Experimental assessment of Athabasca River cohesive sediment deposition dynamics
Experimental assessment of Athabasca River cohesive sediment deposition dynamics
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DOI：
10.2166/wqrjc.2011.030
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发表时间：
2011-01-01
影响因子：
2
通讯作者：
Jaskot, Christina
中科院分区：
文献类型：
--
作者：
Garcia-Aragon, Juan;Droppo, Ian G.;Jaskot, Christina
多环芳烃（PAHs）的天然来源，并可能从阿萨巴斯卡油砂开发，是阿萨巴斯卡河和阿萨巴斯卡湖三角洲生态系统的关注。为了模拟精细沉积物（和相关的多环芳烃）的传输，重要的是要描述河流系统内的沉积物动力学。絮凝体具有不同的沉降特性相比，单个颗粒。絮凝物沉降行为建模的一个关键方面是絮凝物密度与絮凝物尺寸的数学联系。本文采用旋转环形水槽，测定了阿萨巴斯卡河支流马斯凯格河沉积物在不同剪切条件下的沉降特性。这些沉积物的沉降和絮凝行为的模拟被用来校准密度与絮凝物尺寸模型。絮凝体的尺寸和密度与分形维数F的参数的关系表明，随着直径的增加，絮凝体变得越来越弱。本文进一步阐述了该模型实际应用的建议。沉积试验提供了一个定量测量的相对量的沉积物，可能会通过河流运输给定的流量条件。
Polycyclic aromatic hydrocarbons (PAHs) originating from natural sources, and potentially from the Athabasca Oil Sands development, are of concern for the Athabasca River and Lake Athabasca delta ecosystems. In order to model the transport of fine sediments (and associated PAHs), it is important to describe the sediment dynamics within the river system. Flocs possess different settling characteristics compared to individual particles. A key aspect in modelling floc settling behaviour is the mathematical linkage of the floc density to floc size. In this paper, a rotating annular flume is used to determine the settling characteristics of Muskeg River (a tributary of the Athabasca River) sediments under different shear conditions. Simulations of the settling and flocculation behaviour of these sediments were used to calibrate a density vs. floc size model. A relationship of the parameters relating floc size and density with the fractal dimension F shows that as diameter increases flocs become weaker. Recommendations for the practical application of the model are further formulated in this paper. The deposition tests offer a quantitative measure of the relative amount of sediment that is likely to be transported through the river for given flow conditions.