不同灌溉条件对黄河下游引黄灌区作物水分关系的影响

Effects of Different Irrigation Systems on the Relationship between Crops and Water in the Irrigation Districts along the Lower Reaches of the Yellow River

在田间试验验证的基础上,利用SWAT2000模型对黄河下游引黄灌区冬小麦、夏玉米在不同灌溉条件下产量、耗水量以及水分利用效率等的时空变化进行了模拟,结果表明,冬小麦缺水情况比较严重,夏玉米生育期降水量基本能满足其耗水量的需求。灌溉对提高作物产量以及耗水量有很大的影响,然而随着灌水量的增加,作物产量以及耗水量增加的幅度并不大。在不考虑氮、磷等对作物生长的影响下,作物产量、耗水量以及水分利用效率多年来在区域上的变化并不明显,雨养条件下区域变异性最大。不同引黄灌区不同灌溉条件下作物产量、耗水量以及水分利用效率的变化幅度不一样。

SWAT2000 was calibrated and validated based on the field experiments and was used to simulate the temporal and spatial variation of grain yield,actual ET and water use efficiency（WUE） of winter wheat and summer maize under full irrigation,scheduled irrigation,and no irrigation in the irrigation districts along the lower reaches of the Yellow River.From the simulated results,it can be seen that winter wheat was seriously lack of water and precipitation during summer maize can almost satisfy the actual ET need of summer maize.Irrigation had much influence on the increase of grain yield and actual ET,while with the increasing of irrigation amount,the increase range of grain yield and actual ET of winter wheat and summer maize is not large.WUE of winter wheat would reach a maximum value with the increase of actual ET and WUE of summer maize would reach a fixed value with the increase of actual ET.Without consideration the effect of N,P on the crop growth,the spatial variability of grain yield and actual ET of different crops among different irrigation districts is not obvious.The change of grain yield,actual ET and WUE of winter wheat and summer maize in different irrigation districts under different irrigation systems was different.