Evaluation of the Versatile Soil Moisture Budget model for a humid region in Atlantic Canada

Abstract

In this study, the performance of the Versatile Soil Moisture Budget (VSMB) model was evaluated to simulate soil water content (θ) for a study site near Truro, Nova Scotia, which is a humid region in Atlantic Canada. The risk associated with both surplus and deficit water in this region of Nova Scotia was also quantified. The average root mean squared error (RMSE), mean absolute error (MAE), coefficient of determination (R2), model efficiency (E) and index of agreement (d) of 3.63, 3.08, 0.9, 0.7 and 0.92, respectively, for a validation period (growing season of 2000) suggest that the model performed reasonably well in predicting θ. The results of analysis of simulated θ using the validated model for 1 April to 31 October over a period of 92 years (1910–2001) showed that the likelihood of having deficit [θ ≤ 50% available water (AW)] and severe deficit (θ ≤ 25% AW) events is higher in July and August and it is likely that such events will last longer than a single day. About 94% and 75% of the days in April and October, respectively, have trafficability problems [θ > 92.3% field capacity (FC)], while about 26.5% and 19.4% of the days in April and October, respectively, have crop surplus problems (θ > FC).