摘要
为了对比夹层位置和土壤质地变化对层状土入渗特征的影响,选用2种土壤、设置3个夹层位置进行了积水入渗试验.结果表明:在夹层位置为距土表5～10,10～15和20～25 cm这3种情况下,湿润锋到达土层界面的时间和相应的累积入渗量随夹层位置和夹层土壤质地的差异而有所不同.夹层的层位越靠上,湿润锋到达夹层分界线所需要的时间越短,相应的累积入渗量越小.距土表10～15 cm的夹层位置减渗效果最好;夹砂层位置越深,其对入渗率的改变程度越明显,入渗率曲线整体抬高.累积入渗量及湿润锋在水分进入夹层界面前随时间延长而非线性递增,而在水分进入层界面之后趋于线性变化,两者之间具有概化的线性关系,且其线性关系随夹层位置的变化而不同.层状土的土壤含水率分布具有不连续性,同时还受夹层土壤质地的影响.总体上,夹层位置变化对不同质地层状土的入渗有明显影响.
In order to compare the effects of layer positions and soil texture variation on infiltration characteristics of layered soil, two types of soils were selected. Ponded infiltration experiments were conducted at three layer positions. The following results were showed ： At the three layer positions, 5 - 10 cm, 10 - 15 cm and 20 - 25 cm from soil surface, the time when the wetting front reached the layer interface and the corresponding cumulative infiltration were dependent on the layer positions and soil texture in layers. The upper the layer positions, the shorter the time for the wetting front arriving at the layer interface, and the smaller the corresponding cumulative infiltration. Effect of infiltration reduction was the best when layer position was 10 - 15 cm from the soil surface. The deeper the layer position, the more obvious the change in infiltration rate and the higher the infiltration rate curve moved up. Be- fore water entered the layer interface, the cumulative infiltration and wetting front were increased non- linearly with time; however, once the water was in the interface, they raised in a nearly linear relation against time. There was an approximately linear relationship between cumulative infiltration and wetting front, but their relations varied with the layer positions. Soil moisture distributions in layered soils showed a discontinuity, they were also affected by the soil texture in layers. In general, layer positions had obvious effects on infiltration of layered soils.
出处
《排灌机械工程学报》
EI
北大核心
2012年第4期485-490,共6页
Journal of Drainage and Irrigation Machinery Engineering
基金
'十二五'国家科技支撑计划项目(2011BAD29B02)
教育部
国家外国专家局'111'计划项目(B12007)
关键词
夹层土壤
入渗
塿土
砂土
湿润锋
layered soil
infiltration
lou soil
sandy soil
wetting front
