钦州湾悬浮泥沙特征

钦州湾由于湾内外特殊的海洋动力、泥沙来源和地形地貌条件,导致海湾悬浮泥沙特性存在较大差异。通过2007年和2010年钦州湾13个站位的实测悬浮泥沙含沙量数据,总结了钦州湾的泥沙来源,分析了钦州湾悬浮泥沙的空间分布特征、运移趋势和输沙能力。研究结果表明,钦州湾泥沙主要来自河流输沙、海向来沙及岸滩侵蚀;水体含沙量最大值空间分布整体表现出"外湾 > 内湾 > 湾颈"的特点,平均值由内湾到外湾逐渐减小;水体垂向平均含沙量最大值出现层位不同,内湾表底层平均含沙量趋于一致,但中层略大,而外湾由表层至底层存在渐进变化;潮流强度、地形特征及泥沙来源是影响悬浮泥沙空间分布的主要因素;悬浮泥沙输运主要受潮流控制,输沙强度呈"湾颈 > 外湾 > 内湾"特点,总体输沙趋势由湾顶向湾外、沿落潮流由北向南输运。

CHARACTERS OF THE SUSPENDED LOAD IN QINZHOU BAY

Owing to the specific characteristics of ocean dynamics, sediment sources and topographic features, the suspended load is differentiated from place to place in the Qinzhou Bay. In this paper, we studied the sediment source, the spatial distribution pattern and the transport trend and capacity of the suspended load through the measured data from 13 stations in 2007 and 2010 respectively. The results show that the sediments from the Qinzhou Bay are mainly coming from surrounding rivers, open seas and coastal erosion. Spatially, the distribution of maximum concentration of suspended load is in a pattern of "Outer bay > Inner bay > Neck", whereas the average decreases gradually from inner bay to the outer. In vertical sections, the average maximum concentration of suspended load appears in different positions. It tends to be consistent in the surface and bottom layers in the Inner Bay, but slightly higher in the middle layer. In the outer bay, however, it gradually increases from the surface to the bottom. Tidal current, topography and sediment source are the main influence factors. The transport of suspended load is mainly controlled by tidal current and the transport intensity decreases from the neck of the bay to the outer bay and inner bay. The overall trend of sediment transport is from the top bay towards the outer bay from north to south along the ebb and flow direction.