Assessment of HYDRUS-2D performance in simulating wetting patterns in stratified soil profiles under subsurface drip irrigation
Keywords:
Hydrus-2D, Subsurface Drip Irrigation, Wetting Pattern, Stratified soil, Homogeneous Soils.Abstract
Water scarcity in arid and semi-arid regions needs efficient irrigation solutions such as subsurface drip irrigation (SDI). This study investigates soil wetting patterns under SDI in both homogeneous and layered soil profiles using laboratory experiments and numerical simulations via HYDRUS-2D. The experiments examined wetting front advancement in sandy loam and silty clay loam soils using an iron container in the shape of a rectangular open at the top, with the emitter positioned at various depths relative to soil interfaces. Wetting patterns dimensions from laboratory measurements were compared with simulated ones and statistically evaluated using RMSE, MAE, ME and R². The findings revealed good agreement between observed and simulated wetting fronts in homogeneous soils. In layered profiles, good compatibility was noted for horizontal and downward water movement, while upward movement across coarse-to-fine interfaces showed discrepancies, indicating challenges in modeling capillary barriers. Overall, HYDRUS-2D proved to be an effective tool for predicting moisture distribution in complex soil conditions, supporting better SDI design and water management practices.
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