Use of Numerical Models to Simulate Groundwater Flow and Transport

In the past, the main driving force for hydrogeologic studies has been the need to assess the water-supply potential of aquifers. During the past 20 years, however, the emphasis has shifted from water-supply problems to water-quality problems. This has driven a need to predict the movement of contaminants through the subsurface environment. One consequence of the change in emphasis has been a shift in perceived priorities for scientific research and data collection. Formerly, the focus was on developing methods to assess and measure the water-yielding properties of high-permeability aquifers. The focus is now largely on transport and dispersion processes, retardation and degradation of chemical contaminants, the effects of heterogeneity on flow paths and trav contain contaminated groundwater.