ABSTRACT
Much of the scientific fascination with the environment lies in its incredible complexity. It consists of a large number of phases such as air, soil, and water, which vary in properties and composition from place to place (spatially) and with time (temporally). It is very difficult to assemble a complete, detailed description of the condition (temperature, pressure, and composition) of even a small environmental system or microcosm consisting, for example, of a pond with sediment below and air above. It is thus necessary to make numerous simplifying assumptions or statements about the condition of the environment. For example, we may assume that a phase is homogeneous, or it may be in equilibrium with another phase, or it may be unchanging with time. The art of successful environmental modeling lies in the selection of the best, or “least-worst,” set of assumptions that yields a model that is not so complex as to be excessively difficult to understand yet is sufficiently detailed to be useful and faithful to reality. The excessively simple model may be misleading. The excessively detailed model is unlikely to be useful, trusted, or even understandable. The aim is to suppress the less necessary detail in favor of the important processes that control chemical fate.
