自动调控畦灌系统中调控要素对水流运动过程的影响

Effect of Control Factors on Flow Movement in Border Irrigation System Automatically

自动调控畦灌是提高灌水质量、减少劳动力需求的重要措施。为探究自动调控畦灌系统如何合理选取调控要素,通过畦灌观测试验获取畦田自然参数,结合WinSRFR模型模拟畦灌过程,分析自动调控畦灌系统中停水距离、停水时间和入畦流量对水流运动过程和土壤水分入渗分布的影响规律。结果表明,停水距离和停水时间在田面水流推进过程、消退过程、土壤水分入渗分布以及灌水质量等方面的调节效果相似。对于100 m畦长的典型试验畦田,七成改水、七五改水、八成改水、八五改水、九成改水的调控效果分别对应灌水量70、80、90、100、110 mm。停水时机对畦田后段的水流推进、消退过程影响较大,而对畦田前段的水流推进、消退过程影响较小,不同改水成数或灌水量并不能显著改变畦田前段的土壤水分入渗分布。调控流量较停水距离和停水时间可以更有效地调控畦田前段的灌水效率和灌水均匀度。因此在优先考虑经济性的自动调控畦灌系统中推荐调控灌水量,而在追求精准调控的自动调控畦灌系统中推荐调控流量。

Automatic controlling of border irrigation is an crucial measure to improve irrigation quality and reduce labor demand.To explore the optimal selection of control factors in the automatic controlling border irrigation system,this study obtained the natural parameters of the border field through the observation experiment of border irrigation.These parameters were then combined with the WinSRFR model to simulate the border irrigation process and analyze the effects of the automatic controlling border irrigation system on the flow movement process and soil water infiltration distribution.The results showed that both the water cut-off distance and cut-off time had similar regulating effects on the process of surface flow advancing,receding,soil water infiltration distribution and irrigation quality.For a typical test field with 100m border length,varying cut-off ratios of 70%,75%,80%,85%,and 90%corresponded to the irrigation amount of 70mm,80mm,90mm,100mm and 110mm respectively.Water cut-off time had a greater effect on flow advance and regression in the back part of the border,but had a lesser effect on flow advance and regression in the front part of the border.Soil water infiltration distribution in the front part of the border could not be significantly changed by different water conversion ratios or irrigation amounts.The irrigation efficiency and irrigation uniformity in front of the border can be more effectively controlled by regulating flow rate than by stopping distance and stopping time.Therefore,it is recommended to control the irrigation amount in the automatic controlling border irrigation system that prioritized economy,and to control the flow in the automatic control border irrigation system that pursued precise control.