论文部分内容阅读
土壤斥水性(SWR)阻碍入渗及再分布过程.虽然斥水土壤在世界广泛存在,但其产生机理并不明确.本文采用滴水穿透时间(WDPT)法、酒精摩尔浓度(MED)法和接触角(θ)法测定了新疆玛纳斯河流域典型土壤的SWR指标,其中θ的测定采用高度法和质量法.对WDPT是否受烘干及不同容重的影响进行对比,探讨各SWR指标之间的联系,并分析了SWR的关键理化性质影响因子,探讨土壤斥水的机理和原因.结果表明:高容重土壤的WDPT值更大,烘干土壤的WDPT值比风干土壤大;3种SWR指标(WDPT、MED及θ)之间有一定的相关关系,但MED与θ的相关性并不明显,表明各SWR指标之间虽有一定联系,但表征方面具有差异性;采用高度法和质量法测量水与土壤的θ值时,高度法的θ值大于质量法,高度法之间重复差异小于质量法;使用正辛烷作为参比溶液测量水与土壤的θ值时,其重复的差异较小,低于无水乙醇;在多种理化性质中,黏粒含量比其他土壤属性更显著地影响WDPT和θ;[K~+]、[Na~+]均与θ呈正相关;蒙脱石含量与WDPT、MED呈负相关.综上,土壤SWR的测定方法中,WDPT法操作简单但易受影响;MED法缩短了入渗时间但试验过程耗时;接触角法操作复杂,结果相对精确,采用正辛烷作为参比溶液的高度法更可靠.建议采用多种指标综合表征土壤斥水性.
Soil water repellency (SWR) hinders infiltration and redistribution process.While water-repellent soils are widespread in the world, its mechanism is not clear.In this paper, WDPT, MED and The contact angle (θ) method was used to determine the SWR index of typical soil in the Manas River basin, Xinjiang, and the height and mass method were used to determine the θ.The influence of WDPT on drying and different bulk density were compared to explore the SWR index And analyzed the key factors influencing the physical and chemical properties of SWR, and discussed the mechanism and cause of soil water repellency.The results showed that the WDPT value of soil with high bulk density was larger, the WDPT value of dried soil was larger than that of soil with dry soil, and the three kinds of SWR (WDPT, MED and θ). However, the correlation between MED and θ is not obvious, indicating that although there is a certain relationship between the SWR indexes, there are differences in characterization. Using the method of height and quality When measuring the θ value of water and soil, the value of θ of the height method is larger than that of the mass method, and the difference between the height methods is less than that of the mass method. When n-octane is used as the reference solution to measure the θ value of water and soil, the repeated difference Smaller, lower than absolute ethanol; in many ways Compared with other soil properties, clay content significantly affects WDPT and θ; [K ~ +] and [Na ~ +] are positively correlated with θ, and the content of montmorillonite is negatively correlated with WDPT and MED. , The determination of soil SWR method, WDPT method is simple but vulnerable to influence; MED method to shorten the infiltration time but the test time-consuming; contact angle method is complex and the results are relatively accurate, the use of n-octane as reference solution height Method is more reliable.It is suggested to use a variety of indicators to comprehensively characterize soil water repellency.