微地形及沟断面形状变异性对沟灌性能影响的试验研究

针对沟灌,研究了沟底起伏状况和沟横断面形状的空间变异性对灌水质量的影响。通过分析在河北吴桥开展的棉花沟灌试验数据,描述了灌水沟断面形状和沟底高程二因素的空间分布特征。采用田面平整精度Sd值作为评价沟底高程变化程度的指标,确定其对灌水均匀度和灌水效率的影响;采用断面形状参数p2描述灌水沟断面形状,以p2的标准差反映其空间变异性对地表水流运动和灌水质量的影响。结果表明,灌水均匀度和灌水效率均随沟底高程标准差的增大而减小;水流推进速度随断面形状参数p2标准差的增大而降低,灌水均匀度和灌水效率随p2标准差的增大而减小。因此,微地形和灌水沟断面空间变异性,对灌水均匀度和灌水效率均有显著的影响。

Influences of Spatial Variability of Microtopography and Section Shape on Furrow Irrigation Performance

This paper aims at examining the influences of spatial variability of furrow sole fluctuation and cross-section shape on furrow irrigation performance.A furrow irrigation experiment was conducted in the cotton fields in Wuqiao,Hebei,and observed data were used to describe the spatial distribution characteristics of the cross-section shape and the height of the furrow's bottom.The standard deviation of the surface elevation Sd was used as the index to evaluate the variation degree of the height of the furrow's bottom,and its influence on the distribution uniformity and application efficiency was determined.The influence of spatial variability of cross-section shape on water flow performance and irrigation performance is described using the geometry parameter p2.The results show that the irrigation distribution uniformity and irrigation efficiency decreases when Sd increases,and the flow advance speed decreases when the standard deviation of p2 increases,the distribution uniformity and irrigation efficiency decreases when the standard deviation of p2 increases.It is believed that the spatial variability of microtopography and section shape significantly influences the distribution uniformity and application efficiency.