Stochastic modeling of transport and degradation of reactive solutes in heterogeneous aquifers

摘要

Hydraulic conductivity fields (K) and degradation rate constants (a) arecommonly used in predicting the fate and transport of reactive contaminants. Thenatural heterogeneity in aquifer porous materials and its effect on hydrologicalparameters such as K and a has to be accounted for by using an appropriate stochasticapproach.The spatial distribution of K and its correlation with a were examined. Randomfields of K having prescribed mean, variance, and correlation lengths were generatedusing the HYDRO_GEN method. Transport simulations were conducted for anensemble of two-dimensionally heterogeneous aquifers. Both positive and negativecorrelations of K and a were considered.The solute??s remaining mass in both the positive and negative correlationscenarios was found to be, on average, within a small range. Concentration profiles fora positive K-a correlation displayed a more uniform behavior of the contaminatedplume, compared to a more variable spreading in the negatively correlated cases.