Non-uniform infiltration and subsurface flow in structured soils is observed
in most natural settings. It arises from imperfect lateral mixing of fast
advective flow in structures and diffusive flow in the soil matrix and
remains one of the most challenging topics with respect to match observation
and modelling of water and solutes at the plot scale.This study extends the fundamental introduction of a space domain random walk
of water particles as an alternative approach to the Richards equation for
diffusive flow (Zehe and Jackisch 2016) to a stochastic–physical model framework
simulating soil water flow in a representative, structured soil domain. The
central objective of the proposed model is the simulation of non-uniform flow
fingerprints in different ecohydrological settings and antecedent states by
making maximum use of field observables for parameterisation. Avoiding
non-observable parameters for macropore–matrix exchange, an energy-balance
approach to govern film flow in representative flow paths is employed. We
present the echoRD model (ecohydrological particle model based on
representative domains) and a series of application test cases.The model proves to be a powerful alternative to existing dual-domain models,
driven by experimental data and with self-controlled, dynamic
macropore–matrix exchange from the topologically semi-explicitly defined structures.</p
