School of Engineering, University of Plymouth, Plymouth PL4 8AA, UK.
Andalusian Institute for Earth System Research, University of Granada, Avda. del Mediterráneo, s/n, Granada 18006, Spain.
Sci Total Environ. 2018 Sep 15;636:1541-1552. doi: 10.1016/j.scitotenv.2018.04.333. Epub 2018 May 9.
The impacts of wave farms (arrays of wave energy converters, or WECs) on the nearshore must be fully understood for wave technology to develop and thus contribute to a sustainable, carbon-free energy mix in the near future. The objective of this work is to investigate the role played by the farm layout on the wave propagation patterns leewards and the implications for longshore sediment transport (LST) and shoreline evolution on a gravel-dominated deltaic coast. Changes in wave propagation in four scenarios, corresponding to as many wave farm layouts, are computed by means of a spectral numerical model (Delft3D-WAVE) under (i) low-energy and storm conditions, and (ii) westerly and easterly waves - the two prevailing wave directions. On this basis, sediment transport rates are computed and changes in the shoreline position assessed using a one-line model. To quantify the impact of the wave farm on the nearshore wave conditions, sediment transport and shoreline, we define three ad hoc indicators: the non-dimensional wave height reduction, the non-dimensional LST rate reduction and the non-dimensional shoreline advance. Significant wave heights decrease in the lee of the wave farm, with the consequent reduction in LST rates. As a result, the dry beach area increases in every scenario under both westerly and easterly waves. We find that case studies with the WECs arranged on fewer rows but covering a greater stretch of coastline provide better coastal protection. These results confirm that wave farms can be used not only to generate carbon-free energy but also to protect gravel-dominated coasts.
为了推动波浪能技术的发展，进而在不久的将来为可持续的无碳能源组合做出贡献，必须充分了解波浪能场（波浪能转换器阵列，或 WECs）对近岸地区的影响。本工作的目的是研究农场布局对顺风方向波浪传播模式的影响，以及对多砾石主导的三角洲海岸的沿岸泥沙输运（LST）和海岸线演化的影响。通过谱数值模型（Delft3D-WAVE）计算了四个场景（对应于四种 WEC 布局）中的波浪传播变化，这些场景包括（i）低能量和风暴条件，以及（ii）西风和东风波 - 这两种主要的波浪方向。在此基础上，使用一线模型计算泥沙输运率和海岸线位置的变化。为了量化波浪能场对近岸波浪条件、泥沙输运和海岸线的影响，我们定义了三个特定的指标：无量纲波高降低率、无量纲泥沙输运率降低率和无量纲海岸线推进率。在顺风方向，波浪能场后面的波浪显著减弱，随之而来的是泥沙输运率的降低。因此，在西风和东风条件下，每个场景中的干滩面积都增加了。我们发现，WECs 布置在较少行但覆盖更长海岸线的案例研究提供了更好的海岸保护。这些结果证实，波浪能场不仅可以用于产生无碳能源，还可以用于保护多砾石主导的海岸。
