长江口徐六泾水域近期的悬沙变化特征OA

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 parti-cles were analyzed.Results show that flocculation is mainly regulated by dispersed particle size,runoff,sedi-ment 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 varia-tions 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.