摘要
珠江口是典型的亚热带大型河口,全日潮与半日潮相互作用显著,在全球气候变化和高强度人类活动叠加影响下,潮汐系统呈现显著变异特征.本研究针对全日潮(K1、O1)和半日潮(M2、S2)的非线性耦合机制,构建融合分潮振幅比、相对相位解析法与偏度理论的综合评估方法,系统揭示珠江河口正压潮变形的时空特征及其驱动机制.结果表明:潮汐不对称呈现湾口(落潮主导)向湾顶(涨潮主导)的转变特征,其主控机制由外海段的天文分潮组合(O1/K1/M2)主导逐步过渡为上游段的半日分潮(S2、M2)和浅水分潮(M4、MS4)共同作用;2010-2020年间上游分潮振幅衰减、相位增大,潮汐不对称由涨潮主导转为落潮主导,天文分潮相互作用的负不对称性增强,高频分潮的贡献减小;外海海域落潮主导的不对称性趋向减弱,天文-浅水分潮的相互作用表现为正不对称性;受大型基础设施建设、水资源配置工程及海平面上升等因素共同影响,岸线和地形特征均发生了显著改变,进而引发了潮汐动力系统的中长期调整.本研究为理解多尺度扰动下潮汐系统演变规律提供了新的分析框架,对河口综合治理具有重要参考价值.
Abstract
The Zhujiang River Estuary,a typical subtropical large-scale estuary,exhibits significant interactions between diurnal and semi-diurnal tides.Under the combined impacts of global climate change and intensive human activities,its tidal dynamics system has undergone notable variations.This study focuses on the nonlinear coupling mechanisms between diurnal tides(K1,O1)and semi-diurnal tides(M2,S2),developing an integrated evaluation framework that combines constituent amplitude ratios,relative phase analysis,and skewness method.This ap-proach systematically reveals the spatiotemporal characteristics and driving mechanisms of barotropic tidal deform-ation in the Pearl River Estuary.The results include:(1)Tidal asymmetry transitions from ebb dominance at the es-tuary mouth to flood dominance at the upper estuary,with the controlling mechanism shifting from astronomical constituent interactions(O1/K1/M2)in the outer estuary to synergistic effects of semi-diurnal constituents(S2,M2)and shallow-water constituents(M4,MS4)in the upper reaches;(2)From 2010 to 2020,upstream constituents exhib-ited amplitude attenuation and phase increases,leading to a reversal from flood-to-ebb dominated asymmetry.Neg-ative asymmetry induced by astronomical constituent interactions intensified,while the contribution of high-fre-quency constituents decreased;(3)In offshore areas,ebb-dominated asymmetry weakened,with emerging positive asymmetry driven by interactions between astronomical and shallow-water constituents;(4)The tidal dynamics sys-tem of the Pearl River Estuary has undergone significant long-term adaptive adjustments.Due to the combined in-fluences of large-scale infrastructure construction,water resource allocation projects,and sea level rise,coastline and terrain both occur significant changes,which further has driven middle-to-long term adjustment of tidal dynam-ics.This study provides a novel analytical framework for understanding tidal system evolution under multi-scale perturbations and offers crucial insights for integrated estuarine management.
维普
万方数据