Application of RZWQM in Predicting Subsurface Drainage under Nova Scotia Conditions

Abstract

The Root Zone Water Quality Model (RZWQM) was calibrated and validated to estimate subsurface drain discharge rates for selected Nova Scotia conditions. The model was calibrated for a shallow, imperfectly drained soil at 80 cm drain depth with 100 mm drain diameter using data collected in 1997. The calibrated model was then validated for three shallow, imperfectly-to-poorly drained soil types at 50 and 80 cm drain depths using field data from both 1996 and 1997. The average mean of differences, the average absolute deviations, the standard error and the standard deviation ranged from 0.01–0.47, 0.12–1.19, 0.30–1.70 and 0.29–1.67 mm d−1, respectively. The R2 values for calibrated and validated (for all soil types) plots were 0.60 and 0.57, respectively. It can be concluded that RZWQM may be used in predicting drain discharge rates for designing and operating subsurface drainage systems in Nova Scotia.