水平畦田微地形空间变异性对灌溉系统的影响

基于畦灌数值模拟试验设计,在考虑随机生成的畦面相对高程最小样本容量值的基础上,借助数值模拟手段分析微地形起伏幅度Sd及其相应的起伏位置空间分布差异对宽畦灌溉系统的影响,以评价微地形空间变异性对畦灌质量的作用。结果表明,微地形起伏幅度增大对水平畦灌性能的影响较为显著,它使平均深灌水深度明显增大,灌溉效率和灌水均匀度显著降低。另一方面,微地形起伏位置空间分布差异对水平畦灌性能的影响取决于相应的微地形起伏幅度,Sd≤4cm下的微地形起伏位置空间分布差异对畦灌性能影响的程度较小,而Sd>4cm后的影响程度逐渐增加。

Influence of microtopography spatial variability on horizontal border irrigation system

The influences of microtopography undulation degree S_d and the discrepancy of undulation location distribution on horizontal border irrigation system were analyzed by using numerical experiments for evaluating the effect of microtopograhpy spatial variability on irrigation quality.The result shows that microtopography undulation degree obviously affects the irrigation performance.When S_d is larger,the average irrigation water depth increases and corresponding irrigation application efficiency as well as irrigation uniformity will be obviously reduced.The effect of discrepancy of undulation distribution on irrigation performance is dependent upon the microtopography undulation degree.When S_d is less than 4cm,this effect is relatively small;while S_d is more than 4cm,the influence degree will sharply increase.