【摘要】 根据现场采集的1 309个表层沉积物样品,分析了珠江河口及邻近海域的表层沉积物特征。在此基础上,应用Gao-Collins的粒径趋势分析模型(GSTA模型),计算了珠江河口及邻近海域表层沉积物的净输运趋势,并结合有关动力沉积背景讨论了其实际意义。结果表明:珠江口及邻近海域表层沉积物类型共有8种,其中以粘土质粉砂和粉砂分布最广泛。受径流、潮流、沿岸流、波浪和陆架环流等动力作用,表层沉积物颗粒呈现出研究区西南部及北部口门附近的泥沙较粗,中部和东部的泥沙较细。东部(即大鹏湾及大亚湾以南的陆架区域)和西南部的分选略好于珠江河口及近岸10 m以浅区域,珠江河口及近岸10 m以浅区域的分选又略好于研究区的中南部区域(万山群岛的东南面及担秆列岛以南的区域),但泥沙总体分选差。不同级配的泥沙分布和沉积特征不一致。珠江河口及邻近海域泥沙运移规律较复杂,珠江河口及近岸区域(10 m以浅)泥沙主要向南和西南运移;外海陆架区泥沙主要向东运移;大亚湾和红海湾以南至60 m以浅区域的泥沙呈现向南运移的趋势。黄茅海北面的泥沙向西南运移;大襟岛和荷包岛以南及两岛之间是高盐陆架水入侵通道,泥沙整体向北运移;黄茅海中部泥沙以垂直落淤为主,水平运移趋势不显著,只略微向西输运,故黄茅海河口湾中西部床面有淤浅的趋势。在(113.52E,21.76N)点附近存在一个巨大的泥沙辐聚中心,其东北、西北和南面泥沙均向该点运移辐聚;在万山岛至桂山岛周边区域泥沙呈现出逆时针方向的环流运移。更多还原

【Abstract】 The author analyzed the characteristics of surface sediments in Pearl River Estuary and the adjacent sea area based on 1309 bed material samples.On this basis,sediment transport trends were identified by the grain-size trends calculated by using the Gao-Collins Grain Size Trend Analysis Model(GSTA model).Its practical significance was discussed by integrating the dynamical sediment settings.The results indicated that there were 8 types of bed materials in Pearl River Estuary and the adjacent sea area,with clayey silt and silt being the dominant type.Under the influences of runoff,tidal currents,wind waves,coastal currents,and continental shelf circulation,the bed sediments in the northern zone close to the estuary mouth and in the southwest zone of the study area were coarse and those in the middle zone and in the east zone of the study area were fine.Sorting of bed sediments in the east zone(southern Dapeng Bay and Daya Bay) and in the southwest zone was a little better than that in Pearl River estuary bay and in the alongshore area with depth of less than 10 m,and sorting in Pearl River estuary bay and in the alongshore area with depth of less than 10m was a little better than that in the south-central zone(southeastern Wanshan archipelago and southern Dangan islands chain),However,the total sorting was poor.The spatial distribution and deposition characteristics of different grain-size sediments were different.The patterns of sediment transport in Pearl River Estuary and the adjacent sea area were very complex.The sediments in Pearl River estuary bay and in the alongshore area with depth of less than 10m were transported mainly southward and southwestward,and those in the outside continental shelf of the southern study area were transported mainly eastward,and those in the east of study area from the Dapeng Bay and Honghai Bay to the area with the depth of 60m were transported southward.The sediments in the northern Huangmaohai Bay were transported southwestward,those in the southern Dajin Island and Hebao Island and between the two islands were transported wholly northward,and those in the center zone of Huangmaohai Bay mostly deposited vertically and were only transported a bit westward horizontally.Therefore,seabed of the Midwest Huangmaohai Bay will become much shallower.Around the point of(113.52E,21.76N) existed a great sediment converging center.Northeast,northwest,and south sediments of the point were all transported to the point.The sediments around the Wanshan Island and the Guishan Island took on an anticlockwise rotation circumfluence transport.更多还原