engleski

Quantification of Local Scale Preferential Flow and Nonlinear Solute Transport Processes in Highly Structured Soils

Water and solute fluxes depend on soil hydraulic properties which are subjected to horizon-specific pedological changes across space and time. Terrain inclination and soil structural development shape the hydraulic properties of soil horizons and thus, distribution of water and solute fluxes. Soil structural development and hydraulic properties are dynamically changing within the soil landscape, even more rapidly in cultivated arable soils. In order to develop pedotransfer functions for the estimation of hydraulic properties from basic soil properties, needed for deterministic descriptions of soil water fluxes and solute dynamics, soil structural and hydraulic properties are required for all soil horizons, including subsurface structures in a 3D soil landscape continuum. Here we provide some of the examples of nonlinear processes quantification with the support of numerical modeling tools. Simulations reveal that identifying and parameterizing the most critical structures is the key for correct quantification of vadose zone processes. Subscale structures that may account for local non-equilibrium conditions and preferential flow could be included by appropriate upscaling of the smaller-scale heterogeneities in the macroscopic scale model approaches. These local-scale processes might have large importance for solute movement in agricultural fields where tillage and trafficking influence the topsoil structure. Challenges remains in correct quantification of local-scale processes and their prediction with vadose zone models.

Preferential flow, transport modeling, mass transport, soil heterogeneity

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