Simulating elevation and infiltration in level-basin irrigation

Several authors have reported that the spatial variability of infiltration and soil surface elevation can have a pronounced effect on surface irrigati on performance. This study was conducted to assess the improvement of the p redictive capability of a level-basin irrigation model when both sources of spatial variability are considered. A 2D simulation model was used to simu late irrigation events with or without spatial variability of infiltration and/or elevation. Four irrigations that were applied to a corn crop planted on an experimental, laser-leveled basin were simulated. Introducing soil s urface elevation variability improved the quality of the simulation of adva nce, recession, and crop yield, whereas introduction of infiltration variab ility did not. If infiltration is randomly distributed in the basin, it doe s not seem justified to introduce its variability in the model. As for soil surface elevation variability, its introduction would be justified even if laser leveling was used. Finally, the introduction of both sources of vari ability led to an accurate estimation of distribution uniformity.