A morphodynamic model to simulate the seasonal closure of tidal inlets
A morphodynamic model to simulate the seasonal closure of tidal inlets
复制标题
模拟潮汐入口季节性关闭的形态动力学模型
DOI：
10.1016/s0378-3839(99)00008-3
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
G. Masselink
中科院分区：
文献类型：
--
作者：
R.W.M.R.J.B. Ranasinghe;C. Pattiaratchi;G. Masselink
季节性开放的潮汐入口通常出现在微潮、波浪主导的沿海环境中，那里的水流和波浪气候具有强烈的季节性变化。由于入口处形成沙洲，这些入口每年都会有几个月与海洋关闭。这些入海口每年都会关闭，从而限制船只进入海洋，还可能导致与入海口相连的河口/泻湖水质恶化。由于这些河口/泻湖通常用作港口或娱乐设施，因此人们越来越关注保持入口永久开放。能够模拟入口关闭的基于过程的数值模型对于识别控制入口关闭的自然过程非常有价值。更进一步，这种类型的模型还可用于确定任何拟议的工程解决方案的效果，以保持邻近海滩的入口开放。本研究开发了一种能够模拟入口季节性关闭的形态动力学模型，其中包括沿岸（LST）和跨岸运输（CST）过程。该模型在两个理想场景中的应用表明，当 LST 率较低时，跨岸过程控制入口行为。 Dean 的标准 [Dean, R.G., 1973。冲浪区沙粒输送的启发式模型。过程。会议。关于英语。悉尼冲浪区动力学，第 208-214 页。] 海上运输表明，对于较小的海上波浪入射角，当海上波浪陡度 (Ho/Lo) 小于临界波浪陡度 (Ho/Lo) 临界时，陆上运输有助于入口关闭，而当 (Ho/Lo) 大于 (Ho/Lo) 临界时，海上运输有助于保持入口打开。当近海波浪入射角较大时，当 (Ho/Lo) 远大于 (Ho/Lo) 临界值时，LST 是导致入口关闭的主要过程。
Seasonally open tidal inlets usually occur in microtidal, wave-dominated coastal environments where strong seasonal variations of streamflow and wave climate are experienced. These inlets are closed to the ocean for a number of months every year due to the formation of sand bars across their entrances. The annual closure of these inlets inhibits ocean access for boats and could also cause deterioration of water quality in the estuary/lagoon connected to the inlet. As these estuaries/lagoons are commonly used as harbours or recreational facilities there is increased interest in keeping the inlets permanently open. A process-based numerical model capable of simulating inlet closure is invaluable in terms of identifying the natural processes governing inlet closure. As a further step, this type of model could also be used to determine the effect of any proposed engineering solutions to keep the inlet open on the adjacent beaches. A morphodynamic model capable of simulating the seasonal closure of inlets, which includes both longshore (LST) and cross-shore transport (CST) processes, was developed in this study. Application of the model to two idealised scenarios indicated that cross-shore processes govern inlet behaviour when LST rates were low. The Dean's criterion [Dean, R.G., 1973. Heuristic models of sand transport in the surf zone. Proc. Conf. on Eng. Dynamics in the Surf Zone, Sydney, pp. 208–214.] for on–offshore transport was employed to show that, for small offshore wave incidence angles, onshore transport aided inlet closure when the offshore wave steepness (Ho/Lo) was less than the critical wave steepness (Ho/Lo)crit, while offshore transport helped to keep the inlet open when (Ho/Lo) was greater than (Ho/Lo)crit. LST was found to be the dominant process leading to inlet closure when (Ho/Lo) was much larger than (Ho/Lo)critor when the offshore wave incidence angle was large.