摘要
近40年来,黄河源区地温长期处于增温状态,多年冻土出现表层融化。冻土退化后,土壤含水率减少,导致寒区径流的变化。所以研究冻土为寒区水资源估算提供了重要的依据。利用土壤水分迁移方程和热传导方程,采用中心差分格式并在一定假设前提下建立起冻土水热耦合迁移数学模型。对黄河源区站点的冻融深度进行模拟,结果表明:计算值和近2 a冻土的上、下限实测值吻合较好。由此表明采用的数学模型和数值方法是合理、可信的,在此基础上讨论了土壤冻融过程的一般规律。
In the recent 40 years, ground temperature has been increasing in the source region of the Yellow River, as a result, permafrost table drops down. After the degradation of permafrost, soil moisture decreases which leads to the change of the frozen zones＇ runoff. So the study on the frozen soil will provide the important foundation to estimate the water resources in frozen zones. By using the equation regularity of moisture movement and soil thermal conductive and adopting central scheme, the mathematical model for solving the problem of coupled moisture and heat transfer during soil freezing is established with some assumption, and the soil freeze-thaw depth in the source region of the Yellow River is simulated . The measured data agree well with the theoretical prediction based on the proposed model and solved by finite difference method. In this paper, by using heat and water coupled equations, the annual variations of soil freezing and thawing in the station of frozen soil are simulated. The law of annual variations of frozen depth is analyzed. Additionally, the temperature factor affecting frozen depth is also analyzed.
出处
《黑龙江水专学报》
2009年第3期100-104,共5页
Journal of Heilongjiang Hydraulic Engineering College
基金
国家自然科学基金重点项目(40830639)
关键词
黄河源区
数值模拟
土壤冻融过程
水热耦合迁移
the source region of the Yellow River
numerical simulation
the freezing-thawing process of soil
coupled moisture and heat transfer
