Calibration and Reliability in Groundwater
Modelling: Credibility of Modelling
(Proceedings of ModelCARE 2007 Conference, held in
Denmark, September 2007). IAHS Publ. 320, 2008, 210-213.
Upscaling of solute transport based on the concept of the memory function
G. LLERAR-MEZA1, D. FERNNDEZ-GARCIA2 & J. J. GMEZ-HERNNDEZ1
1 Universidad Politcnica de Valencia, Departamento
de Ingeniera Hidrulica y Medio Ambiente, Camino de Vera,
s/n. 46022 Valencia, Spain
2 Universitat Politcnica de Catalunya, Departament
dEnginyeria del Terreny, Gran Capit, s/n. 08034 Barcelona, Spain
Abstract We evaluate the benefits of using an
alternative upscaled solute transport model in making numerical predictions of
contaminant transport in heterogeneous formation. The transport model is based
on the concept of mass transfer memory functions, which are used to represent
the unresolved mass exchange between highly mobile and less mobile zones
occurring within each grid block of the numerical model. Performance assessment
of the first-order single-rate mass transfer transport model is presented here
for a given highly heterogeneous aquifer realization. To achieve this, solute
transport is solved at different support scales. Upscaling of hydraulic
conductivity is based on the Laplacian method with skin, whereas block
transport parameters are estimated through calibration of block-specific tracer
test breakthrough curves using an inverse optimization technique. A high
resolution hydraulic conductivity map provides the reference transport
solution, which is compared with simulations obtained from the upscaled model.
Simulation of solute transport with mass transfer is based on the
implementation of the multirate mass transfer model into random walk particle
tracking methodology presented by Salamon et al. (2006).
Keywords upscaling; mass transfer; advection; solute transport; memory function