江苏王港潮间带表层沉积物特征及输运趋势

潮滩沉积物粒度参数可以用来反映沉积物沉积的水动力条件和沉积环境。根据对江苏王港潮间带采集的15 4个表层样品的粒度资料进行分析,结果表明,沉积物类型以粉砂为主;随着水动力环境由海向陆的减弱,沉积物粒度参数表现出有规律的变化趋势,即由岸向海粒径具有粗化趋势,分选变好,逐渐正偏并达到近对称。研究区与世界其他地区的潮滩在沉积特征上有较大差异,主要是由于沉积物来源、水动力环境及受生物作用的强弱程度不同所致。沉积物输运趋势分析显示,该地区沉积物输运主要受当地潮波特征、大型人工建筑物、地貌形态及生物作用的影响;在低潮线附近主要向西北方向输运,随着向陆地方向的延伸,沉积物由向西输运逐渐转变为向南输运。

Surface Sediment Characteristics and Transport Trends on the Wanggang Intertidal Flat, Jiangsu Province

Sediment parameters of inter tidal flat are related to the depositional hydrodynamic conditions associated with the local sedimentary environment. During July August, 2000, 154 surface sediment samples were collected on the intertidal flat of Wanggang. The sediment samples are then analyzed using Mastersize2000. Further, the regression analysis shows that the significant relationships are present between the sediment parameters, and as well with ( M z Φ M d Φ). In addition, the grain size diameters decrease landward with the decreasing of the hydrodynamics. Five types of sediments have been identified for the Wanggang intertidal flat:fine sand, silty sand, sandy silt, silt and clayey silt. In brief, there are two main sediment types, i.e. silt and sand with the percentages of 57.8% and 42.2% respectively. These results differ from other intertidal flats associated with different sediment sources, hydrodynamic environments and bio influences. The results of grain size trends show that the sediments mainly transport northwestward near the sub tidal zone; but southward, southwestward and southeastward, which are related to tide regimes, local landscape, large human constructions and the biological activities.