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地面冻结数模型可用于分析、模拟和预测多年冻土的分布,在高纬冻土地区有比较成功的应用.然而Nelson提出的地面冻结数模型并不具备明显的物理意义,往往被归入经验统计范畴.从Ste-fan公式出发,重新推导并详细讨论了地面冻结数模型,使冻结数F=0.5作为多年冻土与季节冻土的分界线具备明确的物理意义.重新推导后的模型增加了一个影响冻土形成和发展过程的并取决于岩土冻融性质的因子E,原Nelson地面冻结数模型可作为E=1时的特例给出.根据青藏高原实测地面温度资料,针对不同的E值,分别模拟了青藏高原的冻土分布情况.对比分析表明,处在多年冻土南北界附近的土壤性质较明显影响了多年冻土在这些区域的分布情况,通过对参数E的调参,可以更好地模拟多年冻土的真实分布情况.
The ground freezing number model can be used to analyze, simulate and predict the distribution of permafrost and has been successfully applied in high latitudes. However, the ground freezing number model proposed by Nelson does not have obvious physical meaning and is usually classified as experience Statistical categories.From the Ste-fan formula, we deduced and discussed the ground freezing number model in detail, so that the frozen number F = 0.5 has clear physical meaning as the dividing line of permafrost and seasonal frozen soil.Re-derivation model increases A factor E that affects the process of formation and development of frozen soil and depends on the nature of rock and soil freeze-thaw, the original Nelson ground freezing number model can be given as a special case when E = 1. According to the measured ground temperature data of Qinghai-Tibet Plateau, E value respectively, and the distribution of permafrost in the Qinghai-Tibet Plateau was simulated.The comparative analysis shows that the soil properties near the north-south boundary of permafrost affect the distribution of permafrost in these regions obviously, , Can better simulate the true distribution of permafrost.