One-Dimensional Coupled Model of Surface Water Flow and Solute Transport for Basin Fertigation

Abstract

A highly efficient and accurate numerical model of surface water flow and solute transport is useful in the design and evaluation of a basin fertigation system. In this study, a coupled model of surface water flow and solute transport for basin fertigation was first formulated. On the basis of the implicit–explicit time scheme of governing equation of the coupled model, the advection upstream splitting method (AUSM) and central finite-volume methods with scalar dissipation characteristic were employed to discretize the spatial derivatives of physical flux, spatial derivatives of advection matrix, diffusion vector, and water-level slope vector. The forming discretized algebraic equation group of the governing equation was solved in split technique, and a one-dimensional surface-flow and solute-transport coupled numerical model for basin fertigation was proposed. The ability of the proposed model was demonstrated using two numerical tests compared with the model on the basis of the Roe finite-volume method. Three field experiments were conducted to validate the proposed model. The results showed that the model exhibits excellent performance for determining water flow and solute transport under full-time, first-half, and second-half fertilizer-application experiments. The proposed model can serve as a research and practical tool for the design and management of basin fertigation.