Pumping-induced Well Hydraulics and Groundwater Budget in a Leaky Aquifer System with Vertical Heterogeneity in Aquitard Hydraulic Properties  

作　　者：ZHUANG Chao LÜChenyang YAN Long LI Yabing ZHOU Zhifang WANG Jinguo DOU Zhi Walter A.ILLMAN 

机构地区：[1]School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,China [2]School of Geography,Earth and Environmental Sciences,University of Birmingham,Birmingham B152TT,U.K. [3]Department of Modern Mechanics,University of Science and Technology of China,Hefei 230027,China [4]Department of Earth and Environmental Sciences,University of Waterloo,Ontario N2L 3G1,Canada

出　　处：《Acta Geologica Sinica(English Edition)》2024年第2期477-490,共14页地质学报（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(Grant No.2019YFC1804301);the National Science Fourdation of China(Grant No.42272279,41902244);partial support from a Discovery Grant awarded by the Natural Sciences and Engineering Research Council of Canada(NSERC)。

摘　　要：In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity(K)and specific storage(S_(s)).The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or S_(s).Two scenarios of analytical investigations are explored:one is the presence of aquitard interlayers with distinct K or S_(s) values,a common field-scale occurrence;another is an exponentially depth-decaying aquitard S_(s),a regional-scale phenomenon supported by statistical analysis.Analytical investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion;a high-S_(s) interlayer can noticeably reduce aquifer drawdown and increase aquitard depletion.Locations of low-K or high-S_(s) interlayers also significantly impact well hydraulics and groundwater budget.In the context of an exponentially depth-decaying aquitard S_(s),a larger decay exponent can enhance aquifer drawdown.When using current models with a vertically homogeneous aquitard,half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard S_(s) should be used to calculate aquitard depletion and unconfined aquifer leakage.

关 键 词：HYDROGEOLOGY AQUITARD vertical heterogeneity semi-analytical solution well hydraulics groundwater budget 

分 类 号：P641[天文地球—地质矿产勘探]