A parsimonious water budget model for Canadian agricultural conditions

Abstract

Study region: This study used data collected from three cropland sites (two in Manitoba and one in Prince Edward Island) in Canada. Study focus: In efforts to accurately describe the water dynamics in agricultural soils, most of the agri-hydrological models developed are highly complex, such that they require detailed input data, of which most of them are not always measured or otherwise readily available. However, the comprehensive and complex representations of the processes may not be justified when data is scarce. Thus, this study developed a soil water budget model that could describe the movement of water through Canadian agricultural soils using a few parameters only. The model was developed by selecting algorithms from various existing models, whose data requirements are readily available in literature and public Canadian databases. New hydrological insights: The model developed in this study can simulate evapotranspiration, runoff, deep percolation, and soil moisture content for various seasons (i.e., growing, non-growing/dormant, and pre-planting/post-harvest) with minimum data requirement, which addresses the limited availability of data in the country for crop and hydrological modeling. Moreover, the model is simple and easy to use, and can work without calibration. It was tested using three site-specific datasets, and results show that despite its simplicity, its overall performance was comparable with those of other agricultural models that use cascade flow framework for hydrology.

Keywords

• Agri-hydrological model
• Deep percolation
• Evapotranspiration
• Runoff
• Soil moisture