渗灌系统在人工再造植被边坡中渗流特征及应用研究

Seepage Features and Applied Research of Infiltrating Irrigation System on Artificially Reclaimed Vegetation Slope

边坡渗灌系统是一种可以应用在人工再造植被地形中的高效率节水灌溉技术。将渗灌系统埋入人工边坡土壤中,合理的渗灌管埋深比例可以在保证灌溉均匀的条件下大大提高节水效率。根据该要求设计了一种新的渗灌数学模型,反映了不同特性土壤中渗灌水分运移的渗流特征,并可以给出优化渗灌管埋深比例的计算公式。以一个埋于60°边坡普通壤土的灌溉系统作为实例,可以计算出渗灌管最佳埋深比例约为44%,上下两层土壤厚度比例大约为4∶5。对再造植被边坡中使用土壤特征、坡度角、给水水头、初始饱和度、渗灌管间距进行对比分析,可以得知随着坡度角的增加,渗灌管最佳埋深位置逐渐加深;而基质吸力更弱的土壤中,渗灌管最佳埋深位置应更浅一些。同时降低给水水头,增加初始含水率以及渗灌管间距都会使渗灌管埋深的最佳位置变得更浅。该灌溉模型可以正确反映了渗流特征,模拟优化边坡渗灌管埋深,使渗灌系统最大程度上节约水资源,具有较好的实用价值。

Slope infiltrating irrigation system is a kind of high efficiency water saving irrigation technique can be applied in artificially reclaimed vegetation terrain. Burying infiltrating irrigation system into artificial slope soil,reasonable infiltrating irrigation pipe buried depth can guarantee water-saving efficiency greatly improved under uniform irrigation conditions. According to the requirements have designed a new kind of infiltrating irrigation mathematical model,can reflect infiltrating irrigation water migration seepage features in different characteristic soils,a computational formula of infiltrating irrigation pipe buried depth ratio optimization can be given. Taking a buried irrigation system in common loam with a 60° slope as an example,computed optimum buried depth ratio is about 44%,thickness ratio of upper and lower two soil layers is about 4∶ 5. To reclaimed vegetation slope soil features,slope angle,feedwater head,initial saturation and infiltrating irrigation pipe interval carried out comparative analysis can know that along with the slope angle increasing,infiltrating irrigation pipe optimum buried depth position gradually deepening; while in matrix suction weaker soil,infiltrating irrigation pipe optimum buried depth position should be shallower. Meanwhile,lowering down feedwater head,increasing initial moisture content and infiltrating irrigation pipe interval will make the depth furthermore shallower. The irrigation model can reflect seepage features,simulate optimized slope infiltrating irrigation pipe optimum buried depth correctly,and make the infiltrating irrigation system saving water resources to a maximum extent with better practical value.