ABSTRACT
ABSTRACT: Heterogeneity of the subsurface has a significant impact on groundwater flow and transport. The analysis of heterogeneous groundwater systems remains difficult because the effects of heterogeneity are poorly understood. The differences in methods used to calculate average flow properties can create discrepancies in flow and transport predictions. Well known simple solutions exist for hydraulic conductivity averaging in layered aquifers, but analogies in fractured rock settings are lacking. The layered aquifer solutions are used as an analogy to examine flow through heterogeneous fracture planes. These solutions are also evaluated to determine asymptotic solutions for situations with extreme heterogeneity. Analyzing a simple two-layer system, analytical solutions of the influence of heterogeneity on layered aquifers and fractures can be determined. The analytical solution for average hydraulic conductivity perpendicular to fracture plane heterogeneities is slightly different than the layered aquifer solution. Results show that perpendicular flow through heterogeneous fractures is more sensitive to heterogeneity than in layered aquifers. The results also demonstrate that with low levels of heterogeneity, flow is controlled by extremes of hydraulic conductivity.
