泥沙研究

基于长江徐六泾观测站2016—2023年实测数据，分析该水域絮凝体、含沙量及分散颗粒的变化特性与影响因素。絮凝作用主要受分散颗粒粒径、径流量、含沙量及黏土含量调控，受自然与人为因素共同影响，水域含沙量呈波动下降趋势，表层和底层年平均含沙量分别从44.0 mg/L、120.6 mg/L降至31.4 mg/L、50.6 mg/L,且存在12个月、6个月及3个月的周期性变化。分散颗粒粒度呈粗化现象，表层和底层年平均中值粒径分别由5.19μm、7.03μm增至5.75μm、7.87μm。颗粒组成变化表现为黏土含量降低、粉砂与砂含量增加，表、底层砂含量分别由1.5%、2.8%增加至3.4%、9.6%。

Based on the measured data at Xuliujing observation station of the Yangtze River from 2016 to 2023, the variation characteristics and influencing factors of flocs, sediment concentration and dispersed particles were analyzed. Results show that flocculation is mainly regulated by dispersed particle size, runoff, sediment concentration and clay content. Affected by both natural and human factors, the sediment concentration shows a fluctuating downward trend: The annual average sediment concentrations at surface and bottom layers decrease from 44.0 mg/L and 120.6 mg/L, respectively, to 31.4 mg/L and 50.6 mg/L, with periodic variations of 12, 6 and 3 months. The dispersed particles are coarsening: the annual average median particle sizes at surface and bottom layers increase from 5.19 μm and 7.03 μm to 5.75 μm and 7.87 μm, respectively. The clay content in suspended sediment decreases, while silt and sand contents increase. The sand contents at surface and bottom layers increase from 1.5% and 2.8% to 3.4% and 9.6%, respectively.