HR: 1340h
AN: H23E-1472    [Abstracts]
TI: Transport of reactive contaminants in physically and chemically heterogeneous aquifers: Effect of the correlation between hydraulic conductivity and degradation rate
AU: * Cunningham, J A
EM: cunning@eng.usf.edu
AF: University of South Florida, Department of Civil & Environmental Engineering, Tampa, FL 33620 United States
AU: Fadel, Z J
EM: zfadel@neo.tamu.edu
AF: Texas A&M University, Department of Civil Engineering, College Station, TX 77843 United States
AB: We have examined the importance of the correlation between hydraulic conductivity (K) and degradation rate (k) during the transport of reactive contaminants in heterogeneous aquifers. We performed a Monte Carlo analysis by simulating reactive transport in an ensemble of two-dimensional heterogeneous aquifers. Two sets of transport simulations were conducted: one in which a perfect positive correlation was assumed between ln(K) and ln(k), and one in which a perfect negative correlation was assumed. We found that the sign of the correlation can have important consequences for the contaminant transport, both in a qualitative and quantitative sense. Qualitatively, a negative correlation leads to ``fingering'' of the contaminant plume, whereas a positive correlation leads to behavior that is similar to that in a homogeneous aquifer. Quantitatively, we found that the mean behavior (as quantified by the contaminant mass remaining in the aquifer) is statistically different between the positive and negative cases, which may contradict the results found by previous researchers. Also, the negative correlation leads to significantly more variability between realizations of the ensemble, whereas a positive correlation induces relatively little variability between realizations. The results of this study have important implications for the management of contaminated aquifers. First, it may be important to know if the correlation between K and k is positive or negative, because the mean behavior is different in these two cases. Second, if actual aquifers are believed to exhibit a positive correlation between K and k, then it may be acceptable to ignore the heterogeneity, because the results from positive-correlation simulations are similar to the results in a homogeneous aquifer. However, if actual aquifers are believed to exhibit a negative correlation between K and k, then the heterogeneity is important, because the resultant behavior can differ significantly from the homogeneous case.
DE: 1800 HYDROLOGY
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: Fall Meeting 2005