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基于2008-2014年逐月现场激光粒度仪(LISST)在长江口徐六泾的定点观测数据,分析了河口控制站徐六泾的悬沙絮凝特性,研究给出絮团粒径与有效密度及沉速的关系。统计表明絮团平均粒径变化范围20~120μm,比分散颗粒中值粒径(平均5.3μm)大一到两个数量级。絮团的分形维数主要在1.8~2.4,有效密度变化范围70~600kg/m~3,其随絮团增大呈减小趋势。洪枯季对比表明,洪季絮团沉降速度比枯季大18%,平均沉速分别为0.26mm/s和0.22mm/s,比以往估算得到的长江口浑浊带絮团沉速小。由此说明为更好认识流域到河口的泥沙输运过程,有必要针对长江河口不同区域进行分段的研究。
Based on the observed data of Xishuijiang in the Yangtze River estuary from 2008 to 2014, the spot-by-spot observation data of LISST was used to analyze the sediment flocculation characteristics of XU Liujing River Estuary control station. The floc size and effective density Shen speed relationship. Statistics show that the average size of the flocs varies from 20 to 120 μm, which is one to two orders of magnitude larger than the median diameter of the dispersed particles (average 5.3 μm). The fractal dimension of flocs mainly ranged from 1.8 to 2.4, and the effective density varied from 70 to 600 kg / m3, which decreased with the increase of flocs. The comparison of flood season and dry season show that the flooding velocity in flood season is 18% higher than that in dry season, and the average deposition velocities are 0.26mm / s and 0.22mm / s, respectively. This shows that in order to better understand the process of sediment transport from the river mouth to the estuary, it is necessary to study the different regions of the Yangtze River estuary.