DOI: 10.5194/hess-23-1323-2019
论文题名: A general analytical model for head response to oscillatory pumping in unconfined aquifers: Effects of delayed gravity drainage and initial condition
作者: Huang C.-S. ; Tsai Y.-H. ; Hund-Der Y. ; Yang T.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2019
卷: 23, 期: 3 起始页码: 1323
结束页码: 1337
语种: 英语
Scopus关键词: Aquifers
; Boundary conditions
; Groundwater flow
; Groundwater resources
; Hydrogeology
; Laplace transforms
; Pumps
; Sensitivity analysis
; Dimensionless parameters
; General analytical model
; Groundwater flow equation
; Hydraulic head fluctuations
; Neumann boundary condition
; Optimization approach
; Simple harmonic motion
; Vertical hydraulic conductivities
; Analytical models
; analytical method
; boundary condition
; drainage
; gravity flow
; groundwater flow
; hydraulic conductivity
; hydraulic head
; hydrological response
; optimization
; parameter estimation
; pumping
; unconfined aquifer
; water table
; Savannah River
; United States
英文摘要: Oscillatory pumping tests (OPTs) provide an alternative to constant-head and constant-rate pumping tests for determining aquifer hydraulic parameters when OPT data are analyzed based on an associated analytical model coupled with an optimization approach. There are a large number of analytical models presented for the analysis of the OPT. The combined effects of delayed gravity drainage (DGD) and the initial condition regarding the hydraulic head are commonly neglected in the existing models. This study aims to develop a new model for describing the hydraulic head fluctuation induced by the OPT in an unconfined aquifer. The model contains a groundwater flow equation with the initial condition of a static water table, Neumann boundary condition specified at the rim of a partially screened well, and a free surface equation describing water table motion with the DGD effect. The solution is derived using the Laplace, finite-integral, and Weber transforms. Sensitivity analysis is carried out for exploring head response to the change in each hydraulic parameter. Results suggest that the DGD reduces to instantaneous gravity drainage in predicting transient head fluctuation when the dimensionless parameter a1 D Syb=Kz exceeds 500 with empirical constant , specific yield Sy, aquifer thickness b, and vertical hydraulic conductivity Kz. The water table can be regarded as a no-flow boundary when a1 < 102 and P < 104 s, with P being the period of the oscillatory pumping rate. A pseudo-steady-state model without the initial condition causes a time-shift from the actual transient model in predicting simple harmonic motion of head fluctuation during a late pumping period. In addition, the present solution agrees well with head fluctuation data observed at the Savannah River site. © 2019. This work is distributed under the Creative Commons Attribution 4.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/163026
Appears in Collections: 气候变化与战略
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作者单位: Huang, C.-S., State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Center for Global Change and Water Cycle, Hohai University, Nanjing, 210098, China; Tsai, Y.-H., Institute of Environmental Engineering, National Chiao Tung University, Hsinchu, 300, Taiwan; Hund-Der, Y., Institute of Environmental Engineering, National Chiao Tung University, Hsinchu, 300, Taiwan; Yang, T., State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Center for Global Change and Water Cycle, Hohai University, Nanjing, 210098, China
Recommended Citation:
Huang C.-S.,Tsai Y.-H.,Hund-Der Y.,et al. A general analytical model for head response to oscillatory pumping in unconfined aquifers: Effects of delayed gravity drainage and initial condition[J]. Hydrology and Earth System Sciences,2019-01-01,23(3)