Evaluating cell-based components of DANSAT for predicting surface and subsurface transport of pesticides

Accurate simulation of cell-based processes is important for evaluating the impacts of best management practices (BMPs) on surface and ground water. The objective of this study was to evaluate the cell-based component of the Dynamic Agricultural Non-point Source Assessment Tool (DANSAT) for simulating water, sediment, and pesticide movement both in surface and through the soil profile. DANSAT was applied to a maize field in Virginia cultivated by conventional tillage. The model performed well in predicting seasonal and total surface runoff, sediment load, and pesticides loads. Movements of percolated water and pesticides in the soil profile were also well reproduced by the model with 0.57 and 0.82 average index of agreements, respectively. However, the model had difficulty in predicting the temporal changes in sediment load using the dynamic erodibility approach for estimating daily variable rill and interrill erodibility parameters. The overall result showed that the cell-based component of DANSAT could be used for further evaluation of BMP impacts on surface and ground water at the watershed-scale.