Confluence mixing: near-field hydrodynamic controls of the intermodal behavior and their implications for fish ecology

汇流混合：联运行为的近场水动力控制及其对鱼类生态学的影响

• 批准号: 535183985
• 负责人: Dr. Alexander Sukhodolov, Ph.D.
• 金额: --
• 依托单位: Department of Geography and Environmental Management (GEM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/535183985?language=en
• 关键词: Confluence; mixing; near; field; hydrodynamic

River confluences are vital nodal points of fluvial networks and are hotspots of biodiversity in freshwaters ecosystems. Flow structure at confluences is non-uniform and produces complex patterns within mixing interfaces that are characterized by intermodal behavior. The overall mixing rate at confluences is related to the interface pattern, which has a considerable impact on the spread of harmful pollutants, water temperature, sediments and biota. The proposed research aims to improve knowledge of confluence mixing by providing fundamental theory-based insights into the effects of jetting, flow stagnation and river regulation on the intermodal behavior of mixing interfaces and their implications for fish ecology. In this project, complex mixing interfaces generated in shallow, rough-bedded river environments will be assessed directly in the field at a wide range of hydrological conditions using remote sensing and instrumental measurements. Mixing dynamics will be further analyzed by comparing field observations with the theory of intermodal behavior, which will be expanded and validated using results from field-based experiments and numerical simulations. These experiments will also provide information on fish trajectories and fish behavior within mixing interfaces. From these diverse sources of information on mixing, we will develop an agent-based model to simulate fish survival during a passage of harmful toxins. Simulations will be validated using results of a fish survey in a regulated river which ecosystem has recently suffered a mass kill of fish. Theoretical and empirical results of our study will be used to advance predictive methods based on remote sensing of mixing in rivers.

河流汇流区是河流网络的重要节点，也是淡水生态系统生物多样性的热点。汇流处的流动结构是不均匀的，并在混合界面内产生复杂的模式，其特征在于联运行为。汇流处的总体混合率与界面形态有关，界面形态对有害污染物的扩散、水温、沉积物和生物区系有相当大的影响。拟议的研究旨在提高汇流混合的知识，提供基于基础理论的见解喷射，流动停滞和河流调节的影响，混合界面的联运行为及其对鱼类生态的影响。在本项目中，将利用遥感和仪器测量，在广泛的水文条件下，直接在实地评估在浅、粗层河流环境中产生的复杂混合界面。混合动力学将进一步分析比较现场观测与理论的联运行为，这将扩大和验证使用的结果，从现场为基础的实验和数值模拟。这些实验还将提供有关混合界面内鱼类轨迹和鱼类行为的信息。从这些不同来源的信息混合，我们将开发一个基于代理的模型来模拟鱼类生存在有害毒素的通道。模拟将使用在一条受管制的河流，生态系统最近遭受了大规模的鱼类死亡的鱼类调查的结果进行验证。我们的研究的理论和实证结果将用于推进基于遥感的河流混合预测方法。