Ecohydrological particle model based on representative domains

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. ... mehrThe 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.