OSTER COPY 489 `' MODELING TRANSPORT OF BROMIDE IN FURROW-IRRIGATED FIELD

The purpose of this study was to investigate the reliability of combining a surface irrigation model (SRFR) and two functional solute transport models (RAO and TETrans) in predicting the position of bromide (BC) measured in a 0.81-ha field under furrow irrigation. The SRFR model was used to first predict the infiltrated depths and then RAO and TETrans models were used to predict the position of the solute. Solute was transported according to piston flow theory for the first irrigation and both models predicted the position of the solute with good accuracy. The solute was transported slightly faster than estimated by piston flow for the second irrigation, resulting in a reduction of correct predictions by both models. Both models predicted poorly for the third irrigation because deviations from piston flow were large. RAO model was more successful in predicting the peak solute position, while TETrans was more accurate in predicting mean solute depths. The latter was attributed to the differences between the two models and the sensitivity of TETrans to nodal spacing when predicting peak solute position.