温度及矿化度对土壤持水性能的影响

采用离心机法测定了不同矿化度(1、3、5、10g/L)的NaCl和Na2SO4溶液在不同温度条件下(5、10、20、30℃)对土壤水分特征曲线及其van Genuchten方程参数的影响。结果表明,温度与θs、α均呈现显著的负相关,相关系数分别为-0.83、-0.99;θs与α呈极显著的正相关关系,与n呈极显著的负相关关系,α与n呈极显著的负相关关系。溶液的盐分类型对土壤水分特征曲线的影响在不同的吸力段影响不同,在近饱和段影响比较明显,且对参数α值也有显著影响,其中Na2SO4的影响较NaCl明显。溶液矿化度对土壤水分特征曲线参数(θs,α,n)的影响均不显著。

Effect of Temperature and Degree of Mineralization on the Water-Retention Properties of Soil

In order to study the effects of temperature and degree of mineralization on the water-retention properties of Soil,the soils water characteristic curves were measured by centrifuge and van Genuchten equation parameters were gained by curve fitting with different mineralization degrees(1、 3、 5、 10 g/L) of NaCl and Na2SO4 solutions and different temperatures(5、 10、 20、 30 ℃).The results showed that there were significantly negative correlations between temperature and θs,α,and R were-0.83 and-0.99 respectively.θs showed an extremely significantly positive correlation with α,but an extremely significantly negative correlation with n,and there was an extremely significant negative correlation between α and n.The influence of different salts on soil water characteristic curve was different under different water suction conditions,and was more obvious in nearly saturated section than far saturated section,and had significant effects on the value of α(p<0.01).The effect of Na2SO4 on α was obvious than the NaCl.The influences of degree of mineralization on the parameters(θs,α,n) of soil water characteristic were not significant(p>0.05).