畦灌水流运动对田面糙率的敏感性分析

Sensitivity Analysis of Water flow Movement under Border Irrigation on the Surface Roughness

在模型反演确定田面糙率的基础上,针对田面糙率设计了共8种正负偏离情况,利用winSRFR模型模拟了8种不同田面糙率偏离下畦灌水流运动过程及灌水质量,并分析了糙率偏差对水流推进、消退过程、灌水效率和灌水均匀度的影响。结果表明,田面糙率偏差在±20%以内时,对于畦灌水流运动过程、灌水效率和灌水均匀度影响较小。因此,畦灌数值模拟中,对田面糙率估算精度要求可适当放宽。

On the basis of reversion calculation of field surface roughness through water flow movementmodel, the water flow process and irrigation quality under border irrigation were simulated by using thewinSRFR model under eight different deviations of field surface roughness, and the impacts of roughnessdeviation on water advance process, water recession process, irrigation efficiency and irrigation uniformitywere analyzed. The results showed that the effects of field surface roughness on water flow movement under border irrigation, irrigation efficiency and irrigation uniformity were slight when the deviations of thefield surface roughness changed from --20% to ＋20%. Therefore, the estimation accuracy of the fieldsurface roughness is a less sensitive parameter in numerical simulation of border irrigation.