Abstract:

In order to complete the weather service along Baoji-Tianshui highway, based on the data of weather phenomenon which reducing the visibility, in Tianshui and Baoji national meteorological observation stations from 1961 to 2008, the variation and distribution characteristics of vision obstruction weather phenomena along Baoji-Tianshui highway had been analyzed. The results showed that the sand storm was small probability climatic event. The fog days increased and dust and dust blowing days decreased from east to west. The fog days appeared mainly in October and the frequency was 0.56 days a year in the whole line. The dust and dust blowing appeared mainly in March to May and frequency of dust and dust blowing were 1.4 and 0.7 days a year respectively along the whole line. The disadvantages whether phenomenon for highway decreased in recent years. The fog days decreased with 0.34 days every year in Baoji and 0.01 days every year in Tianshui. Dust days decreased with 0.41 days in Baoji and 1.37 days in Tianshui. There were no dust blowing days since 2002 in Baoji and the phenomenon decreased with 0.37 days every year in Tianshui. The author suggested that people should follow the variation law of weather phenomenon and make measurement to copy the disadvantageous weather condition.