海南岛三亚港现代沉积速率的研究

DETERMINATION OF RECENT SEDIMENTATION RATES IN SANYA HARBOUR, HAINAN ISLAND

对1988年所采集的海南岛三亚港6个沉积柱样作了沉积结构及210Pb放射性分析。结果表明，三亚港潮汐通道及航道上，沉积物主要为细颗粒的粉砂、粘土，沉积速率为0．91—1．24cm／a，近年来砂质物的输入，反映了疏浚等人类活动对该区的影响；外港浅滩砂洲区的沉积速率小于0．4cm／a；潮汐通道中过剩210Pb总量亦明显大于港口的其它区域。

Six sediment cores collected in 1988 in Sanya Harbour, Hainan Island, were analyzed for textural parameters and 210Pb activities. 210Pb dating of sedimentation rates indicated that the rates for fine-grained silts and clays were greatest (0.91-1.24cm/a) in the sediments underlying the tidal and navigation channel in the harbour.lnput of sand, transported into the tidal channel mainIy from the inner harbour region on the ebb tide, was probably due to dredging activities in the harbour. Sedimentation rates in the sandier sediments of the outer harbour region were significantly lower ( <0.4cm/a) compared to those in the tidal channel. 210Pb inventories were much greater in the tidal channel sediments compared to those in other parts of the harbour, indicating that particle-reactive pollutants were probably preferentially deposited in the tidal channel.