Experimental and Numerical Simulation Study of Flow and Solute Transport in Pore-Fractured Media Based on High-Density Resistivity Method

Abstract

Pore-fractured media is a ubiquitous phenomenon throughout the world and is a high degree of heterogeneity. The mechanism of water flow and solute transport in the media is still not fully clear. In this study, experiments were conducted in pore-fracture media with various hydraulic gradients to establish the relationship between the hydraulic gradient and specific discharge by using a side guide and to test the resistivity of tracer (sodium chloride) by using a high-density resistivity monitoring system. Quantifying models were, respectively, set up, and results were compared with the traditional methods. Main results are obtained that (1) the phenomenon from Darcian flow to non-Darcian flow was found in pore-fractured media. Both the Forchheimer and Izbash equations can well describe the flow process in the back part of the curve; (2) the phenomenon from non-Fickian to Fickian then to non-Fickian was found in fractured media; (3) good performance of CTRW-TPL has been obtained for both the larger R2 and smaller RMSE values, their counterparts resulting from the ADE model.