In all cases, the average coefficient of determination, r2, for the predicted BTCs was 0.99. For a vertical TDR probe method, there was not always full agreement between the TDR determined parameters and effluent determined parameters. However, predicted BTCs obtained from the TDR method were similar to the observed BTCs with the average r2 being 0.94. The ST method and the two TDR methods are promising methods for estimating MIM parameters. The TDR methods are relatively simple and reliable. Furthermore, TDR is portable and can be multiplexed so that one can install probes at multiple locations in field. However, the TDR methods should be further examined in situ.

Transport and retention of water, nutrients, and inorganic and organic contaminants in the environment is greatly affected by physical and chemical processes in porous media such as soils. To definitively understand these processes, multiple scales--ranging from the landscape to the molecular--be investigated. Topics include fractal and spatial heterogeneity, molecular models, in situ spectroscopic and microscopic techniques, and inclusion of time-dependent phenomena in predicting solute transport/retention in soils.