Extracting sea level residual in tidally dominated estuarine environments
Extracting sea level residual in tidally dominated estuarine environments
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DOI：
10.1007/s10236-012-0543-7
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发表时间：
2012-07-01
期刊：
影响因子：
2.3
通讯作者：
Souza, Alejandro J.
中科院分区：
文献类型：
--
作者：
Brown, Jennifer M.;Bolanos, Rodolfo;Souza, Alejandro J.
海平面由平均水位、潮汐高程和剩余高程组成。对造成最高水位的原因的了解往往是沿海管理的关键。然而，从模型和观测高程中提取水位偏差(残差)的不同方法可能会得出不同的结果。英格兰西北部的迪河口是一个经历周期性层结的大潮汐河口。这里使用它来演示提取剩余水位的方法，以响应以下交互过程：潮汐、河流诱导的分层和流动、气象和海浪。利用建模技术，研究了不同物理过程的相互作用和贡献。经典的调和潮汐分析、模型模拟和滤波技术已被用于短期(大约一个月)记录的总高程的“去潮汐”。每种技术都给出了不同的结果，强调了为所需研究选择正确方法的必要性。对残差分量的分析表明，所有产生残差的过程都与潮汐相互作用，产生半日的残差分量。有人建议，建模方法使潮汐相互作用的全部影响保留在残差中，而调和潮汐分析(部分)修正和滤波方法(完全)去除残差中的这一部分。本文提出的分析方法及其对残留物的影响也适用于其他研究地点。然而，当专门应用于Dee河口时，外部涌浪被发现是造成总残留的主要因素，而当地风和层结的影响是次要的。
Sea level comprises a mean level, tidal elevation and a residual elevation. Knowledge of what causes maximum water levels is often key in coastal management. However, different methods to extract deviations in water level (residuals) from modelled and observed elevation can give different results. The Dee Estuary, northwest England is a macrotidal estuary that undergoes periodic stratification. It is used here to demonstrate methods to extract the residual water level in response to the following interactive processes: tidal, river-induced stratification and flow, meteorology and waves. Using modelling techniques, the interaction and contribution of different physical processes are investigated. Classical harmonic tidal analysis, model simulations and filtering techniques have been used to "de-tide" the total elevation for short-term (approximately month long) records. Each technique gives a different result highlighting the need to select the correct method for a required study. Analysis of the residual components demonstrates that all processes inducing residuals interact with the tide generating a semi-diurnal residual component. It is suggested that modelling methods enable the full effect of tidal interaction to remain in the residual, whilst harmonic tidal analysis (partly) modify and filtering methods (fully) remove this component of the residual. The analysis methods presented and their influences on the resultant residual are applicable to other study sites. However, when applied specifically to the mouth of the Dee Estuary, the external surge is found to be the main contributor to the total residual, whilst local wind and stratification effects are of secondary importance.