近60年来长江河口河势变化及其对水动力和盐水入侵的影响Ⅱ.水动力

发布时间：2019-04-15 20:59

【摘要】：本文基于本系列论文Ⅰ中数值化的长江河口20世纪50年代、70年代海图获得的岸线和水深资料,以及2012年水深实测资料,设置不同年代模式网格,考虑径流量、潮汐和风应力作用,建立长江河口水动力和盐水入侵三维数值模式,模拟和分析不同年代潮汐潮流、单宽余通量、分汊口水通量和分流比,及其河势变化对它们的影响。最大潮差在3个年代间的变化主要在北支区域,50年代至70年代,北支潮差减小,减小区域集中在北支中段,2012年相比70年代北支潮差增大。单宽水通量在50年代北港大于南港,北支下段向上游输运、上段量值较小,在70年代南港大于北港,北支下段量值较小、上段向下游,在2012年南北港水通量较为接近,北港稍大,整个北支水通量向上游。定量给出了50、70年代和2012年南北支、南北港大潮期间和小潮期间涨潮、落潮和净水量和分流比,结合河势变化分析了不同年代间的变化原因。
[Abstract]:Based on the coastal and bathymetric data obtained from the charts of the Yangtze River Estuary in the 1950s and 1970s, as well as the measured data of the bathymetric data in 2012, the model grids of different ages are set up in this paper, and the runoff is taken into account. Based on tidal and wind stress, a three-dimensional numerical model of hydrodynamics and salt water intrusion in the Yangtze River estuary is established. The tidal current, single width residual flux, bifurcation water flux and shunt ratio, and the effects of river regime changes on them are simulated and analyzed in different ages. The variation of the maximum tide difference in the three years is mainly in the northern branch region. From 1950s to 1970s, the northern branch tide difference decreased, and the decreasing area concentrated in the middle part of the north branch, and increased in 2012 compared with the north branch difference in the 1970s. In the 1950s, the water flux of the north port was larger than that of the south port, the lower part of the north branch was transported upstream, the upper part was smaller, the south port was larger than the north port in the 1970s, the lower part of the north branch was smaller, and the upper part was downstream, and in 2012, the water flux of the north and south ports was relatively close to that of the north-south port. Beigang slightly larger, the whole north branch water flux upstream. In this paper, the rise, ebb, net water and diversion ratio of spring tide, ebb tide and net water volume in the north-south branch of the north-south port and the north-south branch of the port in the 1950s, 1970s and 2012 are quantitatively given, and the causes of the change in different years are analyzed in combination with the change of river regime.
【作者单位】：华东师范大学河口海岸国家重点实验室;
【基金】：国家自然科学基金项目(41476077) 上海市科委重点项目(14231200402)
【分类号】：TV148

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