粤西沿岸海域潮汐特征

Tidal characteristics along coast of Western Guangdong Province

对粤西海域水东、湛江、硇州岛、南渡和海安验潮站各1年水位资料进行了调和分析及统计。结果表明:粤西海域北部湛江、水东、硇洲岛、南渡4站主要分潮为M_2、K_1、S_2和O_1,是不规则半日潮;而南部海安站主要分潮为O_1和K_1分潮,是不规则日潮。粤西沿岸各站浅水分潮和平均水位从北到南有减小趋势。在日潮不等方面,粤西沿岸验潮站都存在明显的日潮高、日潮时不等现象。日潮时不等总体上从北到南有降低的趋势,北部湛江、水东和硇州岛涨潮时间比落潮长1~1.5 h,南部南渡和海安两站涨、落潮时相差不大。另外,调和分析和经验公式不再适用于南渡站,南渡河入海口处堤闸工程是主要原因。这为粤西海域环境资源开发、航运活动等提供环境支持和保障。

Based on one year of hourly elevations at the Shuidong,Zhanjiang,the Naozhou Island,Nandu,andHaian tidal stations,we investigated the tidal characteristics by harmonic and statistical analyses.The results showthat the main significant constituents at all stations excepting the Haian station are the M2,K1,S2and O1bands andthat the corresponding tidal type of the four stations is an irregular semidiurnal band in the north area of WesternGuangdong.However,the tide for the Haian station in the south area of Western Guangdong mainly consists of thesignificant constituents O1and K1,whose corresponding tidal type is an irregular diurnal band.Moreover,the shallow-water constituents and mean sea-surface elevations show a decreasing trend from north to south in the west seaof Guangdong.With respect to the diurnal inequality,all the stations exhibit a tidal height difference and an obviouslylarge discrepancy in the tidal hour difference.The mean tidal hour difference between the flood and ebb tides seems toshorten from north to south along the coast of Western Guangdong.The time of the rising tide in the north of WesternGuangdong is roughly1to1.5h longer than that of the falling tide and those in the south of Western Guangdong seemto be nearly equal.In addition,the tidal harmonic analysis and related empirical formula are inexact for the Nandustation,which is mainly due to the bounded bank and sluice gate system on the Nandu River estuary.