and surface sediment data under strong human activity, Scouring and silting variation and micromorphological features in fluvial channel of. The results show that under the common influence of the Three Gorges Project and other large-scale river basins, such as the large-scale river basin engineering and the deep-water channel regulation project, the upper reaches of the Nanchuan reach have been continuously washed away and the erosion trend extends downward. In the period from 1995 to 2013, The lower part and the outer part of the mouth altogether deposited 196 million m 3, with an average siltation of 111 million m 3 per year. During 2002-2013, a total of 498 million m 3 were washed in Nancao River section (from the upper section to the mouth of the mouth), with an average annual erosion of 45 million m ~ 3; under the influence of its erosion environment, in addition to the smooth bed at the bottom of the southern groove, the erosion of microfacies such as gully and dike is also widely developed. , The development of a small area of sand wave micro-topography, which is the first time observed in the southern trough sand wave.