title: Development of a dual permeability model within a hydrological catchment modeling framework: 1D application.
abstract: Preferential flow contributes significantly to pesticide fast transfer from surface to groundwater. Modeling this process at several scales is an important challenge for improving the representation of this process which is often neglected. In this study, we developed a dual permeability approach in a hydrological modeling framework, CMF, which is a collaborative environment for developing spatially-integrated models of water fluxes. In the development we propose here, infiltration in macropores which are connected to the surface is activated when the first matrix layer reaches saturation. A transfer function is used to represent water fluxes from macropores to matrix. This approach is tested in 1D by comparison with the dual permeability approach included in Hydrus1D, on 4 typical soil-types (sandy-loam, silty-loam, clay-loam and sandy-clay-loam). The results showed an underestimation of the flux infiltrated in the matrix surface and important infiltration in macropores with the new model, for most of soil-types, comparing to Hydrus1D. Similarities are observed for fluxes transferred from macropores to matrix. Solute transport is then coupled to CMF-DP model considering a convection transport and a linear adsorption to represent pesticides behavior in macroporous soils. The approach we developed is similar to Hydrus though having the advantage to need less input parameters, especially for the exchange between the two porous media. In the future, it could be applied for predicting pesticides transfer in macroporous soils at different scales for operational applications.
authors: Irstea, UR MALY, centre de Lyon-Villeurbanne, 5 rue de la Doua, BP 32108, 69616 Villeurbanne Cedex, France. Electronic address: djabelkhir.k@gmail.com.
authors: K
authors: K
authors: Djabelkhir
authors: Irstea, UR MALY, centre de Lyon-Villeurbanne, 5 rue de la Doua, BP 32108, 69616 Villeurbanne Cedex, France.
authors: C
authors: C
authors: Lauvernet
authors: Institute for Landscape Ecology and Resources Management, Gießen, Germany.
authors: P
authors: P
authors: Kraft
authors: Irstea, UR MALY, centre de Lyon-Villeurbanne, 5 rue de la Doua, BP 32108, 69616 Villeurbanne Cedex, France.
authors: N
authors: N
authors: Carluer
keywords: Catchment Modeling Framework; Dual permeability model; Hydrological modeling; Pesticide transport; Transfer function; Water transport processes