Simulation modeling of border irrigation performance under different soil texture classes and land uses

Abstract

This paper aims for evaluating the border irrigation performance sensitivity including application efficiency, advance time, runoff and deep infiltration ratios to the variation of soil texture, land use, discharge, border length and soil moisture. The measurement of infiltration was done by the double-ring method in five soil texture classes and three land uses. HYDRUS-1D model was calibrated for simulating infiltration in various initial soil moisture. Next, calculated infiltration parameters by HYDRUS-1D were presented to SIRMOD for simulating border irrigation in the various lengths of the border and discharges. The result showed by decreasing the soil moisture, the variation of the performance parameters has possessed a trend of increasing, but for the runoff ratio. Therefore, by incrementing the irrigation period, application efficiency will be incremented. Under different soil textures and land uses, the deep infiltration and runoff ratios were the most and least sensitive parameters concerning soil moisture. Most variations of performance parameters were in sandy loam texture and wheat land use, however, the least variations of the parameters were in silty loam texture and fallow land use. To decrease application efficiency sensitivity to soil moisture, discharge and border length must be considered less and more for soils with great permeability than for soils with little permeability, respectively.