新疆石河子冻土特征及冻土融化期地温、冻土深度预报研究

为了确保春季播种安全,有必要开展播种期地温的监测和冻土融化深度预报业务。利用新疆农八师冻土气象观测资料,运用相关系数和线性回归方法,分析冻土特征及融化过程中地温变化、深度变化规律,建立春季冻土融化预报模型。结果表明,新疆农八师垦区稳定冻土期在11月中旬至翌年3月下旬,冻土最大深度呈逐年变浅趋势,倾向率为-5.4 cm/10 a;冻土结冻日期推后,倾向率为2.0 d/10 a;冻土化通日期提前,倾向率为-1.5 d/10 a。冻土融化期在3月中旬至4月上旬,冻土融化速率在3.1~4.0 cm/d之间。春季地温与平均气温、冻土融化深度与正积温具有显著的正相关,以此建立了相应的预报模型。10 cm地温预报模型历史回代准确率在96%以上,冻土融化深度预报模型历史回代准确率在94%以上。通过模型可以开展春季地温和土壤融化预报业务。

Frozen Soil Characteristics and Forecasting of Ground Temperature and Frozen Soil Depth During Thawing Period in Shihezi of Xinjiang

To ensure the sowing in spring, it is necessary to carry out the monitoring of ground temperature and the forecasting of frozen soil thawing depth. The meteorological observation data of frozen soil from Shihezi of Xinjiang were utilized and relevant coefficient and linear regression methods were applied to analyze the frozen soil characteristics and the change rule of ground temperature and frozen soil depth in the thawing process, aiming to establish a forecasting model of frozen soil thawing in spring. The results indicate that the stable frozen soil period of Shihezi lasts from the middle ten days of November to the last ten days of March of the next year. The maximum depth of frozen soil tends to become shallow year by year, with the inclination rate of -5.4 cm/10 a; the freezing date of frozen soil is postponed, and the inclination rate is 2.0 d/10 a; the unfreezing date of frozen soil becomes earlier, and the inclination rate is -1.5 d/10 a. The thawing period of frozen soil lasts from the middle ten days of March to the first ten days of April, and the thawing rate of frozen soil is between 3.1-4.0 cm/d. The ground temperature in spring has significantly positive correlations with average temperature, thawing depth of frozen soil and cumulative positive temperature, and the corresponding forecasting models are established. Historical back substitution accuracy rate of the forecasting model of 10 cm ground temperature is over 96%, and historical back substitution accuracy rate of thawing depth forecasting model of frozen soil is over 94%. The forecasting of ground temperature and soil thawing in spring could be carried out through the models.