南方冰冻交通危险度预警评估技术

 通过对南方地区影响公路交通的冰冻过程确定，利用灰色关联方法，构建基于过程日平均降水量、日平均气温、降水持续天数、冰冻持续天数等4个因子指标量的冰冻交通危险度预警模型。为了检验危险度预警模型的可信度及预警效果，采用2016年1月21-25日中国“超级寒潮”事件南方地区地面站实况资料和实时公路阻断灾情数据，进行冰冻交通危险度预警等级结果与公路阻断灾情的对比分析。结果表明，预警最高等级（5级）区域内极高交通风险路段与区域内实际发生公路阻断路段呈现非常好的吻合关系；随着预警等级升高，更大比例的公路阻断发生在预警区域内。高速、国道、省道等不同等级道路阻断里程百分比都随预警等级的增加而呈现上升趋势，且国家高速阻断比例在等级较高时表现突出，省级道路阻断比例在等级较低时开始凸显。体现出预警模型不仅对实际公路阻断灾情有很好的关联性，而且较好地反映了模型中不同等级道路对冰冻灾害响应的区别，对公路阻断灾情的预判起到很好指示作用，为交通运行风险控制提供参考。

A study of early warning technique of hazard degree from freezing processes in southern road traffic

With the definition of the freezing process under the influence of the road traffic, an early warning model is built based on the gray correlation method for monitoring the hazard from the freezing processes in the road traffic in the south area. For each process, the four indexes, including the average daily precipitation and air temperature, the overall rainy days and frozen days, contain the metric to quantify its hazard degree. With the analysis of the meteorological factors and the road-blocking disaster of the freezing process in south China during January 21-25, 2016, it is concluded that the extremely high risk area (Grade 5) and the road block area have a very good coincidence relationship, and as the level of the hazard degree rises, the ratio of the hit road block rises accordingly. The relationship is applicable for the state highways, the national highways and the provincial highways, while the peak value of the ratio is at the high hazard degree for the state highways but it is at a lower hazard degree for the provincial highways. These characteristics show that the early warning model proposed in this paper not only gives a good indication, but also discriminates the roads of different grades, to provide a sound reference for the traffic risk control.