首页|Regional-Scale Effects of Glacial Till Aquitard Vertical Heterogeneity on Transient Well Flow and Groundwater Budget With Variable Discharge in Leaky Aquifer Systems

Regional-Scale Effects of Glacial Till Aquitard Vertical Heterogeneity on Transient Well Flow and Groundwater Budget With Variable Discharge in Leaky Aquifer Systems

扫码查看
原文链接
  • NETL
  • NSTL
  • Wiley
In Pleistocene glacial regions, glacial till aquitards typically exhibit a significant regional-scale decrease in hydraulic parameters, such as specific storage (Ss) and hydraulic conductivity (K), with depth due to increased sediment compaction, reduced porosity, and lower pore connectivity. Pumping rates also decrease over time due to equipment wear and hydraulic friction. This study developed a novel analytical model for variable groundwater discharge in a leaky aquifer system, incorporating the often-overlooked vertical heterogeneity of aquitards. The model integrates two exponential decay mechanisms: one for the aquitard Ss and K with depth, and one for the pumping rates over time. Special cases addressing only depth-decaying Ss, depth-decaying K, or constant rates were also derived. New analytical solutions investigate how the decay exponents of aquitard Ss and K, variable pumping rates, and aquitard thickness influence drawdown and groundwater budgets. Results reveal that variable pumping rates cause local maxima and minima in aquifer drawdown, especially with higher decay of Ss and K. While aquitard thickness and pumping rates affect depletion and leakage, changes in the physical properties of aquitards, such as the decay of Ss and K, are more critical in determining the actual patterns of depletion and leakage fractions. Larger Ss decay or smaller K decay enhance early peak depletions caused by time-decaying pumping rates. These results highlight the importance of prioritising depth-dependent parameters in groundwater management, particularly in regions with significant vertical heterogeneity, like glacial deposits. The study offers valuable insights for hydrological assessments and optimising groundwater resource management in similar settings.

aquitardexponential decay mechanismsleaky aquifer systemvariable pumping ratevertical heterogeneity

Yabing Li、Zhifang Zhou、Ning Zhang

展开 >

School of Engineering Sciences, University of Science and Technology of China, Hefei, Anhui Province, China||School of Earth Sciences and Engineering, Hohai University, Nanjing, Jiangsu Province, China

School of Earth Sciences and Engineering, Hohai University, Nanjing, Jiangsu Province, China

College of Civil Engineering, Hefei University of Technology, Hefei, Anhui Province, China

2025

10.1002/hyp.70147

Hydrological processes

Hydrological processes

ISSN：1099-1085
年,卷(期)：2025.39(5)
  • 58