| چکیده انگلیسی مقاله |
Background and purpose: Road accidents are one of the main causes of mortality and severe financial and physical injuries. There are many factors in their occurrence. One of these factors is the environmental and climate variables. One of the most important atmospheric hazards that causes bad conditions for drivers, is limitation of field of vision, which occurs due to falling snow and rain, occurrence of fog and storm with dust. Usually, falling snow and subsequently frost, in comparison with the occurrence of the fog, create more risks for drivers, With the difference that the occurrence of snow and ice can be predicted with probability, and even if necessary, they can be controlled with equipment such as grenades and sprayers. But the fog is from atmospheric disasters, which is very difficult to predict, due to the time and place variations of this atmospheric phenomenon. Fog is one of the atmospheric phenomena that directly and immediately affects transport safety, Therefore, the purpose of this study is to evaluate the probability of occurrence of visual limitation in East and West Azarbaijan provinces in order to manage safety and reduce road accidents. Method: In this study, the weather data related to the field of vision during the 20 years statistical period (1991-2010) and for the 13 synoptic stations located in the study area were obtained from the Meteorological Organization of the country, in order to investigate and study the occurrence probability of vision limitation and its effect on transport safety. Then, using statistical methods was studied days with a vision of less than 3000 meters in these stations and were extracted the probabilities of the relevant occurrence. Findings: The results of this study showed that the most probability occurrence of the field of vision of less than 3000 meters occurse in December, january and February months with a probability of 10 to 40 percent, and the least probability of occurrence occurs in the months of July, August and September with a probability of occurrence of 0 to 5 percent. In general, the most occurrence probability of the field of vision of less than 3000 meters during the year is related to Tabriz and Sardasht stations, and the least occurrence probability is related to the stations of Mianeh, Jolfa and Takab. Conclusion: given that the limitation of vision, especially due to the occurrence of heavy fog, is associated with a reduction in traffic volume speed on the road and an increased risk of road accidents, It is suggested that, while increasing the number of meteorological stations on the mountainous and foggy roads route of the country, It is recommended to prepare a national comprehensive Atlas of climate parameters affecting road transport. |