An alternative Boussinesq equation considering the effect of hysteresis on coastal groundwater waves |
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| Authors: | Jun Kong Zhaoyang Luo Chengji Shen Guofen Hua Hongjun Zhao |
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| Affiliation: | 1. State Key Laboratory of Hydrology‐Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China;2. National Centre for Groundwater Research and Training, School of Civil Engineering, The University of Queensland, Brisbane, Queensland, Australia |
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| Abstract: | This paper presents an alternative Boussinesq equation considering hysteresis effect via a third‐order derivative term. By introducing an improved moisture–pressure retention function, this equation describes, with reasonable precision, groundwater propagation in coastal aquifers subject to Dirichlet boundary condition of different oscillation frequencies. Test results confirmed that it is necessary to consider horizontal and vertical flows in unsaturated zone, because of their variable influences on hysteresis. Hysteresis in unsaturated zone can affect the water table wave number of groundwater wave motion, such as wave damping rate and phase lag. Oscillations with different periods exert different hysteresis effect on wave propagation. Truncation/shrinkage of unsaturated zones also affects the strength of hysteresis. These impacts can be reflected in the alternative Boussinesq equation by adjusting the parameter representing the variation rate of moisture associated with pressure change, as opposed to traditional computationally expensive hysteresis algorithms. The present Boussinesq equation is simple to use and can provide feasible basis for future coupling of groundwater and surface water models. Copyright © 2016 John Wiley & Sons, Ltd. |
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| Keywords: | Boussinesq equation unsaturated zone hysteresis effect groundwater wave water table wave number |
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