Descriptions of anisotropy and heterogeneity and their effect on ground-water flow and areas of contribution to public supply wells in a karst carbonate aquifer system

MODFLOW and MODPATH numerical models were used to generate areas of contribution to public supply wells for simulated hypothetical anisotropy and heterogeneous carbonate aquifer systems. The simulations incorporated, to varying degrees, the anisotropy and heterogeneity observed in a karst carbonate aquifer system. These include: isotropic and homogeneous single-layer system, doubly-porous single-layer system, and interconnected vertically and horizontally heterogeneous system. The study indicated that the distribution and nature of aquifer anisotropy and heterogeneity will affect the simulated size, shape, and orientation of areas of contribution in karst carbonate aquifer systems.