亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

This paper discovers the soil temperature and meteorological factors’ impact on soil thermal status in seasonal frozen under the condition of snow cover. We measured the soil temperature in the depth of 5, 10, 20, 40, 60, 100, 140cm under the condition of bare land, nature snow cover, snow compressed and snow thickened. Based on field experimental data, grey correlation analysis was used to select the main meteorological factors affecting the soil thermal conditions and then we calculated the correlation between soil temperature and meteorological factors. Results shows that the existence of snow hampers the energy exchange between soil and environment, causes the difference between the soil temperature and freezedthawing process, and with the increase of depth of the snow cover, soil freezing and thawing date will be delayed, the soil temperature will be relatively stable at a high level. Meanwhile, the difference of temperature between soil and atmosphere will enlarge. In the process of freezing and thawing, environment temperature is the main controlling factor of soil temperature; snow cover makes the correlation between meteorological factors and soil temperature weaker.