A new solution for a partially penetrating constant‐rate pumping well with a finite‐thickness skin |
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| Authors: | Pin‐Yuan Chiu Hund‐Der Yeh Shaw‐Yang Yang |
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| Institution: | 1. Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Taiwan;2. Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, TaiwanInstitute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Taiwan;3. Department of Civil Engineering, Vanung University, Chungli 320, Taiwan |
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| Abstract: | A mathematical model describing the constant pumping is developed for a partially penetrating well in a heterogeneous aquifer system. The Laplace‐domain solution for the model is derived by applying the Laplace transforms with respect to time and the finite Fourier cosine transforms with respect to vertical co‐ordinates. This solution is used to produce the curves of dimensionless drawdown versus dimensionless time to investigate the influences of the patch zone and well partial penetration on the drawdown distributions. The results show that the dimensionless drawdown depends on the hydraulic properties of the patch and formation zones. The effect of a partially penetrating well on the drawdown with a negative patch zone is larger than that with a positive patch zone. For a single‐zone aquifer case, neglecting the effect of a well radius will give significant error in estimating dimensionless drawdown, especially when dimensionless distance is small. The dimensionless drawdown curves for cases with and without considering the well radius approach the Hantush equation (Advances in Hydroscience. Academic Press: New York, 1964) at large time and/or large distance away from a test well. Copyright © 2007 John Wiley & Sons, Ltd. |
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| Keywords: | groundwater analytical solution constant pumping test heterogeneous aquifer finite Fourier cosine transforms Laplace transforms partially penetrating well |
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