Analysis Of The Effect Of Snow On Soil Temperature And Humidity Based On Experiment

Snow cover is widely distributed on the land surface.It is the most common and important upper boundary condition for farmland soil in Northeast China.Due to the special physical properties of snow cover,it affects the energy balance on the land surface and the hydrothermal conditions of the soil,which has a huge impact on the climate and natural environment.In this paper,Harbin,which is the second largest stable snow-covered area,is used as the research area.Two outdoor observation experiments are performed.The Delta TRAK probe thermometer is used to measure Surface temperature under snow at different depths,snow surface temperature,and bare land temperature.Continuously observe and compare the land surface temperature under different depths of snow,snow surface temperature,and bare land surface temperature,and analyze the temperature effects of snow at different depths.At the same time,the soil temperature and humidity monitoring system is used to monitor the deep soil temperature and soil humidity(soil liquid moisture content)under bare land and snow at different depths.recording.The results show that:(1)Snow cover has different effects on surface soil temperature in different seasons.In winter,the surface temperature under snow is significantly different from the bare surface temperature.The snow has a thermal insulation effect on the surface.The surface temperature under the snow is greater than the bare land at any time of the day,and its daily variation characteristics are the same as the bare land.The time to reach the highest temperature is 2 hours behind the bare land;The snow cover insulation effect increases with snow depth,The snow surface has a linear relationship with the bare land temperature difference and snow depth.For every 5 cm increase in snow depth,the surface temperature increases by 2.985℃,and the snow depth exceeded 20 cm had no significant difference in the thermal insulation effect on the surface temperature.In spring,the surface temperature under snow is lower than that of bare land during the day,and the heat preservation effect is at night.The overall effect of the day is cooling,which is 1.12℃ lower than that of bare land.The change in snow depth has no significant effect on the temperature.(2)Different seasons of snow cover have different effects on deep soil temperature.Snow cover has a thermal insulation effect on deep soil in winter.With the increase of snow depth,the soil temperature also rises.For every 10 cm of snow depth,the overall soil temperature increases by 0.872℃.The temperature of 5cm,15 cm,25cm,and 35 cm soil layers respectively increase 0.865℃,0.719℃,0.565℃,0.425℃;Snow cover has different effects on soil temperature at different depths in spring.The effect of snow cover on the temperature of 5cm soil layer is that the temperature of the soil under the snow cover during the day is lower than that of bare land.Effect,the soil temperature under the snow at night is higher than the bare land,which shows the insulation effect,and the overall performance is the cooling effect,which is 0.77℃ lower than the bare land on average;The 15 cm,25cm,and 35 cm soil layers under the snow are higher than the bare ground at 1.26℃,1.72℃,and 1.81℃,respectively.(3)Melting snow has a significant effect on soil moisture.The greater the snow depth,the faster the melting rate.For every 10 cm increase in snow depth,the snow melting rate increases by 0.297cm/d.The vertical change of soil moisture under snow cover is gradually decreasing from the surface layer to the bottom layer,but the opposite is true for bare land.The greater the snow depth,the greater the soil humidity.For every 10 cm increase in snow depth,the overall soil humidity increases by 2.555%,and the soil moisture at 5cm,15 cm,25cm,and 35 cm increases by 2.115%,3.141%,1.889%,and 1.898%.