港珠澳大桥岛隧工程施工海域潮汐调和分析与预报

对港珠澳大桥岛隧工程施工海域2013年的潮汐观测资料进行调和分析,发现该海域潮汐特征为不正规半日潮,以M2分潮为主,其次为K1、O1、S2和P1等分潮;利用调和常数做预报时,分潮个数的选择会在一定程度上影响预报精度。结果表明:分潮由5个增加至25个可以明显改进预报效果,再增加几乎没有改进。选用25个分潮建立调和预报模型预报2014—2016年的潮位,同时对2012年的潮位做了回报,并与实测潮位进行对比。检验结果表明预报潮位与实测潮位趋势一致,大小基本吻合,3a平均的均方根误差为0.16m,可以作为施工潮位窗口的选择依据。对调和预报误差的进一步分析表明,误差主要来源于径流和风的影响,台风带来的风暴增水可以达到1.33m。

Tidal harmonic analysis and prediction in the Hong Kong-Zhuhai-Macao bridge island tunnel project

Based on the harmonic analysis of the tidal observation data in the construction area of Hong KongZhuhai-Macao Bridge Island Tunnel Project in 2013,it is found that the tide in this area is characterized by irregular half-diurnal tide,which is dominated by M2 tide and followed by K1,O1,S2 and P1 tide.The selection of tidal component affects the prediction accuracy to a certain extent.The results show that the prediction accuracy tends to increases when includes tidal components increasing from 5 to 25,while there will be little further improvement by including more tidal components in the prediction.In this paper,25 tidal components are selected to establish a harmonic prediction model to forecast the tidal level from 2014 to 2016,and the results are compared with the tidal level observations.The predicted tidal level shows well consistency with the observations with an averaged root-mean-square error of 0.16 m,which can be used as the basis in selecting the tidal level window for construction.Further analysis shows that the influence of runoff and wind is the main source of the harmonic prediction error,and the water level increase caused by storm surge can reach 1.33 m.