Stochastic Quantification of Spatial Variability of Flow Fields in Heterogeneous, Non-uniform, Confined Aquifers

IF 2.7 3区 工程技术 Q3 ENGINEERING, CHEMICAL
Chuen-Fa Ni, Ching-Min Chang, Chi-Ping Lin, I-Hsian Lee
{"title":"Stochastic Quantification of Spatial Variability of Flow Fields in Heterogeneous, Non-uniform, Confined Aquifers","authors":"Chuen-Fa Ni,&nbsp;Ching-Min Chang,&nbsp;Chi-Ping Lin,&nbsp;I-Hsian Lee","doi":"10.1007/s11242-024-02084-x","DOIUrl":null,"url":null,"abstract":"<div><p>Stochastic quantification of flow field variability in complex geologic formations under uncertainty is expected to provide valuable information for rational management of regional groundwater resources and analysis of solute transport processes for stochastic environmental risk assessment. Studies of fluid flow behavior in confined aquifers of variable thickness presented in the literature assume that the thickness of the aquifer varies linearly or nonlinearly. However, natural variations, such as the thickness of the aquifer caused by complex natural events, cannot be accurately predicted. Therefore, quantifying the variability of the flow field in heterogeneous, non-uniform, confined aquifers may be done from a stochastic perspective. In this study, the spatial variations in hydraulic conductivity are considered as a stationary random process, while the spatial variations in aquifer thickness are treated as a nonstationary random process with homogeneous (stationary) increments. General expressions for the spatial covariance functions and the evolutionary power spectra of the depth-averaged hydraulic head and integrated specific discharge in the direction of <i>x</i><sub>1</sub> are derived using the Fourier–Stieltjes spectral representation approach and representation theorem. Closed-form solutions for the evolutionary power spectra of depth-averaged hydraulic head and integrated specific discharge are used to analyze the effect of variation in the thickness of the confined aquifer on the variability of depth-averaged head and integrated discharge. An application of the theory developed here to the case of random aquifer thickness fields exhibiting a power-law semivariogram is given. The results of this study improve the understanding and quantification of flow field variability in natural confined aquifers.</p></div>","PeriodicalId":804,"journal":{"name":"Transport in Porous Media","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Transport in Porous Media","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11242-024-02084-x","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0

Abstract

Stochastic quantification of flow field variability in complex geologic formations under uncertainty is expected to provide valuable information for rational management of regional groundwater resources and analysis of solute transport processes for stochastic environmental risk assessment. Studies of fluid flow behavior in confined aquifers of variable thickness presented in the literature assume that the thickness of the aquifer varies linearly or nonlinearly. However, natural variations, such as the thickness of the aquifer caused by complex natural events, cannot be accurately predicted. Therefore, quantifying the variability of the flow field in heterogeneous, non-uniform, confined aquifers may be done from a stochastic perspective. In this study, the spatial variations in hydraulic conductivity are considered as a stationary random process, while the spatial variations in aquifer thickness are treated as a nonstationary random process with homogeneous (stationary) increments. General expressions for the spatial covariance functions and the evolutionary power spectra of the depth-averaged hydraulic head and integrated specific discharge in the direction of x1 are derived using the Fourier–Stieltjes spectral representation approach and representation theorem. Closed-form solutions for the evolutionary power spectra of depth-averaged hydraulic head and integrated specific discharge are used to analyze the effect of variation in the thickness of the confined aquifer on the variability of depth-averaged head and integrated discharge. An application of the theory developed here to the case of random aquifer thickness fields exhibiting a power-law semivariogram is given. The results of this study improve the understanding and quantification of flow field variability in natural confined aquifers.

Abstract Image

异质、不均匀、封闭含水层流场空间变异性的随机量化
在不确定的情况下,对复杂地质构造中的流场变化进行随机量化,有望为合理管理区域地下水资源和分析溶质迁移过程提供有价值的信息,从而进行随机环境风险评估。文献中对厚度可变的承压含水层中流体流动行为的研究假设含水层的厚度呈线性或非线性变化。然而,自然变化,如复杂的自然事件造成的含水层厚度变化,是无法准确预测的。因此,可以从随机的角度对异质、非均匀、承压含水层的流场变化进行量化。在本研究中,水力传导率的空间变化被视为静止随机过程,而含水层厚度的空间变化则被视为具有同质(静止)增量的非静止随机过程。利用傅里叶-Stieltjes 频谱表示法和表示定理,推导出 x1 方向的空间协方差函数以及深度平均水头和综合比排量的演化功率谱的一般表达式。利用深度平均水头和综合比排量演化功率谱的闭式解,分析了承压含水层厚度变化对深度平均水头和综合排量变化的影响。研究还给出了在含水层厚度随机场呈现幂律半变量图情况下的应用理论。这项研究的结果提高了对天然封闭含水层流场变化的理解和量化。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Transport in Porous Media
Transport in Porous Media 工程技术-工程:化工
CiteScore
5.30
自引率
7.40%
发文量
155
审稿时长
4.2 months
期刊介绍: -Publishes original research on physical, chemical, and biological aspects of transport in porous media- Papers on porous media research may originate in various areas of physics, chemistry, biology, natural or materials science, and engineering (chemical, civil, agricultural, petroleum, environmental, electrical, and mechanical engineering)- Emphasizes theory, (numerical) modelling, laboratory work, and non-routine applications- Publishes work of a fundamental nature, of interest to a wide readership, that provides novel insight into porous media processes- Expanded in 2007 from 12 to 15 issues per year. Transport in Porous Media publishes original research on physical and chemical aspects of transport phenomena in rigid and deformable porous media. These phenomena, occurring in single and multiphase flow in porous domains, can be governed by extensive quantities such as mass of a fluid phase, mass of component of a phase, momentum, or energy. Moreover, porous medium deformations can be induced by the transport phenomena, by chemical and electro-chemical activities such as swelling, or by external loading through forces and displacements. These porous media phenomena may be studied by researchers from various areas of physics, chemistry, biology, natural or materials science, and engineering (chemical, civil, agricultural, petroleum, environmental, electrical, and mechanical engineering).
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信