Collaborative Research on Reactive Transport: Modeling Spatial Cross-Correlation between Hydraulic and Reactive Aquifer Attributes as Determined by Sedimentary Architecture

反应输运协作研究：模拟由沉积结构决定的水力和反应含水层属性之间的空间互相关性

• 批准号: 0538037
• 负责人: Robert Ritzi
• 金额: $ 10.14万
• 依托单位: Wright State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2011-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0538037&HistoricalAwards=false
• 关键词: Collaborative; Research; Reactive; Transport; Modeling

0538037RitziCollaborative Research on Reactive Transport:Modeling Spatial Cross-Correlation between Hydraulic and ReactiveAquifer Attributes as Determined by Sedimentary ArchitectureModels for reactive mass transport require a representation of how hydraulic and reactive attributes, such as permeability (k) and the sorption distribution coefficient (Kd), vary in space. No model has yet incorporated the authentic features of the co-variability of these attributesobserved in previous, detailed field studies. This is an important limitation of reactive transport models. We hypothesize that spatial co-variability between hydraulic and reactive attributes in sedimentary deposits depends upon transitions across unit types, much as has been previously shown for spatial variability of hydraulic attributes themselves. The hypothesis is predicated on the concept that sediment erosion, transport and deposition include processes which naturally sort sediment grains and create unit types that differ in composition (mineralogy) as well as grain size.Our hypothesis is based on observations and preliminary testing using lithofacies, k, and Kd data collected for the Borden aquifer. The specific goal of the proposed project is to develop and explore a new model that represents the spatial co-variability of hydraulic and reactive attributes as a function of the hierarchical architecture of sedimentary deposits and the probabilities for transitioning within and between lithologic units across different, relevant scales. The model will represent the following relationships observed in recent field studies: (1)The point-correlation may be positive within some unit types and uncorrelated or negative within others. (2) If correlation exists, it need not be perfect. (3) The lag cross-correlation with translation across unit boundaries may be positive when transitioning across certain unit types and negative across others. (4) There can be multiple, relevant integral scales of correlation associated with the different scale of unit types within the sedimentary architecture. The activities will include developing an appropriate data set from a well-characterized field site, computing theterms of the model which represent relationships within and across hierarchical levels, and gaining an understanding of which of these terms contribute significantly to the cross-correlation at the composite scale, which is the scale at which plume spreading is observed. Once we understand which terms are significant, we will model them as a part of developing the composite model function. The project will involve collaboration among two hydrogeologists, with expertise in geochemistry and geostatistics, and a sedimentologist. Intellectual merit of the proposed activity: Interpretive computational modeling studies have not yet been able to simultaneously reproduce all aspects of nonideal transport behavior that have been observed in controlled field studies. This strongly suggests that fundamental aspects of reactive transport are not yet fully understood. We posit here that lack of proper representation of the co-variability between hydraulic and reactive attributes within theinterpretive reactive transport models is a significant limitation within such studies. The proposed project will enhance overall understanding of co-variabilty of hydraulic and reactive attributes. It will help the research community to move beyond the simplistic paradigm currently used for representing co-variability and lead to development of a well-grounded alternative model built upfrom field observations. Thus, the work we propose will have an important impact on interpretive reactive transport modeling by improving our representation of the hydraulic and reactive attributes within reactive transport models.Broader impacts resulting from the proposed activity: The broader impacts of theproject fall within two general realms: those that enhance student training through direct or indirect participation in the project and those that benefit society through realization of improved understanding of the fate of organic contaminants within sedimentary aquifers

0538037Ritzi 反应输运合作研究：模拟由沉积结构确定的水力和反应含水层属性之间的空间互相关性反应质量输运模型需要表示水力和反应属性，例如渗透率 (k) 和吸附分配系数 (Kd)，空间上有所不同。目前还没有任何模型能够包含在之前详细的实地研究中观察到的这些属性的协变性的真实特征。这是反应性运输模型的一个重要限制。我们假设沉积物中水力属性和反应属性之间的空间共变性取决于单元类型之间的转变，就像之前所显示的水力属性本身的空间变异性一样。该假设基于这样的概念：沉积物侵蚀、迁移和沉积包括自然分类沉积物颗粒并创建成分（矿物学）和颗粒尺寸不同的单元类型的过程。我们的假设基于使用岩相的观察和初步测试， k 和 Kd 为 Borden 含水层收集的数据。该项目的具体目标是开发和探索一种新模型，该模型将水力和反应属性的空间共变性表示为沉积物分层结构的函数，以及跨不同岩性单元内部和岩性单元之间转换的概率。相关尺度。该模型将代表最近实地研究中观察到的以下关系：（1）点相关性在某些单位类型内可能是正相关，而在其他单位类型内可能是不相关或负相关。 (2) 如果存在相关性，则不一定是完美的。 (3) 当跨某些单元类型转换时，与跨单元边界平移的滞后互相关可能为正，而在其他单元类型之间转换时，滞后互相关可能为负。 (4) 沉积构造内可能存在与不同尺度的单元类型相关的多个相关的整体相关尺度。这些活动将包括从充分表征的现场站点开发适当的数据集，计算代表层次内部和层次之间关系的模型术语，并了解这些术语中的哪些对复合的互相关有显着贡献。尺度，即观察到羽流扩散的尺度。一旦我们了解了哪些项是重要的，我们将对它们进行建模，作为开发复合模型函数的一部分。该项目将涉及两名具有地球化学和地质统计学专业知识的水文地质学家和一名沉积学家之间的合作。拟议活动的智力价值：解释性计算模型研究尚未能够同时重现在受控现场研究中观察到的非理想运输行为的所有方面。这强烈表明反应性运输的基本方面尚未完全了解。我们在这里假设，在解释性反应输运模型中缺乏对水力属性和反应属性之间的协变性的正确表示是此类研究的一个重大限制。拟议的项目将增强对水力和反应属性的协变性的整体理解。它将帮助研究界超越目前用于表示协变性的简单范式，并导致开发基于现场观察的基础良好的替代模型。因此，我们提出的工作将通过改进反应性运输模型中水力和反应性属性的表示，对解释性反应性运输模型产生重要影响。拟议活动产生的更广泛的影响：该项目的更广泛影响属于两个一般领域：通过直接或间接参与项目来加强学生培训的项目以及通过更好地了解沉积含水层内有机污染物的命运而造福社会的项目