## Abstract

The profiles for the water table height h(x, t) in a shallow sloping aquifer are reexamined with a solution of the nonlinear Boussinesq equation. We demonstrate that the previous anomaly first reported by Brutsaert [1994] that the point at which the water table h first becomes zero at x = L at time t = t_{c} remains fixed at this point for all times t > t_{c} is actually a result of the linearization of the Boussinesq equation and not, as previously suggested [Brutsaert, 1994; Verhoest and Troch, 2000], a result of the Dupuit assumption. Rather, by examination of the nonlinear Boussinesq equation the drying front, i.e., the point x_{f} at which h is zero for times t ≥ t_{c}, actually recedes downslope as physically expected. This points out that the linear Boussinesq equation should be used carefully when a zero depth is obtained as the concept of an "average" depth loses meaning at that time.

Original language | English |
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Journal | Water Resources Research |

Volume | 40 |

Issue number | 4 |

Publication status | Published - Apr 2004 |

Externally published | Yes |

## Keywords

- Drying front
- Nonlinear effects
- Sloping aquifer