冻融过程黑土2m土体固液态水分含量动态特征

Study on the dynamic characteristics of solid and liquid water in the process of freezing-thawing in black soil

应用中子仪-TDR联合测定法监测海伦站冻融过程中黑土固液态水分含量的动态特征结果表明:冻结过程,2m土体水分含量增加73.7 mm,约占全年降水总量的13.4%,上层土体水分含量的增加是下层土体水分在温度梯度驱动下向上层迁移造成的。固态水含量是土壤温度和土体含水量综合作用的结果,2 m土体固态水贮量最大值出现在2月下旬至3月初,约占2 m土体总水贮量的60%;液态水含量随冻结时间推移逐渐减少,直至达到稳定的冻结状态,液态水最小含量约占2 m土体总水贮量的40%。

Migration of solid and liquid water in black soil as well as soil temperature are studied with the method of Neutron Probe-TDR during the soil freezing-thawing process. The results shows that the soil water content in the upper-layer increases 73.7 mm that accountes for 13.4% of annul rainfall, as a result of vertical water transportation from downside soil profile of 2 m depth in the freezing period. The content of solid water is driven by the soil temperature and content and the total water content arrives at a peak of 60 % of total water during late February and early March. The content of liquid water decreases in the process, in which the lowest amount accounted for 40 % of total water in the steady freezing process.