Resumen de The scale dependence of dispersivity in multi-facies heterogeneous formations
Shuning Dong, Zhenxue Dai, Jingsheng Li, Wanfang Zhou
Dispersivity, a parameter describing dispersive mixing of solutes in aquifers, is scale dependent. Macrodispersion coefficient equations are developed for solute transport in three-dimensional domains based on a general global covariance function of log conductivity in multi-facies heterogeneous formations. The longitudinal dispersivity was then derived to show the scale dependence of this parameter. The time evolution trends and the relative contributions of the auto- and cross-facies transition terms to the macrodispersion were discussed with an example. Sensitivity analysis indicates that the values of the longitudinal dispersion coefficient are positively correlated to facies mean length and the difference of the mean log conductivity between different facies. The longitudinal dispersivity coefficient also shows clearly a linear dependence on the global variance of the log conductivity in the multi-facies sediments.
