Groundwater models are used to evaluate whether sources of pollution are likely to contaminate water wells used to supply water to communities and industry. Because of sparse data, inaccessibility of the subsurface, problems that obscure the relation between field measurements and simulated quantities, and the urgent needs of society to make important water-resource decisions, groundwater modeling presents one of the most challenging modeling situations in the natural sciences and engineering.
The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy and the U.S. Department of Defense, has been working to develop these two approaches of making groundwater models more reliable. The USGS recently improved its already very widely used groundwater model, MODFLOW, to include the most recent advances in comparing computed and measured values and displaying these comparisons in standardized, easy to understand ways. MODFLOW now also allows geologic information to be more easily included in a groundwater model.
MODFLOW is available for free to all users at http://water.usgs.gov -- click on "software" under Technical Resources, then click "Ground Water" and then "MODFLOW-2000."SOURCE: U.S. Geological Survey