浙南淤泥质海岸冲淤变化和泥沙运动

VARIATION OF EROSION AND SILTATION AND SEDIMENTATION OF THE MUDDY COAST IN THE SOUTHERN ZHEJIANG PROVINCE

本文研究了浙南北起瓯江口,南至平阳咀淤泥质海岸的冲淤演变过程,指出,岸滩每年以10—20米的速度向海淤涨。为该地区海涂的开发提供了依据。

The muddy coast of the southern Zhejiang Province belongs to deposited coastal segment. The source of sediments is quite in abundance.It is supplied by the Oujiang, the Fiyuenjiang and the Aujiang Rivers.In addition, it is also supplied by the littoral current. In the recent 30 years, the mean progra-dation-rate of the shores and beaches toward the sea reaches about 20-30m per year. The vertical distribution of the sediments also proves that the sediments of the offshroe facies of. the modern intertidal zone developed on the basis of the shallow sea facies of the prime subtidal zone.The changes of the shores and beaches and erosion and accretion of this region are very complicate from hydrological and sedimental points of view. In general, there is a tendency of deposition above the medium tidal level, but below that level, the sediments are not deposited easily because the hydrody-namic forces are relatively string and also because of the littoral current.