Interest in computer models of environmental systems has increased in recent
years. A well formulated model can help engineers and scientists increase their
understanding of a system's dynamics by predicting details and feafures of the system not
easily revealed by experiment. Also, once a model has been validated, it can be used to
predict a system's response to internal or external changes in parameters and/or stimuli.
For example, groundwater flow models constitute a very valuable tool in assessing the
contamination potential of hazardous waste sites, dumps or spills. Similarly, a well
formulated model of landfill stabilization, which is as mechanistic as possible, yet simple
in its assumptions and utilization, can be useful in understanding and managing the
process of stabilization at sanitary landfills.