杭州湾庵东边滩现代发育特征分析

The Modern Evolution Characteristics of Andong Shoal of Hangzhou Bay

由于杭州湾南岸的庵东边滩尺度大,其上游侧、边滩北顶点位置以及下游侧在潮差、潮流、风浪等诸多方面均存在明显不同,加上近十几年来快速人工促淤影响,导致杭州湾庵东边滩现代演变过程未获细致的认识。本文利用杭州湾1959年以来的实测地形资料,对其平面、剖面展布进行时、空的对比分析,认为2000年之后大规模促淤围涂工程加速了庵东边滩到镇海边滩淤涨速率,但是这种影响主要体现在中、高滩以上的区域,-2 m等高线及以上庵东边滩凸岸中部向外淤涨的速度相对最大,边滩的陡坡反映该区域具有典型的横向沉积而非单纯向上淤高的特征,且该区域无论是横向还是纵向均具有沉积速率的不均匀特征,该认识对深化杭州湾南部边滩的现代演变提供了基础。

Andong shoal in the south of Hangzhou Bay the largest tidal estuary of china is very huge, the tidal range, wave, tidal current in the east、north and west side are different obviously, in recent ten years, there were rapid artificial induced siltation. Because of the reasons above, the understanding of the modern evolution of Andong shoal is not enough. In this paper, by the measured terrain data of Hangzhou Bay from year1959, The plane and profile distribution from year 1959 to year 2010 were analysed, The study shown that the massive siltation reclamation engineering had accelerated the progradation rate from the Andong shoal to Zhenhai shoal after 2000, but the impact is mainly reflected in the region above the middle tidal flat. The siltation rate of-2m contour line in the middle of Andong shoal is largest than the other lines . The steep beach reflected the region has typical horizontal deposition rather than simple upward accretion, and the deposition rate of the region both in the horizontal and vertical features are not uniform.This study is helpful for deepening the understanding of the modern evolution of southern Hangzhou Bay Beach.