Three dimensional hydrodynamic and ecological models for water quality problems in Lake Erie

伊利湖水质问题的三维水动力和生态模型

• 批准号: 350475-2007
• 负责人: Lamb, Kevin
• 金额: $ 20.69万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=361478
• 关键词: Three; dimensional; hydrodynamic; ecological; models

Billions of dollars have been spent on the control of nutrient loading to Lake Erie in the U.S. and Canada with the elimination of deep water hypoxia (low oxygen levels) in the central basin of the lake an important goal. In spite of improvements in chlorophyll and phosphorus levels in offshore lake waters, hypoxia appears to have worsened in recent years. There are several hypotheses for the cause of this, including changing climatic conditions, changes in nutrient input from rivers, and the effects of non-native mussels which invaded Lake Erie in the 1980s.Deep water hypoxia occurs in the lower layer of the lake, called the hypolimnion, which lies beneath a thin layer of rapid temperature change with depth called the metalimnion. The metalimnion represents a barrier for the downward flux of oxygen. In recent years it has become appreciated that breaking internal waves in the metalimnion are an important mechanism for this downward flux. This is one of several ways in which physical processes in the lake have an impact on biological and chemical processes.In this research data will be used to validate a lake-scale hydrodynamic-biogeochemical numerical model which will then be used to demonstrate the implications of current hypotheses and to explore the possible implications of future climate change scenarios. In order to elucidate the role of breaking internal waves in the thermocline a field program will be conducted to obtain data with high temporal and spatial resolution. This will be the first such study in Lake Erie. Physical, chemical and biological measurements will be made enabling links between various processes to be made and to establish their role in the formation of hypoxic water. Lake-scale and high-resolution numerical simulations will be undertaken to provide a fuller picture of these important processes. This research will result in a synthesized picture of the role of large and small scale processes in the formation of deep water hypoxia and provide useful tools for the future management of this important lake, tools which can also be applied to other lakes.

在美国和加拿大，数十亿美元用于控制伊利湖的营养负荷，消除湖泊中央盆地的深水缺氧（低氧水平）是一个重要目标。尽管近海湖泊沃茨的叶绿素和磷水平有所改善，但近年来缺氧似乎有所恶化。有几种假说解释了这一现象的原因，包括气候条件的变化，河流营养物质输入的变化，以及20世纪80年代入侵伊利湖的非本地贻贝的影响。深水缺氧发生在湖泊的下层，称为低层，位于一层温度随深度迅速变化的薄层之下，称为变层。超水层是氧气向下流动的屏障。近年来，人们已经认识到，打破内波的变水层是一个重要的机制，这种向下的流量。这是湖泊中的物理过程对生物和化学过程产生影响的几种方式之一，在这项研究中，数据将被用来验证一个湖泊尺度的水动力-地球化学数值模型，然后将被用来证明目前的假设的影响，并探讨未来气候变化情景的可能影响。为了阐明温跃层中破裂内波的作用，将进行一项实地方案，以获得具有高时间和空间分辨率的数据。这将是在伊利湖进行的首次此类研究。将进行物理、化学和生物测量，以便建立各种过程之间的联系，并确定它们在低氧水形成中的作用。将进行湖泊规模和高分辨率的数值模拟，以便更全面地了解这些重要过程。这项研究将导致在形成深水缺氧的大，小尺度过程中的作用的综合图片，并提供有用的工具，为这个重要的湖泊，工具，也可以应用于其他湖泊的未来管理。