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、交通和能源等便利设施的重要来源。河流还支持丰富和动态的生态系统，具有多样化的动植物。虽然对河流的研究已经有几十年的历史，但由于河流本身的复杂性，人们对河流的物理和生物过程的了解仍然有限。鉴于城市化、粗放式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-水力相互作用有良好的了解，以保护我们河流的健康。 在这种背景下，我的研究旨在研究河流中发生的物理水流过程，以及水流结构与水生生物(即鱼类、植物)之间的关系。我的研究计划，在短期内(未来5年)，分为三个轴。轴线1将在明渠中建立河床粗糙度和水流结构之间的基本联系。这项研究将专门研究湍流诱导的二次流在确定床面剪应力和流动阻力中的作用。中轴线2将调查明渠和植被覆盖的树冠中沉积物/溶质运移之间的关系。这将有助于更好地了解河床和岸边的侵蚀/沉积过程和污染物停留时间。中轴线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)后面游动的动态。这项研究的一个主要成果将是为养护和/或恢复目标物种(例如大西洋鲑鱼)首选的精细水生栖息地制定指导方针。 我的研究结果将使工程师和流域/渔业管理者(在加拿大和国外)能够在渠道输送、生态健康和河流栖息地恢复方面做出明智的决定。

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.