2002—2020年深圳湾河床冲淤特性及驱动机制  

Riverbed erosion-deposition dynamics and driving mechanisms in Shenzhen Bay,2002-2020

作　　者：康远泰 卢陈 高时友 吴尧 KANG Yuantai;LU Chen;GAO Shiyou;WU Yao(Pearl River Water Resources Research Institute,Pearl River Water Resources Commission,Guangzhou 510611,China;Key Laboratory of the Pearl River Regulation and Protection of Ministry of Water Resources,Guangzhou 510611,China)

机构地区：[1]珠江水利委员会珠江水利科学研究院,广东广州510611 [2]水利部珠江河口治理与保护重点实验室,广东广州510611

出　　处：《水科学进展》2024年第6期947-959,共13页Advances in Water Science

基　　金：国家重点研发计划资助项目(2023YFC3007900);中国水利水电科学研究院水利部泥沙科学与北方河流治理重点实验室开放基金(IWHR-SEDI-202105)。

摘　　要：明晰海湾冲淤变化规律与演变模式对城市化河口湾的开发利用具有重要意义。以深圳湾为研究对象,基于2002—2020年深圳湾高程数据,采用经验正交函数(EOF)、冲淤变化定量评估等方法开展年际冲淤变化特征、淤积模式研究,探讨冲淤变化影响因素。结果表明:深圳湾整体成淤积态势,内湾年淤积量为67.54万m^(3)(平均淤积厚度为1.5 cm/a),外湾年淤积量为35.22万m^(3)(平均淤积厚度为0.98 cm/a);深槽-浅滩界面区域淤积是内湾的主要演变模式,但随着潮滩淤长,该模式逐渐减弱趋于平衡,外湾以深槽区域淤积为主;内湾南槽逐渐萎缩,由“宽窄型”向“等宽型”转变,伴随着喇叭口顶点位置西移、河控范围向下游延伸;潮流作用下的外界(伶仃洋)来沙是深圳湾淤积的主要来源,潮汐动力为主导的动力地貌相互作用是深圳湾演变的驱动机制,而极端天气下的伶仃洋动力格局显著影响深圳湾的冲淤变化。深圳湾治理须顺应以潮流为主导的外界来沙淤积模式。Understanding erosion-deposition dynamics in coastal bays is crucial for the sustainable development and management of urban estuaries.This study investigates the interannual erosion–deposition dynamics in Shenzhen Bay from 2002 to 2020.Field-measured topographic data alongside empirical orthogonal function(EOF)analysis and quantitative sediment assessment were used to identify the primary factors influencing these patterns.The findings reveal that Shenzhen Bay experiences a general trend of deposition,with the inner and outer bays undergoing an annual sediment accumulation of 675400 m^(3)(averaging 1.5 cm/a)and 352200 m^(3)(averaging 0.98 cm/a),respectively.In the inner bay,deposition primarily develops at the boundary between deep channels and shallow flats;however,this pattern gradually declines toward equilibrium as sediments accumulate in the tidal flats.In contrast,the outer bay is characterized by sediment accumulation in deep channel areas.The south channel in the inner bay continues to narrow,shifting from a“wide-narrow”profile to a“uniform-width”profile.This shift is accompanied by the channel apex moving leftward and a downstream extension of the river-dominated area.Tidal currents drive external sediment inputs from Lingdingyang Bay,which represents the principal source of deposition in Shenzhen Bay.The evolution of Shenzhen Bay is primarily shaped by morphodynamic interactions that are dominated by tidal forces,and its erosion-deposition dynamics are significantly influenced by the dynamics of Lingdingyang Bay during extreme weather events.Thus,the management of Shenzhen Bay should be tailored to the erosion-deposition dynamics that are dominated by external sediment inputs and primarily driven by tidal currents.

关 键 词：冲淤变化 淤积模式 年际地形 影响因素 深圳湾 

分 类 号：TV14[水利工程—水力学及河流动力学]