【摘要】 利用2003年10月~2004年9月青藏高原北部可可西里(QT01)、北麓河(QT02)、开心岭(QT05)、通天河(QT06)等地区一个完整的冻融循环周期活动层土壤热通量、土壤温度、土壤水分等观测资料,通过数值方法计算高原北部活动层土壤导热率,分析高原北部活动层表层土壤热通量及导热率的变化特征。结果显示,研究区域活动层土壤导热率具有明显的季节变化特点,表现为冷季小、暖季大;导热率随土壤容重的增大而增大,随下垫面植被盖度的增大而减小,高寒草甸土的土壤导热率小于高寒草原土的导热率;细粒土壤、较小未冻水含量及较低的饱和度是造成冷季土壤导热率较小的原因;月平均导热率可表示为地气温差及水气压等常规气象资料的函数。更多还原

【Abstract】 Using the data of soil temperature gradient,soil moisture and soil heat flux from Oct.2003 to Sep.2004,soil thermal conductivity at the topsoil of active layer in northern Qinghai-Tibetan Plateau were calculated by numerical method.And the features of topsoil’s heat flux and thermal conductivity were analyzed.The results show that the soil thermal conductivity reveals obvious seasonal variation characteristics with small values in cold season while lager values in warm season.Thermal conductivity increases with the increase of soil bulk density,while deceases with the decrease of underlying surface vegetation coverage.For different underlying soil type,thermal conductivity of alpine steppe is greater than that of alpine meadow.Low thermal conductivity in cold season is attributed to fine-grained soil,the smaller unfrozen water content and lower degree of saturation.Monthly average thermal conductivity can be expressed as the function of the temperature difference of surface and air and the water pressure.更多还原