Direct Breakthrough Curve Prediction From Statistics of Heterogeneous Conductivity Fields. Issue 1 (23rd January 2018)

• Record Type: Journal Article
• Authors: Hansen, Scott K.; Haslauer, Claus P.; Cirpka, Olaf A.; Vesselinov, Velimir V.
• Is Part Of: Water resources research. Volume 54:Issue 1(2018)
• Page Start: 271
• Page End: 285
• Publication Date: 2018-01-23
• Subjects: solute transport -- heterogeneity -- upscaling -- predictive modeling -- stochastic hydrogeology; Hydrology -- Periodicals; 333.91
• DOI: 10.1002/2017WR020450
• Languages: English
• ISSNs: 0043-1397

Abstract

Abstract: This paper presents a methodology to predict the shape of solute breakthrough curves in heterogeneous aquifers at early times and/or under high degrees of heterogeneity, both cases in which the classical macrodispersion theory may not be applicable. The methodology relies on the observation that breakthrough curves in heterogeneous media are generally well described by lognormal distributions, and mean breakthrough times can be predicted analytically. The log‐variance of solute arrival is thus sufficient to completely specify the breakthrough curves, and this is calibrated as a function of aquifer heterogeneity and dimensionless distance from a source plane by means of Monte Carlo analysis and statistical regression. Using the ensemble of simulated groundwater flow and solute transport realizations employed to calibrate the predictive regression, reliability estimates for the prediction are also developed. Additional theoretical contributions include heuristics for the time until an effective macrodispersion coefficient becomes applicable, and also an expression for its magnitude that applies in highly heterogeneous systems. It is seen that the results here represent a way to derive continuous time random walk transition distributions from physical considerations rather than from empirical field calibration. Key Points: Lognormal breakthrough curve parameters fitted as functions of variance of log‐hydraulic conductivity and distance to source Estimates are calculated for error of predicted flux‐weighted breakthrough curves and coherence of point breakthrough curves Macrodispersion coefficients are derived for highly heterogeneous media using a breakthrough time‐based approach