Modeling Hierarchical Aquifer Architecture From Centimeter to Kilometer Scales

模拟从厘米到公里尺度的分层含水层结构

• 批准号: 0510819
• 负责人: Robert Ritzi
• 金额: --
• 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: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510819&HistoricalAwards=false
• 关键词: Modeling; Hierarchical; Aquifer; Architecture; Centimeter

0510819RitziComplexity and uncertainty in ground water flow and transport are related to heterogeneity in the hydraulic properties of natural porous media. In deposits of sediment this heterogeneity is related to the sedimentary architecture, of which the important aspects are the proportions, geometry, and juxtapositioning relationships of sedimentary units. These are units created at different spatial scales under various processes of deposition and erosion and organized within a hierarchical framework. Realistic representations of aquifer architecture within hydrogeologic models must be achieved because the geologic structures reduce entropy in hydraulic properties from the maximally disordered state. At the same time, these structures can create greater entropy in transport statistics compared to those from a maximum entropy spatial field (e.g., models containing interconnected gravel units within a lower permeability background have greater variance in mass residence time statistics than models containing random, unconnected gravel patches).A digital representation of a sedimentary deposit will be created with realistic architecture from the scale of centimeters up to the scale of kilometers. A model with this range of scales is unprecedented. The digital deposit will represent the hierarchical sedimentary architecture of fluvial braid-belt deposits, common in both aquifers and in petroleum reservoirs. The digital deposit will be a synthetic but realistic data set for use in computational experiments in hydrogeology. As such, it will have a sedimentary architecture that is consistent with known depositional processes, with the shapes and scales of depositional bedforms, and with field measurements of stratification geometries and grain-size variations. Developing a digital deposit over this range of scales will require quantifying the three-dimensional architecture from a large amount of data collected within a modern river system, developing simulation algorithms tailored to those findings, and developing efficient means of computational storage. The model will be created with geometric simulation on a centimeter-spaced regular grid that facilitates its import into other types of numerical models (e.g., models for ground-water flow and transport). The digital deposit, together with its unique storage structure and generating algorithms, will be made freely available to the research community.

0510819Ritzi 地下水流和输送的复杂性和不确定性与天然多孔介质水力特性的异质性有关。在沉积物沉积物中，这种非均质性与沉积结构有关，其中重要的方面是沉积单元的比例、几何形状和并置关系。这些单元是在不同的沉积和侵蚀过程中在不同的空间尺度上创建的，并在分层框架内组织起来。 必须在水文地质模型中实现含水层结构的真实表示，因为地质结构从最大无序状态减少了水力特性的熵。同时，与来自最大熵空间场的那些结构相比，这些结构可以在输运统计中产生更大的熵（例如，在较低渗透性背景中包含互连砾石单元的模型在质量停留时间统计中比包含随机、不连接的模型具有更大的方差）砾石块）。沉积矿床的数字表示将通过从厘米尺度到公里尺度的真实建筑来创建。具有如此规模范围的模型是前所未有的。数字矿床将代表含水层和石油储层中常见的河流辫状带沉积物的分层沉积结构。数字存款将是一个合成但真实的数据集，用于水文地质学的计算实验。因此，它将具有与已知沉积过程、沉积床形态的形状和规模以及分层几何形状和粒度变化的现场测量一致的沉积结构。开发这种规模的数字矿藏需要从现代河流系统中收集的大量数据中量化三维架构，开发针对这些发现的模拟算法，并开发有效的计算存储手段。该模型将通过在厘米间隔的规则网格上进行几何模拟来创建，以便于将其导入其他类型的数值模型（例如地下水流和运输模型）。 数字存款及其独特的存储结构和生成算法将免费提供给研究界。