【摘要】 基于对泰国湾164个表层沉积物样品的粒度分析测试结果,使用Gao-Collins沉积物粒径趋势分析方法,研究了泰国湾底质沉积物的分布特征和输运趋势。研究区内的沉积物主要为粉砂、砂质粉砂和粉砂质砂,分选差,分选系数变化范围为1.3~2.9,平均值为1.8,偏度变化范围为-1.8~2.5,平均值为1.2。根据沉积物粒度趋势特征,研究区分为1区、2区和3区3个区域,其中1区的平均分选系数和偏度分别为1.73、0.91;2区沉积物分选系数和偏度分别为1.81和1.33;3区沉积物分选系数和偏度分别为1.91和1.24。1区和2区河口附近广泛分布粉砂和泥等细粒级沉积物(平均粒径为6.5Ф);而1区与2区交界处和3区的近岸区域沉积物主要为粉砂质砂(平均粒径为5.5Ф)。研究区北部、中部和西南部近岸沉积物相比研究区其他地区,分选更差一些。泰国湾沉积物运移受河流、洋流和季风的共同影响,其中1区受控因素为泰国湾湾口的河流,运移方向为从河口向外;洋流是2区南部沉积物的主要运移动力,运移方向为从外围向湾中心;沿岸流是3区沉积物的主要运移动力,使3区沉积物的运移方向为离岸方向。在河流和洋流共同作用下,泰国湾沉积物有向苏梅岛附近运移的趋势。更多还原

【Abstract】 Based on the grain size data acquired from 164 bottom samples,we studied the distribution pattern and transporting trend of the sediments in the Gulf of Thailand(GoT)using the Gao-Collins’ s method for sediments grain size analysis.In general,most of the sediments in the study area are poorly sorted,and the sorting coefficient varies from 1.3to 2.9 with an average of 1.8and the skewness varies from-1.8to 2.5(with a mean value of 1.2).According to the research results,the study area is divided into three provinces,i.e.the provinces 1,2and 3.The sorting and skewness in the province 1are 1.73 and 0.91,and those in the province 2and 3are 1.81,1.33 and 1.91,1.24,respectively.It means that finegrained sediments(silt and mud)with mean grain size of 6.5Фare widely distributed in provinces 1and 2,while the coarse-grained sediment(silty sand)with mean grain size of 5.5Фare mainly distributed in the cross area between province 1and 2and the near-shore area of province 3.The sorting of sediments from the coastal areas including northern-,middle-and southwestern parts of GoT is poorer than that from other regions.We suggest that sediment transport in the GoT is mainly controlled by three factors,namely rivers,ocean current and East Asian monsoon.In details,for the provinces 1,the sediment transport is controlled by rivers which take sediments from estuaries into deep-water areas.For the province.2,ocean current dominates the sediment transportation in the peripheral part of the province to the center of GoT.As for the province 3,coastal current plays a critical role to move sediments away from the nearshore area.Under the influences of these three factors mentioned above,a sediment depocenter is formed around the Sumui Island.更多还原