中国南海北部海图深度基准面换算关系的研究

中国南海北部不同时期的海图采用的深度基准面不一样,深度基准面的多样性使的不同时期所计算的深度基准面数值不具有统一性,无法充分利用诸多历史海图资料,有必要了解历史海图深度基准面之间的关系。针对中国南海北部,利用多年实测潮位资料进行调和分析并根据调和常数计算验潮站的深度基准面,获得中国南海北部14个验潮站的深度基准面值,探讨了不同深度基准面之间的换算关系,研究表明最低低潮面不适合日潮海区,理论最低潮面与略最低潮面之间平均间距为18cm,理论最低潮面与最低天文潮面除厦门、三亚外两者平均差距达到1.88cm,具有近似一致性。

Conversion Relationship Between Depth Datums in the Northern South China Sea

In different periods,various depth datums are adopted in charts in the northern South China Sea.Thevariation leads to the disunity of the calculative depth datum values.It is unable to make full use of historicalchart data,and it is necessary for us to know more about the relationship between the historical depth datums.For some areas in the northern South China Sea,including the Pearl River Delta,Macao,Guangzhou Bay and theEast Port and so on,the depth datums are sorted out in this paper.Years of measured data are used for tidalharmonic analysis.Based on the harmonic constants,the depth datums in 1 4.tidal gauge stations in the researchareas are acquired.The conversion relationship between different depth datums is discussed.The research showsthat the lowest low water is not suitable for the diurnal tidal sea areas.The average distance between thetheoretical depth datum and the lower low water is 1 8.cm,and the average distance between the theoretical depthdatum and the lowest astronomical tide level is 1.8 8.cm,except Xiamen and Sanya.They have an approximateconsistency.