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A metahillslope model based on an analytical solution to a linearized Boussinesq equation for temporally variable recharge rates
Author(s) -
Pauwels Valentijn R. N.,
Verhoest Niko E. C.,
De Troch François P.
Publication year - 2002
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2001wr000714
Subject(s) - groundwater recharge , aquifer , base flow , infiltration (hvac) , hydrology (agriculture) , hydrograph , water table , groundwater flow , richards equation , flow (mathematics) , environmental science , surface runoff , geology , groundwater , mathematics , drainage basin , soil science , geotechnical engineering , geometry , meteorology , physics , ecology , cartography , soil water , geography , biology
In hydrology the slow, subsurface component of the discharge is usually referred to as base flow. One method to model base flow is the conceptual approach, in which the complex physical reality is simplified using hypotheses and assumptions, and the various physical processes are described mathematically. The purpose of this paper is to develop and validate a conceptual method, based on hydraulic theory, to calculate the base flow of a catchment, under observed precipitation rates. The governing groundwater equation, the Boussinesq equation, valid for a unit width sloping aquifer, is linearized and solved for a temporally variable recharge rate. The solution allows the calculation of the transient water table profile in and the outflow from an aquifer under temporally variable recharge rates. When a catchment is considered a metahillslope, the solution can be used, when coupled to a routing model, to calculate the catchment base flow. The model is applied to the Zwalm catchment and four subcatchments in Belgium. The results suggest that it is possible to model base flow at the catchment scale, using a Boussinesq‐based metahillslope model. The results further indicate that it is sufficient to use a relatively simple formulation of the infiltration, overland flow, and base flow processes to obtain reasonable estimates of the total catchment discharge.