Simulation of Unsteady Flow and Soil Erosion in Irrigation Furrows

Abstract

This study developed a one-dimensional numerical model for the simulation of unsteady flow and the resultant soil erosion in irrigation furrows. The model solves a modified version of the Saint-Venant equations that consider the loss of mass and momentum attributable to infiltration and sediment transport. The transport rate of fine sediment was predicted with a modified Laursen formula that treats the tractive shear stress as a function of both Reynolds number and the particle size. The modified Laursen formula was verified by using the erosion data measured in the field and in a laboratory flume. The model accurately predicted flow advance times and outflow hydrographs in comparison with data measured in irrigation furrows at Kimberly, Idaho. Sediment discharge predictions were less accurate.