Turbulent flow structure and flow-biota interactions in open channels

世界各地的河流一直是人类活动的中心。在加拿大，河流是饮用水、食物、交通和能源等生活设施的重要来源。河流还支持丰富和动态的生态系统，具有多样的植物群和动物群。虽然河流已经研究了几十年，但由于其内在的复杂性，对其物理和生物过程的理解仍然有限。鉴于城市化、粗放型农业和气候变化带来的压力越来越大，需要对河流过程和生态-水力相互作用有充分的了解，以保护我们河流的健康。 在这种情况下，我的研究旨在调查河流中发生的物理流动过程以及流动结构与水生生物群之间的关系（即，鱼、植物）。我的研究计划，在短期内（未来5年），分为沿着3轴。轴1将建立河床糙率和明渠水流结构之间的基本联系。这项研究将专门调查在确定床面剪切应力和流动阻力的作用，由粘性引起的二次流。轴2将研究明渠中的沉积物/溶质输运与植被冠层之间的关系。这将导致更好地了解河床和河岸侵蚀/沉积过程和污染物停留时间。轴3将调查鱼类的水力栖息地偏好和鱼类在水下障碍物（例如，巨石）。这项研究的一个主要成果将是制定保护和/或恢复目标物种首选的精细尺度水力栖息地的指导方针（例如，大西洋鲑鱼）。 从我的研究结果将使工程师和流域/渔业管理人员（在加拿大和国外）作出明智的决定，在河流中的渠道运输，生态健康和栖息地恢复。

Rivers around the world have always been at the center of human activity. In Canada, rivers are an essential source of amenities such as drinking water, food, transportation, and energy. Rivers also support rich and dynamic ecosystems, with a diverse flora and fauna. Although rivers have been studied for decades, the understanding of their physical and biological processes is still limited due to their intrinsic complexity. Given the growing pressure from urbanization, extensive agriculture, and climate change, a sound understanding of river processes and ecology-hydraulic interactions is needed to preserve the health of our rivers. In this context, my research aims to investigate physical flow processes occurring in rivers and the relationships between flow structure and aquatic biota (i.e., fish, plants). My research program, in the short-term (next 5 years), is divided along 3 axes. Axis 1 will establish fundamental links between bed roughness and flow structure in open channels. This research will specifically investigate the role of turbulence-induced secondary currents in determining bed shear stress and flow resistance. Axis 2 will investigate the relationships between sediment/solute transport in open channels and vegetated canopies. This will lead to a better understanding of riverbed and bank erosional/depositional processes and pollutant residence times. Axis 3 will investigate fish hydraulic habitat preference and the dynamics of fish swimming behind submerged obstacles (e.g., boulders). A major outcome of this research will be to develop guidelines for the conservation and/or restoration of the preferred fine-scale hydraulic habitat of the target species (e.g., Atlantic salmon). The results from my research will allow engineers and watershed/fisheries managers (in Canada and abroad) to make informed decisions regarding channel conveyance, ecological health, and habitat restoration in rivers.