In-Situ Monitoring and Characteristic Analysis of Freezing-Thawing Cycles in a Deep Vadose Zone

摘要: Freeze-thaw cycles play a critical role in affecting ecosystem services arid regions. Monitoring studies of soil temperature and moisture during freeze-thaw process can generate data for research on the coupled movement water, vapor, heat freezing-thawing period which can, turn, provide theoretical guidance rational irrigation practices ecological protection. In this study, changes deep vadose zone were observed by in-situ monitoring from November 2017 to March 2018 Mu Us Desert. The results showed that temperatures gradients largest layers above 100-cm depth, variations decreased with depth. relationship between unfrozen water content be depicted well both empirical models. Due matric potential temperature, flowed deeper towards frozen soil, increasing total at freezing front. vapor flux, was affected mainly diurnal shallow 20-cm layer, its rate gradually depths. divided into three stages: initial stage, downward thawing stage. upward flux contributed formation layer process.