Abstract:Relying on the Tianshan Forest Ecosystem Positioning Station, fixed observation areas were set in the typical regional forest and grassland, and the snow cover characteristics (snow density, liquid water content and snow temperature), runoff yield, erosion amount and conventional meteorological indicators of the forest and grassland were monitored during the snow melting period, and the snow melting process of forest and grassland was compared and analyzed. The results showed that the interception of snowfall by canopy of forest was about 56.8% during snow melting period, the average snow cover depth of grassland was 2.5 times that of forest. The decline rate of snow depth in the forest was higher than that in grassland at the late stage of snowmelt runoff, which due to the snow intercepted by the canopy fell under gravity. The producing time of snowmelt runoff was earlier in forest than that in grassland, and the variation of snow cover density and liquid water content in forest and grassland was similar during the runoff period, and the peak value was in the middle layer of snow, however, the average snow density and average liquid water content of the snow in the forest were 0.48 g/cm3 and 0.61%, which were both greater than those in the grassland (0.29 g/cm3and 0.52%). The peak value of the snow temperature in the forest was on the surface of the snow, while that in the grassland was on the bottom of the snow, the average snow temperature of the forest was -0.032℃, which was lower than the grassland by 0.046℃. And the liquid water content of the snow was significantly positively correlated with the temperature of the snow layer (r=0.611, p<0.05). The runoff yield and surface erosion of grassland runoff plot were twice and six times as much as those of forest. The percentage of surface erosion of forest and grassland to total runoff was 0.21% and 0.71%, respectively. The scouring effect of snowmelt runoff to the surface in forest is smaller than that in the grassland during the process of snowmelt runoff production, which reflected the soil consolidation of the forest. The research results provided theoretical basis and data basis for small-scale study of snow melting process.