填海工程的海湾动力地貌效应——以芝罘湾为例

Bay dynamic geomorphological effects of reclamation projects:A case study of the Zhifu Bay

港口、人工养殖以及码头建设等填海活动会导致海岸地貌和海域动力环境发生改变,从而影响其海岸带韧性。本文以围填海活动剧烈的芝罘湾为例,基于1977-2022年遥感影像与水深数据,采用空间分析和水动力数值模拟等方法,综合分析了近45年来芝罘湾填海工程下海湾地貌演变与水动力变化情况,结果表明:围填海活动是芝罘湾地貌形态变化以及水动力条件改变的主要原因。①围填海工程导致海湾岸线整体呈现增加的趋势,岸线长度整体增加了10.67 km,岸线结构发生改变,自然岸线保有率持续降低。水深地形变化显著整体冲刷为主,近岸侵蚀严重,1995-2022年均蚀退率达5.4 cm/a。②围填海工程使海湾水动力条件发生改变,导致湾内流速普遍减弱,涨潮时不超过0.2 m/s,流向复杂多变,突堤附近尤为明显,海湾纳潮量呈现持续减小趋势,平均纳潮量整体减少了1.8928×10^(7)m^(3)。研究结果可为芝罘湾海洋生态环境保护与海域资源的合理开发提供科学的对策建议。

Coastal reclamation activities like port construction,aquaculture,and dock development could lead to alterations in coastal morphology and hydrodynamic conditions,consequently having impacts on the resilience of the coastal zones.This paper takes Zhifu Bay,where reclamation activities are intense,as an example,based on remote sensing images and bathymetric data from 1977-2022,comprehensively analyzes the evolution of the geomorphology of the bay and hydrodynamic changes in the Zhifu Bay due to reclamation projects over the past 45years,usingmethodsof spatial analysis and hydrodynamic numerical simulation.The findings affirm that coastal reclamation is the primary driver behind the changes in Zhifu Bay's morphological structure and hydrodynamic conditions.①Coastal reclamation has resulted in an overall increasing of the bay's coastline,with a total shoreline increase of 10.67 km,which has altered the shoreline structure and shrinking natural shoreline.The topography of bathymetry changes significantly,mainly because of wave scouring.Severe nearshore erosion was observed,leading to an average retreat rate of 5.4 cm/a from 1995 to 2022.②Coastal reclamation has altered the hydrodynamic conditions of the bay,resulting in a widespread decrease in flow velocity.During high tides,the velocity does not exceed 0.2 m/s,with complex and variable flow directions,especially near the breakwater.The bay's tidal prism shows a continuous declining trend,with an overall reduction in average tidal prism by 1.8928×10^(7)m^(3).These research findings could privide scientific strategic recommendations for the protection of marine ecological environments and the rational development of maritime resources in Zhifu Bay.