Evaluation of RZWQM Predictions of Pesticide Fate and Transport Against Measured Data.

Accurate description of pesticide degradation and sorption in soil is important for predicting pesticide fate and transport. The distinguishing features of RZWQM relevant to pesticide degradation and sorption were evaluated against data generated from laboratory and field studies. The pH-dependent sorption of ionized pesticides and the effect of soil pH on leaching and transport of the pesticides in soil were also demonstrated using RZWQM. Evaluations of RZWQM using data collected under a range of environmental conditions indicate that the model satisfactorily simulated pesticide fate and transport in soil. This presentation further shows that the integration of several unique features makes RZWQM a superior tool for predictions of pesticide leaching in soil, which in turn provides basis for use of the model in ground water risk assessment.