黄河口附近海域表层悬浮体分布及粒度特征

SPATIAL DISTRIBUTION AND GRAIN-SIZE CHARACTERISTICS OF SUSPENDED MATTERS IN SURFACE WATER OF YELLOW RIVER MOUTH

利用2001年7月进行的两船同步走航调查资料,结合同一时期的陆地卫星合成图像,对枯水期黄河口表层悬浮体空间分布和粒度特征进行了研究。低潮时,黄河河口表层悬浮体含量、温度、盐度在河口口门外5 km范围内变化迅速,表层悬浮体含量和温度向海方向呈指数方式迅速降低,悬浮体含量由519 mg/L下降到20-30mg/L,温度则下降4℃左右;盐度则由1升至33。表层悬浮体含量的变化与表层水体温度、盐度变化有很好的对应关系,温度、盐度变化反映了河流注入的淡水在表层与海水的混合过程。与调查时期接近的一景遥感图像（RGB321）对照,可以看出图像色调变化与测量数值的变化比较吻合。悬浮体平均粒径为6.64-5.26Φ,以粉砂为主。沿测线由河口向海方向,粒度成分和粒径的变化趋势明显,粒径逐渐变粗,黏土成分减少而砂的成分增多,这可能与絮凝作用有关。

Data from two-vessel investigation in Yellow River delta have been used to examine the surface bouyant plumes during the ebb period,together with the remote sensing image. Concentration of suspended matters, water temperature and salinity change dramatically in surface water within 5 km beyond Yellow River delta; concentration descreases from 519 to 20-30 mg/L and temperature drops by 4℃, while water salinity increases from 1 to 33. These variations correspond with each other, showing the mixture of river outflow with seawater. The remote sensing image indicates complicated pattern of suspended matter scattering, which can correlate with the field data. Mean grain size of suspended matters in surface water range from 6.64 to 5.26 Φ,coarsing towards the sea. Granulometric parameters of surface water at the Yellow River mouth are different from those of the Yangtse River estuary.