Effect of porous medium heterogeneity on water flow: a stochastic hydrofacies approach

A stochastic hydrofacies (descriptive-numerical) approach is evaluated by investigating the influence of hydrogeological heterogeneity on the unsaturated zone water dynamics. The approach develops a reliable means for simulating the volumetric water content (θ) and water front arrival time (ta) in both space and time domains. The methodology designed for this purpose integrates Sequential Indicator Simulation (SIS) and Monte Carlo (MC) procedure to generate descriptive realizations of flow units and convert them into numerical hydrofacies. Flow simulation output indicates that the statistical distribution captures θ experimental measurements. In addition, mode values of the stochastic approach fairly represent the observed θ values. The absolute error between mode and field-measured θ values reaches up to 7%. This small error supports the practicality of the approach as opposed to different deterministic methods. The simulation result also reveals that ta probability distribution function depicts, properly, the effect of medium heterogeneity on flow dynamics and suggests the utilization of this approach in decision-making procedures.