午夜欧美大片免费观看,欧美激情综合五月色丁香,亚洲日本在线视频观看,午夜精品福利在线

The temporal and spatial distributions of road icing are analyzed on the basis of hourly meteorological data from automatic weather stations along the main road over Qinghai from 2004 to 2012, and the linear relationship between road icing and surface/air temperature, snow depth, and maximum temperature is discussed. The results show that road icing gradually reduced from southeast to northwest and mainly occurred from January to April. Analyses suggest that there exists a robust linear relationship between surface and air temperature, snow depth, and maximum ground temperature; therefore, surface temperature and snow depth can be predicted based on those linear models, which can be used for the warning of road icing. The impact of road icing on traffic safty, deponding on the duration of road icing, are divided into 4 grades: extremely severe, serious, relatively serious, and slightly icing.