瓯江口水文泥沙特征分析

在大量实测资料的基础上,对瓯江口海区的地貌特征、河道径流特征、河道输沙特征、潮汐特征、潮流特征、余流特征、波浪特征、含沙量特征、泥沙来源、盐度特征、悬沙粒径和底质粒径特征、瓯江南北口的分流和分沙特征、中水道和北水道的分流和分沙特征进行了分析,根据实测资料分析得到了瓯江口挟沙力公式,得到了平衡水深公式,为瓯江河口的工程开发建设和科学研究提供了基础资料。主要研究成果表明:(1)瓯江口的潮汐属正规半日潮类型,平均潮差在4 m以上,属强潮河口;(2)潮流属正规浅海半日潮流类型,呈往复流动,潮流动力强;(3)瓯江为少沙河流,多年平均年悬移质输沙量为205.1万t;(4)瓯江南北口的平均涨潮分流比为21%和79%,落潮平均分流比为26%和74%;(5)瓯江南北口的平均涨潮分沙比为20%和80%,落潮平均分流沙比为22%和78%。

Hydrographic and sediment analyses of the Oujiang estuary

On the basis of abundant field measured data,analyses and studies are carried out on the characteristics of landform and topography,river runoff,river sediment transport,tide,tidal current,residual current,sediment content in water,sediment sources,salinity,grain size of suspended sediment,grain size of bed-load sediment,the distribution of water and sediment in the south branch and north branch of the Oujiang river and the distribution of water and sediment in the Middle waterway and the North waterway in the sea area of the Oujiang estuary.Sediment carrying capacity and equilibrium water depth formula are gained through analyses of field data.Basic data can be provided for the exploitation & construction projects and science studies in the Oujiang estuary.Some main study results are as follows:(1)Tide in the Oujiang estuary is normal semidiurnal tide with average tidal range over 4 m,and the tide is strong in the Oujiang estuary.(2)Tidal current in the Oujiang estuary belongs to shallow sea normal semidiurnal tide current which is very strong and assumes alternating current.(3)The Oujiang river lacks in sediment,whose yearly average sediment transport amount is only approximately 2.051 million tons.(4)The average water diversion ratio of south branch and north branch of the Oujiang river during flood tide is 21% and 79%,and 26% and 74% during ebb tide.(5)The average sediment diversion ratio of south branch and north branch of the Oujiang river during flood tide is 20% and 80%,and 22% and 78% during ebb tide.