Environmetrics is a vigorous new discipline that is both complex and diverse. Situated at the intersection of, and overlapping, both the environmental and quantitative sciences, it often seems to defy a precise definition. For our purpose, environmentrics may be most conveniently described by its activity, which is the use of measurements in the analysis, modeling, interpretation, and prediction of environmental phenomena. It is often linked to pollution problems and their impacts upon life support systems. The word itself - environmetrics - was virtually unknown prior to 1970. However, in just three decades, it has become the title of an established scientific journal, a professional society - The International Environmetrics Society (TIES), with an annual scientific conference - and the name of graduate and undergraduate programs at several leading universities. Over these past 30 years, environmetrics has focused on three different, though interrelated objectives. The first objective has been the attempt to formulate a conceptual framework for the use of quantiative methods in the analysis, understanding, and evaluation of environmental problems. Here environmetrics has been synthetic, building its own methods and terminology to deal systematically with the complex issues of quantiative envrionmental science. Second, there has also been a need to create a communication bridge that regularly links quantitative environmental scientists. As in any modern, rapdily-evolving field these multi-disciplinary interactions provide a continuous source of enrichment to the science itself. The third objective has been to promote future growth and development, through various means, including educational and research programs within universities and research institutes. The entries have been written by close to 500 eminent researchers in the field. By design, each technical entry starts with a short introduction to motivate and guide readers towards a better understanding of the material. Actual environmental data sets are frequently employed to illustrate a technique's use and application. Pertinent references are included to aid readers should they desire to pursue the subject beyond the level presented here; occasionally, the authors also provide additional sources for further exploration of the subject matter. In the selection of topics for this Encyclopedia, we have placed substantial emphasis on methods of environmental statistics because of their wide use in environmentric applications and because they have experienced rapid development in recent years. this is due to two major factors: (1) an increase in computing capabilities that has allowed for much greater use of complex, computer-intensive statistical methodologies, and (2) new, emerging challenges in the study of pollutin and other environmental problems, particularly in the areas of spatial and temporal modeling and risk analysis. Where appropriate, we have asked the contributors to identify and incorporate these two important components into their individual entries. We also placed greater emphasis upon the quantification and study of physical processes. In particular, we focused upon topics relating to the modeling and analysis of chemical diffustion and transport in soil, water, and air. As many readers will be aware, these issues have been associated with environmetrics for some time, and their inclusion here is testament to that fact.
