科尔沁沙坨地-草甸地冻融期地温与最大冻结深度的变化规律

目的]探究科尔沁沙坨地—草甸地土壤温度与冻结深度的变化规律,为合理指导该区农工生产和建设提供支持。方法]基于2007—2015年冻融期人工观测数据,对比分析科尔沁沙坨地与草甸地冻融期多年土壤温度与最大冻结深度变化规律。结果]研究区100cm处沙坨地与草甸地多年土壤温度的标准差变化规律基本一致,草甸地要小于沙坨地,但融解后期由于草甸地融解期历时较长,其标准差大于沙坨地;同时考虑土壤温度和土壤水分对最大冻结深度的影响时,沙坨地在200cm处和草甸地在140cm处的R2分别为0.959和0.788。结论]研究区内沙坨地先冻结与先融解,沙坨地最大冻结深度较草甸地深,同时考虑土壤温度与土壤水分的最大冻结深度的拟合优度最好,沙坨地与草甸地中最大冻结深度与土壤温度和土壤水分均呈负相关关系。

Change Rules of Soil Temperature and Maximum Freezing Depth During Freezing-thawing Period in Horqin Sand and Meadow Land

Objective] The changes of soil temperature and maximum frozen depth in Horqin sand and meadow land were to provide support for reasonable guide of the agricultural production and construction.Methods] Based on the artificial observation data from 2007 to 2015 during the freezing and thawing period, variability of soil temperature and maximum frozen depth in Horqin sand and meadow land were analyzed and compared during the freezing-thawing period.Results] Changes of the standard deviation of soil temperature in sand and meadow land at 100 cm were basically the same, and values of meadow land were less than the ones of sand land. But the later melting period of meadow land lasted longer time, whereby its standard deviation was greater than the one of sand. Considering the impact of soil temperature and soil moisture on maximum frozen depth at the same time, the determinant coefficient of R² at depth of 200 cm in sand and 140 cm in meadow land were 0.959 and 0.788, respectively.Conclusion] Sand land froze and melted in advance in the study area, maximum frozen depth in sand was deeper than the one of meadow land. If soil temperature and soil moisture were considered at the same time, correlation coefficient to the maximum frozen depth was greater than the corresponding value of only single variable included. Soil temperature and soil moisture were negative correlated with the maximum frozen depth in sand and meadow land.