Computational Modelling of the Impacts of Saltmarsh Management Interventions on Hydrodynamics of a Small Macro-Tidal Estuary
Computational Modelling of the Impacts of Saltmarsh Management Interventions on Hydrodynamics of a Small Macro-Tidal Estuary
复制标题
盐沼管理干预措施对小型宏观潮汐河口水动力影响的计算模型
DOI：
10.3390/jmse8050373
复制
发表时间：
2020
影响因子：
2.9
通讯作者：
H. Karunarathna
中科院分区：
文献类型：
--
作者：
W. G. Bennett;T. V. van Veelen;T. P. Fairchild;J. Griffin;H. Karunarathna
盐沼被认为是天然的海岸防御。然而，由于很大的背景依赖性，有很多讨论他们在提供海岸保护的有效性和额外的海岸防御干预的必要性。在威尔士西南部的大潮汐Taf河口被选为本文的案例研究调查的影响，人为的海防干预措施，如建设硬防御，管理调整，改变土地利用的盐沼河口复杂的水动力。耦合流波植被模型，开发使用Delft 3D沿海建模软件，被使用。波浪和电流衰减作用的盐沼在两个对比的风暴条件下进行建模，有和没有盐沼管理干预。研究表明，某些盐沼管理干预措施可以对河口的水动力产生广泛的影响。通过允许牲畜广泛放牧盐沼来改变土地使用被认为对波衰减影响最大，与无干预情景相比，沼泽上的波高几乎翻了一番。另一方面，有管理的重新调整对潮流有重大影响，在某些地方，潮流达到0.5米/秒。河口水动力学的变化可能会导致洪水和侵蚀的不利影响，这强调了了解本地化的人为海岸管理干预对整个河口系统的影响的重要性。
Saltmarshes are considered as natural coastal defences. However, owing to the large context dependency, there is much discussion over their effectiveness in providing coastal protection and the necessity of additional coastal defence interventions. The macro-tidal Taf Estuary in south-west Wales was chosen as the case study in this paper to investigate the effects of anthropogenic coastal defence interventions such as construction of hard defences, managed realignment, and altering land use of the saltmarshes on the complex hydrodynamics of the estuary. A coupled flow–wave–vegetation model, developed using the Delft3D coastal modelling software, was used. The wave and current attenuation role of saltmarshes during two contrasting storm conditions was modelled, with and without saltmarsh management interventions. The study reveals that certain saltmarsh management interventions can have widespread impacts on the hydrodynamics of the estuary. Altering the land use by allowing extensive grazing of saltmarsh by livestock was found to have the largest impact on wave attenuation, where wave heights on the marsh almost doubled when compared with the no-intervention scenario. On the other hand, managed realignment has a significant impact on tidal currents, where tidal currents reached 0.5 m/s at certain locations. Changes in estuarine hydrodynamics can lead to undesired impacts on flooding and erosion, which stresses the importance of understanding the effects of localized anthropogenic coastal management interventions on the entire estuarine system.