Abstract
In this paper, the ground temperatures and the unfrozen water contents estimated from Time Domain Reflectometry (TDR) measurements at experimental site A(cultivated land) and C (salinized land) , were applied to analyze the ground freezing in Hetao Irrigation District, Inner Mongolia of China. Based on the different transportation status of unfrozen water, the frozen soils were divided into extensively frozen and partially frozen layer. In extensively frozen layer the unfrozen water content is kept as constant without remarkable changes, whereas below this layer, the unfrozen water content changed abruptly, the layer is referred partially frozen layer. It is found the isotherms of —1.2 and — 2.1°C are the boundary temperatures between extensively and partially frozen layers at site A and C, respectively. The estimated unfrozen water content showed the partially frozen layers still existed in the depth of 0.70〜0.90 m at the end of April.
