中文摘要：

通过季节冻土区浅层黄土现场温度测试,研究了冬季浅层黄土温度场的变化规律.测试得出：较深处温度变化在冬季过后气温回升时有滞后性;地面温度日变化幅度最大,最大峰值温度出现在下午2时左右,且随着深度增加,出现峰值温度的时间逐渐向后推移;土体温度的日变化随深度的增加逐渐减小,超过30 cm可不考虑温度日变化;给出了非饱和黄土温度场的计算方法,总结阐述适用于渭北旱塬浅层土温度场计算参数的选取,比较了渭北旱塬彬县的计算结果和实测结果,验证了该数值计算方法及参数取值的合理性;进一步模拟渭北旱塬不同气温,讨论了最大冻深的变化规律,并拟合得到了渭北旱塬最大冻深与气温的关系式.

英文摘要：

Through field tests of shallow loess in seasonal frozen ground, temperature field variation in shallow loess is studied. Testing results show that temperature changes of deeper soil lags when temperatures rise after the winter. Temperature variation range of the ground surface is the largest. Maximum peak temperature appears at 14：00 or so. The peak temperature goes gradually backwards in time as the depth increases. The diurnal variation of the soil temperature decreased as the depth increases without con- sidering temperature diurnal variation when the depth is more than 30 cm. A numerical model of temperature of unsaturated loess was given, and parameters of the model which applies to the Weibei upland were summarized. The comparison of calculation results with the tests results of Bin country in the Weibei upland indicates that the numerical calculation method is reasonable. Simulating different air temperatures in the Weibei upland, the changing law of the maximum frost depth was discussed, and the relationship between the maximum frost depth and air temperature in the Weibei upland was obtained by fitting.