摘要
多种土壤野外及室内实测的结果,说明土壤水运动的滞后现象存在于一切土壤中,但相对而言,土壤质地愈轻,滞后的影响愈明显。砂土的最大滞后变幅可达20%(体积含水率,下同),粉砂壤土为11.1%,而亚粘土则仅有3%左右。当前较通用的考虑滞后影响的有四种计算方法:区域理论算法、线性算法、扦值法和解析表达式法。它们各有其适用条件,经过对比及实验验证,说明线性算法具有简单、易于进行计算处理,且在高阶扫描的计算中仍能保证足够精度的优点,是值得推荐的一种算法。作者针对土壤水滞后现象的研究现状,提出了在实际计算中如何考虑滞后影响的建议。
Both field and laboratory experiments of different soils show that the hysteresis phenomenon of soil water movement existed in ahnost all kinds of soils. However, it has a greater effect on water flow in light soils. The maximum soil water content due to hystersis was about 20%(vol./vol.) in medium and find sandy soils, 11.1% in silty soil, but only 3% in, silty clayey Joam.At present, four different approaches——domain theory algorithm, linear algorithm, interpolation algorithm and analytical algorithm are commonly introduced in considering hysteresis in numerical simulation of water fiow. It is shown that the linear algorithm has the advantages of simplicity, ease and sufficient accuracy, parficularly in the higher order scanning process. the light of carrent research status, proposals for considering the effect of hysteresis on soil water movement in practical computation are also given.
出处
《土壤学报》
CAS
CSCD
北大核心
1993年第2期210-216,共7页
Acta Pedologica Sinica
基金
水利水电科学基金
博士点基金
关键词
土壤水分
运动
滞后效应
Effect of hySteresis
Main drying
Main wetting
Higher order scanning
