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地温年变化深度的准确判断对于多年冻土发育特征评估、寒区冻土模式下边界深度的确定具有重要意义.通过对青藏高原地区典型钻孔地温数据进行分析,初步揭示了多年冻土地温年变化深度的变化规律及其影响因素,并提出一种简化了地表和活动层状态影响的地温年变化深度估算方法.结果表明:研究区低温冻土的地温年变化深度平均值比高温冻土大4.6 m,随着冻土温度升高,地温年变化深度基本上呈减小趋势,部分低温冻土钻孔由于土层含水率过高导致地温年变化深度相对较小;由于活动层水热动态和冻融过程的影响,地温年变化深度与浅层(0.5 m)温度年较差相关性不显著,而与多年冻土上限附近温度年较差的大小呈显著正相关关系;地层介质的热扩散率差异是导致地温年变化深度区域差异和变化的主要原因,土层含水率、温度、质地以及水的相态是影响地层热物理性质重要因素.
The accurate judgment of the annual depth of the geothermal temperature is of great significance for the evaluation of the developmental features of the permafrost and the determination of the depth of the boundary under the frozen soil permafrost region.Based on the analysis of typical borehole temperature data in Qinghai-Tibet Plateau, The change rule of depth and its influencing factors are proposed and a method to estimate the annual variation of geothermal temperature which simplifies the influence of the surface and active layer status is proposed.The results show that the average depth change of geothermal temperature in the permafrost area is larger than that of the permafrost 4.6 m. As the permafrost temperature increases, the annual variation depth of ground temperature basically shows a decreasing trend. Due to the excessively high soil moisture content in some of the permafrost bores, the depth of ground temperature changes relatively slowly. Due to the hydrothermal dynamic state And the influence of freeze-thaw process, the annual variation depth of geothermal temperature is not significantly related to the annual temperature difference of shallow layer (0.5 m), but positively correlated with the poor annual temperature of upper permafrost boundary. The heat of formation medium Differences in diffusivity are the main causes of regional differences and changes in the depth of geothermal annual variations. Soil moisture content, temperature, texture, Rationality is an important factor.