Louisiana Sea Grant, Louisiana State University, Baton Rouge, LA 70803, USA.
Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, USA.
Sci Rep. 2017 Jan 18;7:40654. doi: 10.1038/srep40654.
Wetland dominated estuaries serve as one of the most productive natural ecosystems through their ecological, economic and cultural services, such as nursery grounds for fisheries, nutrient sequestration, and ecotourism. The ongoing deterioration of wetland ecosystems in many shallow estuaries raises concerns about the contributing erosive processes and their roles in restraining coastal restoration efforts. Given the combination of wetlands and shallow bays as landscape components that determine the function of estuaries, successful restoration strategies require knowledge of wind wave behavior in fetch and depth limited water as a critical design feature. We experimentally evaluate physics of wind wave growth in fetch and depth limited estuaries. We demonstrate that wave growth rate in shallow estuaries is a function of wind fetch to water depth ratio, which helps to develop a new set of parametric wave growth equations. We find that the final stage of wave growth in shallow estuaries can be presented by a product of water depth and wave number, whereby their product approaches 1.363 as either depth or wave energy increases. Suggested wave growth equations and their asymptotic constraints establish the magnitude of wave forces acting on wetland erosion that must be included in ecosystem restoration design.
湿地主导的河口是生态系统生产力最高的自然生态系统之一，它们具有生态、经济和文化服务功能，如渔业育苗场、养分固存和生态旅游。许多浅河口湿地生态系统的持续恶化引起了人们对侵蚀过程及其在限制沿海恢复努力方面的作用的关注。鉴于湿地和浅湾作为决定河口功能的景观组成部分的结合，成功的恢复策略需要了解作为关键设计特征的浅水海湾中波浪的风成行为。我们通过实验评估了浅水区风成波增长的物理特性。我们证明了浅水河口的波浪增长率是风到水深比的函数，这有助于开发一组新的波浪增长方程。我们发现，浅水河口波浪增长的最后阶段可以用水深和波数的乘积来表示，当水深或波能增加时，它们的乘积接近 1.363。建议的波浪增长方程及其渐近约束确定了作用于湿地侵蚀的波浪力的大小，这些力必须包含在生态系统恢复设计中。
