Abstract:

The study on soil temperature distribution in the whole transition zone from the alpine zone to the edge of Zhungeer Basin in the middle Tianshan fault zone is helpful to understand the characteristics of soil environment in arid area, so as to provide basis for land use and agricultural production. In this paper, the daily observation data of soil temperature at each layer of six meteorological stations in the middle Tianshan fault zone of Xinjiang in 2005 to 2020 were selected. The statistical method was used to analyze the variation characteristics of soil temperature with altitude at different topographies and depths. The results showed that the variation of soil temperature on the northern slope of the middle Tianshan Mountain was enhanced with the decrease of altitude. The annual temperature difference of the highest temperature and lowest temperature in four different terrains was larger in the shallow layer than that in the deep layer, and the occurrence time of the highest temperature in each layer was gradually delayed; in a year, the average daily soil temperature curve at different altitudes of 0-20 cm in the study area was roughly a cosine function curve, and the soil temperature at 320 cm depth was basically a sine function distribution, which was about 3 months later than the maximum and minimum ground temperature of 0-20 cm. The soil temperature in the study area increased first and then decreased with the decrease of altitude. In the range of 3539 to 600 m above sea level, the soil temperature decreased with the increase of altitude. In the range of 600 to 441 m, the soil temperature decreased with the decrease of altitude. 0-20 cm was the active layer of soil temperature change, 40 cm depth of soil temperature could be called the transition layer, 320 cm depth was called the soil temperature stable layer, 80-160 cm was called the soil temperature secondary stable layer.

Key words: north slope of middle Tianshan Mountain, altitude, soil temperature, distribution characteristics