摘要
水体中悬浮泥沙浓度的变化过程是泥沙运动的重要表现形式,客观反映了不同的水动力环境。根据蓬莱近岸海流、悬浮泥沙等实测资料,分析了研究区悬浮泥沙浓度时空分布特征和变化规律,并初步探讨了悬浮泥沙浓度变化对潮流的响应。研究结果表明,时间上,研究区平均含沙量落潮段大于涨潮段,大潮期大于小潮期;不同层位悬浮泥沙浓度随时间的周期性波动大潮期强于小潮期,悬浮泥沙浓度时间周期变化的9~16h尺度在研究区具有全域性。空间上,研究区各层平均悬浮泥沙浓度由表层至底层递增,悬浮泥沙浓度垂向梯度变化大潮期群岛区最小,海峡区最大,小潮期西部区最小,东部区最大,悬浮泥沙浓度的垂向分布类型以指数型、斜线型为主;潮周期平均悬浮泥沙浓度群岛区最大,海峡区次之,西部区最小;悬浮泥沙浓度潮周期变化与该海域潮流流速周期变化具有较好的相关性,潮流流速超过40cm/s时,发生明显的再悬浮现象。
The change in suspended sediment concentration of a water body is an important manifestation of sediment movement,which may objectively reflect the difference in hydrodynamic environment.Using the measured data of nearshore current as well as the suspended sediment from the Penglai area,this paper concentrates itself into the temporal and spatial distribution patterns and variations in suspended sediment concentrations in the area,and their response to tidal current.Results show that the average sediment concentration in the ebb tide period is usually larger than that in the high tide period,and that in the spring tide is larger than that in the neap tide.The cyclical fluctuation of the suspended sediment concentration in different layers is stronger in the spring tide rather than in the neap tide.The periodic change in the suspended sediment concentration on a scale of 9 ~16 hin the study area is same as the global.With regard to the spatial distribution,the average suspended sediment concentration increases from the surface to the bottom.During the spring tide,the vertical gradient of the suspended sediment concentration is the smallest in the Island area,but the largest in the Strait area.However,suspended sediment concentration in a neap tide is the smallest in the west but the largest in the east area.And the vertical distribution of suspended sediment concentration is in an exponential and linear relationship with depth.In a tidal cycle,the largest average suspended sediment concentration is at the Island area,followed by the Strait area,with the western region as the smallest.There is a good correlation between the suspended sediment concentration and the tidal current velocity.When the current velocity exceeds 40 cm/s,significant resuspension will occur.
出处
《海洋地质前沿》
CSCD
2017年第12期13-23,共11页
Marine Geology Frontiers
关键词
蓬莱近岸
悬浮泥沙
时空分布
潮流
Penglai coast
suspended sediment
temporal and spatial distribution
tide
