基于SISM模型和畦灌技术的冬小麦最小灌水定额研究

Minimum Irrigation Quota of Winter Wheat Based on SISM Model and Border Irrigation Technology

为确定满足畦灌技术约束下的冬小麦最小灌水定额,采用地面灌溉水流运动模拟模型SISM,结合华北地区畦灌现状,考虑畦田长度、坡度、田面标准差、微地形空间分布差异及入畦单宽流量等要素,设计53088种畦灌技术要素组合,以地面灌溉水流覆盖整个田块和最小灌水深度Zmin>0为控制条件,对不同技术要素组合下的灌水过程进行模拟,分析畦灌技术要素和灌水性能指标值的对应关系,结合畦灌数值模拟试验结果,提出3种代表性畦田长度(50、100、150 m)下田面标准差、坡度、入畦单宽流量等畦灌要素的建议范围。在不考虑畦田布置优化方案的条件下,3种代表性畦长畦灌最小灌水定额不宜低于84、117、148 mm;在地面灌溉技术及畦田布置方案优化的条件下,3种代表性畦长畦灌最小灌水定额不宜低于71、75、79 mm。

The irrigation process under different combinations of border irrigation technology elements was simulated to obtain the corresponding border irrigation performance index values,and determine the minimum irrigation quota under different combinations of border irrigation technology elements in North China Plain.Combined with the current situation of border irrigation in North China Plain,the border length,slope,field leveling accuracy,micro-topography spatial distribution difference and border unit width flow were taken into account,including 53088 border irrigation technology elements in total.The whole field was covered with the surface irrigation water,the minimum irrigation depth Zmin>0 was taken as the control condition,and the SISM model was taken to simulate the irrigation process under the combination of different technology elements,analyze the corresponding relationship between border irrigation technology elements and irrigation performance index values,and by combining with the test results of border irrigation numerical simulation and relevant regulations of surface irrigation,the recommended range of border irrigation elements under three representative lengths of border field 50 m,100 m and 150 m(such as field leveling accuracy Sd,slope Sp,and unit width flow q)was proposed.The minimum irrigation quota of three representative border lengths should not be lower than 84 mm,117 mm and 148 mm under normal conditions,and the minimum irrigation quota of three representative border lengths should not be lower than 71 mm,75 mm,and 79 mm under the optimized conditions.