Two-Dimensional Simulation Model for Contour Basin Layouts in South East Australia

Contour basin irrigation layouts are used to irrigate rice and other cereal crops on heavy cracking soils in South East Australia. In the present study, a physically based two-dimensional simulation model that incorporates all the features of contour basin irrigation systems is developed. The model's governing equations are based on a zero-inertia approximation to the two-dimensional long wave equations of motion. The equations of motion are transformed into a single non-linear advection-diffusion equation in which the friction force is described by Manning's formula. The empirical Kostiakov equation and the quasi-analytical Parlange equation are used to model the infiltration process. The governing equations are solved by using a split-operator approach. The numerical procedure is capable of accommodating multiple interconnected basins as used in typical commercial layouts. The model was verified against field data collected on commercial lasered contour layouts.