HYPROP系统与快速离心法联合测定土壤水分特征曲线

Using HYPROP System and Centrifugal Method to Measure Soil Water Characteristic Curve

针对3种供试土壤,利用HYPROP系统与快速离心法分别测定了土壤在低吸力(800hPa以下)和高吸力(1×103～15×103 hPa)范围内土壤吸力和含水率的关系,并联合2种方法的测定结果,采用van Genuchten(1980)-Mualem拟合得到了土壤水分特征曲线的经验参数。其中快速离心法中用对数函数拟合了转速与压缩量间的关系,并利用压缩量对不同转速下的土壤吸力进行了修正。研究结果表明,利用HYPROP系统与快速离心法联合测定土水特征曲线,克服了HYPROP系统不能测定高吸力范围土壤水分特征曲线以及快速离心法对低吸力范围测定精度较差的缺点,在较短时间内可以准确测定低吸力和高吸力范围内的土壤水分特征曲线。土壤质地及孔隙分布是影响土壤水分特征曲线的主要因素。

The combination of HYPROP system and centrifugal method were used to measure soil water characteristic curve（SWCC）,the parameters of SWCC were evaluated using van Genuchten-Mualem model,a logarithmic function was used to describe the relation between the speed of centrifuge and compressibility of soil,and compressibility of soil was used to amend the relation between the speed of centrifuge and the soil suction.The results showed that ①it was effective and accurate to measure soil water characteristic curve using HYPROP system and centrifugal method jointly;②soil texture and the pore size distribution were the main factors to determine the SWCC.