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2003年7月上旬在江苏大丰潮间带下部采用MIDAS-400观测系统进行了6个潮周期的高分辨率沉积动力观测,并根据观测数据计算了浪流共同作用下的底部切应力及推移质输运率.同时,在100m×200m的试验样方内、以10m为间距采集了大、小潮滩面干出时的表层底质样,用粒度趋势分析方法分析底质净输运格局.结果表明,由于波浪的作用,使得海底沉积物活动性得到较大增强,推移质输沙率有较大增加;潮周期内的单宽推移质净输运量约为30~150kg·m-1,均垂直海岸线向海净输运.粒度趋势分析显示,潮滩物质的输运格局复杂,水动力强弱及局部地形(如潮沟)是重要的影响因素.在靠近流速观测点的区域,与大潮期间的结果相比,小潮期间的粒度趋势与输沙公式计算的推移质输运方向更加接近,小潮期间的粒度趋势平均矢量大于大潮期间的平均矢量,表示小潮期间采样厚度所代表的时间尺度更接近于潮周期时间尺度.
In the early July 2003, a MIDAS-400 observation system was used in the lower part of the Dafeng intertidal zone in Jiangsu Province to conduct high-resolution depositional dynamic observations of six tidal cycles. Based on the observed data, the bottom shear stress and displacement Meanwhile, in the 100m × 200m experimental plots, the surface sediment samples collected at 10m intervals were collected and the net sediment transport pattern was analyzed by particle size trend analysis. The results show that the seabed sediment activity is greatly enhanced due to the wave action, and the bed transport sediment transport rate increases greatly. The net mass transport per unit width of the tidal cycle is about 30-150 kg · m -1 , And the vertical coastline was transported to the sea-net.The grain size trend analysis showed that the transportation pattern of tidal flat was complex, the hydrodynamic strength and the local topography (such as tidal channel) were the important influencing factors.In the area close to the flow rate observation point, Compared with the results during the tide, the trend of grain size during the tide was closer to that of the plutonic transport calculated by the formula of sediment transport. The average trend vector of grain size during the tide was greater than the average vector during the tide, indicating the time represented by the sample thickness during the tide ruler Degree closer to the tidal cycle time scale.