南黄海西部日照近海悬浮泥沙分布、输运及控制因素

Distribution, transport and controlling factors of suspended sediment near Rizhao in the west of South Yellow Sea

  • 摘要: 基于2020年10月日照近岸海域大潮期水文泥沙观测资料,研究了海流和悬浮泥沙时空分布特征,利用单宽通量机制分解等方法,探讨了悬浮泥沙输运机制和控制因素。结果表明,日照近岸海域悬浮泥沙浓度平面上呈由岸向海逐渐降低的分布特征,垂向上呈由表层至底层逐渐升高的趋势。悬浮泥沙浓度变化与潮周期流速变化趋势总体一致,但具有滞后效应。研究区单宽净输沙率为4.72~24.68 g/(s·m),近岸单宽净输沙率明显大于远岸输沙率。悬浮泥沙输运以平流输运为主,其次为潮泵效应或垂向净环流输运。研究区水体垂向混合均匀,对悬浮泥沙垂向分布影响微弱。潮流引起研究区悬浮泥沙浓度的潮周期变化,南黄海西部近海悬浮泥沙净输运方向和潮余流方向大体相同,在远岸开阔海域总体呈向南的净输运趋势。研究成果有利于完善南黄海西部近海泥沙输运规律理论成果,对日照近岸工程建设具有一定的指导意义。

     

    Abstract: In this paper, based on the hydrological and sediment observation data collected from the coastal area of Rizhao in October 2020 during the spring tide, the spatial and temporal distribution pattern of ocean current and suspended sediment are studied, and the transport mechanism and controlling factors of the suspended sediment discussed by means of single wide flux mechanism decomposition. The results show that the concentration of suspended sediment in the studied coastal area decreases gradually from shore to sea laterally, and increases gradually from top to bottom vertically. The variation trend of suspended sediment concentration is consistent with the velocity change of tidal cycle, except for the hysteresis effect. The net sediment transport rate per width in the study area varies between 4.72 and 24.68 g/(s·m), and the net sediment transport rate per width near shore is significantly higher than that offshore. The main transport of suspended sediment is advection, followed by tidal pump effect or vertical net circulation. The vertical mixing of water body in the study area is uniform, and its effect on vertical distribution of suspended sediment is rather weak. Tidal current is the major process to cause the tidal cycle change of suspended sediment concentration in the study area. The net transport direction of suspended sediment and tidal residual current are roughly the same in the west coast of the South Yellow Sea, and there is southward net transport trend in general in the far shore area of the open sea. The research results are beneficial to improve the theoretical results of sediment transport pattern in the west of the South Yellow Sea and have certain guiding significance to the engineering construction in the Rizhao coast.

     

/

返回文章
返回