灌溉方式对土壤水分与灌水量影响的模拟研究

摘要

为明确灌溉方式对土壤水分和灌水量的影响，采用土壤水分概率模型分析了传统灌溉和连续灌溉的土壤水分概率分布特征与土壤平均水分变化规律，研究了灌溉方式对灌水量的影响效应。结果表明：不同灌溉方式的土壤水分概率分布特征差异明显，连续灌溉的土壤水分概率密度极大值出现在 s＝ s*处，传统灌溉的土壤水分概率密度极大值出现在 s＝ sfc处；与传统灌溉方式相比，连续灌溉使土壤平均水分含量保持在相对较低的水平，当降雨发生时，其土壤能够容纳更多的入渗水量。连续灌溉明显减少了土壤水分深层渗漏和地表径流损失水量，显著提高了降雨利用率并降低了灌溉水量，从而提高了农业水资源利用率。%In order to understand the effects of irrigation schemes on soil water content and irrigation amount ,a soil water probability model was employed to simulate the characteristics of soil water probabilistic distribution and the changes of average soil water content under traditional and continuous irrigation .The results indicated that there was a significant distinction of soil water probabilistic distribution for different irrigation schemes ,and the maximum value of probability density function of soil water appeared at s= s* for continuous irrigation ,but s= sfc for traditional irrigation .Compared to traditional irrigation ,continuous irrigation kept the soil water content at a lower level ,thus reducing leakage losses and surface runoff by storing more water into the soil when rainfall happened .Therefore ,continuous irrigation could signifi-cantly increase the use efficiency of agricultural water resources by improving the utilization rate of rainwater and reducing the amount of irrigation water .