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

0538124 Allen-King反应性输运的合作研究：模拟由沉积结构确定的水力和反应性含水层属性之间的空间互相关性反应性物质输运的模型需要表示水力和反应性属性如何在空间中变化，如渗透率（k）和吸附分配系数（Kd）。没有模型还没有纳入这些attributesobserved在以前的，详细的实地研究的共同变化的真实特征。这是反应性输运模型的一个重要局限性。我们假设，在沉积矿床的水力和反应属性之间的空间协变取决于跨单元类型的过渡，就像以前已经显示的水力属性本身的空间变异性。该假设是基于这样的概念，即沉积物侵蚀，运输和沉积包括自然排序沉积物颗粒和创建不同的组成（矿物学）以及晶粒大小的单元类型的过程，我们的假设是基于观察和初步测试使用岩相，k，和Kd数据收集的博登含水层。拟议项目的具体目标是开发和探索一个新的模型，该模型代表了水力和反应属性的空间协变，作为沉积矿床层次结构的函数，以及不同相关尺度上岩性单元内部和之间过渡的概率。该模型将代表在最近的实地研究中观察到的以下关系：（1）点相关性可能是积极的，在一些单位类型和不相关或负在其他。(2)如果相关性存在，它不需要是完美的。(3)与跨单元边界的平移的滞后互相关在跨某些单元类型转换时可以是正的，而跨其他单元类型转换时可以是负的。(4)在沉积结构中，与不同尺度的单元类型相关联的相关性可以有多个相关的整体尺度。这些活动将包括从一个特征明确的现场建立一个适当的数据集，计算模型中代表层次内和层次间关系的术语，并了解这些术语中哪些术语对复合尺度上的互相关有重大贡献，复合尺度是观测羽流扩散的尺度。一旦我们理解了哪些项是重要的，我们将把它们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门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：解释性计算建模研究尚未能够同时再现在受控现场研究中观察到的非理想传输行为的所有方面。这强烈表明，反应性运输的基本方面尚未完全理解。我们在这里重申，缺乏适当的表示之间的协变水力和反应属性的解释反应运输模型是一个显着的局限性，在这样的研究。拟议的项目将提高水力和反应属性的协变的整体理解。它将帮助研究界超越目前用于表示协变的简单化范式，并导致开发一个基于实地观察的替代模型。因此，我们提出的工作将通过改进反应性输运模型中水力和反应性属性的表示，对解释性反应性输运建模产生重要影响。拟议活动产生的更广泛影响：该项目的更广泛影响分为两个一般领域：那些通过直接或间接参与项目来加强学生培训的项目，以及那些通过实现改善的了解沉积含水层内有机污染物的归宿

0538124Allen-KingCollaborative 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