Exploring the Statistical Method of Moments for Solute Transport in Fractured Porous Rock Aquifers: Bridging the Gap between Local and Regional Scales
This study uses the Method of Moments (MoM) to define formation-specific macrodispersivities for the simulation of transport and the delineation of capture zones in fractured porous media. This combines the advantages of the efficient Equivalent Porous Medium (EPM) method, which has limited validity, and the Discrete Fracture Matrix (DFM) method, which is unconditionally valid but impractical for regional-scale applications. The underlying concept was shown to be valid for highly heterogeneous systems by embedding it into a stochastic process and using data from the Gasport formation (Guelph, ON). Challenges encountered include the limitations of available computing power, which forced reducing the 3D system to 2D, in turn affecting the modelled transport behaviour. Uncertainties in the macrodispersivities due to MoM implementation were dominated by uncertainties due to hydrogeologic heterogeneities. Overall, a MoM-enhanced regional-scale EPM model can be an efficient tool for simulating transport and delineating capture zones in fractured porous media.