供水压力对地下点源水分入渗过程的影响研究

根据大田地埋地下滴灌毛管单孔入渗试验资料,分析了供水压力对水分入渗过程以及入渗模型参数的影响.研究结果表明,供水压力对地下点源入渗过程具有明显的影响,累积入渗量随供水压力的增大而增加,压力势是影响土壤中水分运动的主导势,其相对稳定入渗率与供水压力所产生的压力势梯度直接相关;供水压力与考斯加可夫人渗模型人渗系数有一定的相关关系,而与入渗指数相关性差.研究成果对土壤水分运动理论的研究和地下滴灌灌水技术参数的确定具有一定的参考价值.

Research on influence of feed-water pressure on water infiltration process of subsurface point source

Based on field testing data of subsurface infiltration using dripping duct with single-hole conduit,the author analyzes the influence of feed-water pressure on water infiltration process and infiltration model parameters.The testing results indicate that the feed-water pressure has evident influence on water infiltration process of subsurface point source.The cumulated infiltration volume will increase with increasing of the supplied discharge head;the pressure potential is the dominant one influencing movement of soil water; the relative limiting infiltration rate is directly correlative with the pressure potential gradient generated by the feed-water pressure;and the pressure is correlative with the infiltration parameters of Kostiakov infiltration model,but is poorly correlative with the infiltration index.The investigation results will be significant for studying the theory of soil water movement and helpful for determining technical parameters of subsurface drip irrigation.