杭州湾枯季水沙若干特征分析  

Some characteristics of flow and sediment in dry season in the Hangzhou Bay

作　　者：葛灿 潘存鸿[1] 张沈阳[1] GE Can;PAN Cunhong;ZHANG Shenyang(Zhejiang Provincial Key Laboratory of Estuary and Coast, Zhejiang Institute of Hydraulics and Estuary, Hangzhou 310020, China;State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China)

机构地区：[1]浙江省水利河口研究院浙江省河口海岸重点实验室,浙江杭州310020 [2]华东师范大学河口海岸学国家重点实验室,上海200241

出　　处：《海洋工程》2021年第2期70-79,共10页The Ocean Engineering

基　　金：国家重点研发计划项目(2018YFC0407506);浙江省自然科学基金项目(LQ19D060001);浙江省省属科研院所扶持经费项目(杭州湾演变及河口形态研究);国家自然科学基金项目(51779228);中国博士后科学基金项目(2019M652147)。

摘　　要：根据2014年1月及2017年2月杭州湾大、小潮水沙资料,计算了流速、含沙量、单宽潮量、单宽输沙量,进而分析了潮周期断面净潮量、净输沙量和区域冲淤分布。研究发现杭州湾涨、落潮平均流速比值整体较20世纪八九十年代增大,绝大部分区域大于1.0,涨潮流相对增强,澉浦南岸和金山北岸尤为显著。含沙量平面上分布澉浦、杭州湾南岸两个高值区(大潮大于3 kg/m^(3),小潮大于1.3 kg/m^(3))以及北岸湾口至乍浦之间的低值区(大潮小于2 kg/m^(3),小潮小于0.9 kg/m^(3)),随潮汛变化显著,最大含沙量浓度通常滞后于急流时刻。各测站涨、落潮量和输沙量呈现“大涨大落”和“大进大出”的特征,造成杭州湾短时间尺度内的“大冲大淤”。大潮两涨两落金山与乍浦、乍浦与澉浦之间区域净输沙量可达几千万吨,净冲淤则在几百万吨。Based on the data of water and sediment in the Hangzhou Bay in January 2014 and February 2017,the flow velocity,sediment concentration,tidal and sediment discharge of unit width during the spring and neap tide were calculated,and then the net tide,sediment discharges and distribution of erosion and deposition were analyzed.The results show that the velocity ratios of flood tide versus ebb tide in the Hangzhou Bay were higher than those in 1980s and 1990s,exceeding 1.0 in most areas.That indicates the relative enhancement of flood tide,especially in the southern of Ganpu and northern of Jinshan sections.There are two high sediment concentration regions(Ganpu and south Hangzhou Bay,>3 kg/m^(3)in spring tide and>1.3 kg/m^(3)in neap tide)and one low sediment concentration region(north Hangzhou Bay from the mouth to Zhapu,<2 kg/m^(3)in spring tide and<0.9 kg/m^(3)in neap tide).Mean sediment concentration changes remarkably with the flood-ebb tidal cycle and the occurrence of maximum sediment concentration tends to lag behind peak tidal velocity.The dramatic tidal range and sediment runoff result in quick erosion and deposition in the Hangzhou Bay.Within two tidal cycles,the net sediment transport amount reaches up to tens of million tons between Jinshan and Zhapu,and between Zhapu and Ganpu,and the net erosion or deposition can be millions of tons of sediment.

关 键 词：水沙特征 流速比 水沙通量 冲淤分布 杭州湾 

分 类 号：TV148[水利工程—水力学及河流动力学]