青藏高原中部冻土环境下土壤水分监测

利用2006-2007年冬季青藏高原中部那曲布交(BJ)站测量的土壤水势、未冻水含量以及土壤温度资料, 分析了冻土环境下土壤水势、 未冻水含量和土壤温度三者的关系. 结果表明: 青藏高原中部冻土环境下, 土壤水势随着土壤温度及未冻水含量的变化而变化, 土壤质地是决定土壤水势的一个重要因素;未冻水含量与土壤温度保持着动态平衡, 随着土壤温度的降低, 未冻水含量减小, 土壤水势也随之减小;20 cm处砂质壤土的未冻水含量与土壤温度呈指数函数关系, 土壤水势与未冻水含量可用二次曲线拟合, 土壤水势与土壤温度呈指数函数关系;Clausius-Clapeyron方程对于计算青藏高原中部非饱和冻土水势存在局限性.

Monitoring Soil Water in Frozen Soil on the Central Tibetan Plateau

Soil water potential in frozen soil was continuously monitored over an entire winter period using pF-Meter along with soil temperature, unfrozen water content and air temperature on the central Tibetan Plateau. The relationship between the soil water potential, soil temperature and unfrozen water content were analyzed. It is found that: the soil water potential varies with the soil temperature and unfrozen water content in frozen soil;the soil texture is an import factor in determining soil water potential in frozen soil;a dynamic balance is kept between the unfrozen water content and the soil temperature in the frozen soil;the soil water potential decreases with the decrease of unfrozen water content and soil temperature.