Furrow Irrigation Simulation Time Reduction

Abstract

Temporal and spatial changes in the flow profile decrease with time under furrow irrigation, and these slow changes suggest modifications in the simulation methods. Geometrically increasing time steps and node deletion at the upstream boundary are introduced and evaluated for accuracy and CPU time reduction. Increasing the time steps reduced CPU time without sacrificing accuracy significantly in predicting advance. The geometric progression factor is estimated automatically from the first two advance increments, thus incorporating site‐specific flow and infiltration characteristics. The moving left boundary method is slightly more accurate, but is less cost‐efficient than the varying time‐step modification for the example conditions. However, special infiltration conditions may favor the latter method.