珠江三角洲径潮相互作用下潮能的传播和衰减

摘要

Due to the interaction of runoff and tide,the energy flux of delta's channels contains the runoff energy and the tidal energy.Based on the data of water level and flow measurement in the Pearl River Delta,an interac-tion model between the runoff and the tide was established to calculate the M2 ,K1 tidal energy and the tidal energy of high tidal frequency without the signal of river flow.The results showed that about 51.2% of the tidal energy through the Humen into delta,and the tidal energy through Yamen,Jiaomen,Modaomen accounted for about 37%.For the friction effect of topographical and runoff,148.33 MW energy in the delta is loss.Tidal energy propagated as the convergent type or divergent type along the delta and damped.The unit kinetic energy along the path decay quicker than the tidal potential energy,and semidiurnal tidal energy can decay greater than that of diur-nal tide,which is more significant in the upper delta.For the influence of the morphology of Humen-Shiziyang outlet,the attenuation of M2 tidal amplitude (or energy)is the smallest,even the M2 tidal energy increase approxi-mately 0.77% from Humen to Sishengwei.In the two channels system including Humen-Shiziyang outlet and Yamen outlet to Shizui of Tanjiang ,the total tidal energy attenuation is greater than the attenuation of unit tidal energy for the tide energy diverge into different branches.But the total tidal energy attenuation is greater than the attenuation of unit tidal energy in the west river delta for the tide energy from Modaom,Jitimen,Hutiaomen and Yamen converge.The tides from Hengmen,Hongqimen and Jiaomen converged and diverged in the middle delta, and the total kinetic energy,M2 tidal energy,K1 tidal energy is less than the tidal potential energy.The tidal po-tential energy of high frequency including D3 and D4 constituents has increased along the channel.%因径流潮汐相互作用，三角洲各水道的能通量包含径流引起的净通量及潮汐引起的潮能通量。本文利用珠江三角洲多断面实测水位及流量的同步测量数据，建立基于径潮耦合的调和分析模型，剥离径流信号，计算出各站的总潮能及 M2、K1及高频浅水分潮的潮能，对珠江三角洲潮能的沿程传播及衰减进行研究。结果表明，通过虎门进入珠江三角洲的潮波能量约占51．2％，而通过崖门、蕉门、磨刀门传入三角洲的潮能约占37％；同时，因地形摩擦、径流耗能效应，三角洲各水道的总能量损耗为148．33 MW。潮波能量按汇聚型和分散型两大类型沿三角洲不同位置传播并沿程衰减。虎门狮子洋及珠江正干、崖门至潭江石咀两大水道体系，其潮能沿程分散传入不同汊道，断面总潮能的衰减幅度大于单宽潮能通量的衰减，单宽潮动能沿程平均衰减速率大于潮势能，半日分潮的潮能衰减速率大于全日分潮。虎门狮子洋因其形态影响，M2分潮振幅（或势能）的衰减最小，虎门至泗盛围段增加，平均每千米约增加0．77％。西四口门潮能汇聚于西海水道天河断面，总潮能的衰减速率小于磨刀门水道单宽潮能衰减速率。沿横门、洪奇门、蕉门进入的潮波多次交汇、分散，自横门至小榄、南华，南沙至海尾、荣奇，其单宽潮动能及 M2、K1分潮动能的衰减速率小于潮势能，高频分潮势能沿程增加。