Gaussian or non-Gaussian logconductivity distribution at the MADE site: What is its impact on the breakthrough curve?

- We examine the logconductivity distribution at the MADE site.
- The distribution displays some deviation from Gaussianity.
- We measure the impact of the distribution on the BTC.
- Non-Gaussianity at MADE does not significantly affect the BTC.
- Larger impacts can be found for stronger deviations from Gaussianity.

The impact of the logconductivity (Y = ln K) distribution fY on transport at the MADE site is analyzed. Our principal interest is in non-Gaussian fY characterized by heavier tails than the Gaussian. Both the logconductivity moments and fY itself are inferred, taking advantage of the detailed measurements of Bohling et al. (2012). The resulting logconductivity distribution displays heavier tails than the Gaussian, although the departure from Gaussianity is not significant. The effect of the logconductivity distribution on the breakthrough curve (BTC) is studied through an analytical, physically based model. It is found that the non-Gaussianity of the MADE logconductivity distribution does not strongly affect the BTC. Counterintuitively, assuming heavier tailed distributions for Y, with same variance, leads to BTCs which are more symmetrical than those for the Gaussian fY, with less pronounced preferential flow. Results indicate that the impact of strongly non-Gaussian, heavy tailed distributions on solute transport in heterogeneous porous formations can be significant, especially in the presence of high heterogeneity, resulting in reduced preferential flow and retarded peak arrivals.