海藻产业正在全球范围内发展,以满足未来在食品和燃料方面的资源需求。同时,扩大海底海藻种植对其环境的影响尚不清楚。例如,人们对海底海藻如何影响当地的水动力环境仍然知之甚少,特别是关于湍流,它对养分的运输和可用性比平均流速更重要。这里,我们用模拟海藻Thalli进行了控制良好的水槽实验,可用的,可控,稳定,根据平均流量和湍流速度剖面研究海底海藻冠层对全深度流速的影响。在进行这些实验之前,对自然和模拟海藻thalli之间的流动行为进行了仔细的比较。结果表明,漂浮的海藻thalli产生了表面边界层,并对底部边界层的速度结构产生了深远的影响。更重要的是,一代,海藻thalli地区湍流的生长和消散深深地影响了近床湍流强度和相关床层剪切应力的下游分布。忽略这种湍流变化会导致对海床形态变化的不准确预测。我们的发现表明,扩大海藻种植面积可能会导致下游种植面积的床降解和低扩散的高风险。这些发现为脱底海藻种植的环境影响提供了新的见解,对于优化管理策略以提高海藻生产力,同时最大程度地减少海底不稳定具有重要意义。
The seaweed industry is growing worldwide to meet future resource needs in terms of food and fuel. In the meantime, the impact of expanding off-bottom seaweed cultivation on its environment is unclear. For example, it remains poorly understood how off-bottom seaweeds affect the local hydrodynamic environment, especially concerning turbulence that is more important for nutrient transport and availability than the mean flow velocity. Here, we carried out well-controlled flume experiments with mimic seaweed thalli, which are available, controllable, and stable, to investigate the impact of off-bottom seaweed canopies on whole-depth flow velocities in terms of both mean flow and turbulence velocity profiles. A careful comparison of behavior in the flow between natural and mimic seaweed thalli was made before these experiments. The results show that the floating seaweed thalli generate a surface boundary layer and have a profound impact on the velocity structure in the bottom boundary layer. More importantly, the generation, growth and dissipation of turbulence in the seaweed thalli area deeply affect the downstream distribution of near-bed turbulent strength and associated bed shear stress. Ignoring this turbulent variation would cause inaccurate predictions of morphological changes of the seabed. Our findings suggest that expanding the seaweed cultivation area may cause high risks of bed degradation and low diffusion in the downstream cultivation area. These findings provide novel insights into the environmental influence of off-bottom seaweed cultivation, with important implications for optimizing management strategies to promote seaweed productivity while minimizing seabed destabilization.