近56a宁夏高速公路大雾时空特征及风险评价

Characteristic and risk evaluation of heavy fog for highway in Ningxia

基于1960-2015年宁夏大雾逐日观测及大雾发生、结束时间资料,分析了宁夏四条主要高速公路大雾天气事件的时空分布特征。并运用层次分析法和模糊综合评价法,选取平均雾日数、平均持续时间、河网密度、道路密度等10个评价指标,构建宁夏高速公路大雾灾害评估模型,开展风险评价与区划。结果表明:宁夏高速公路9-11月是大雾发生最多的月份,一天中大雾事件高影响时段为02:00-08:00。大雾年平均雾日数特征为京藏高速由中间段向南北逐渐减少;定武高速西段多东段少;福银高速北段少南段多;青银高速北段多东段少。宁夏大雾天气有三个大雾灾害高风险区域中心,即京藏高速银川段、青铜峡段,定武高速中卫段,福银高速固原段。较高风险区域中心位于京藏高速平罗段,定武高速中宁段、盐池段,福银高速固原段附近,其他路段为中等到较低风险区域。

Based on the observed daily fog data over Ningxia Province during the period 1960-2015,the characteristics of spatial and temporal distribution of fog events over four main highways in Ningxia were analyzed.By using the analytic hierarchy process and fuzzy comprehensive evaluation method,average fog days,average duration,drainage density and road density,10 evaluation indexes were selected to construct the evaluation model of highway fog disaster in Ningxia,and then to proceed risk assessment and regionalization.The main results were as below: fog days over Ningxia highways mainly concentrated in September to November.The high-impact period of fog events influencing highway was 02: 00 to 08: 00.The annual average fog days were different among different highways.Annual average fog days gradually reduced from the middle to the north and south over Beijing-Tibet Expressway.More fog days occurred over the western Dingbian-Wuwei Expressway than the eastern parts;fewer fog days occurred over the northern Fuzhou-Yinchuan Expressway than the southern part;more fog days occurred over the northern Qingdao-Yinchuan Expressway than the eastern part.There were three high fog impact risk centers for Ningxia highways: Yinchuan section and Qingtongxia section of Beijing-Tibet Expressway,Zhongwei section of Dingbian-Wuwei Expressway,and Guyuan section of Fuzhou-Yinchuan Expressway.Relatively high risk area centers were located in Pingluo section of Beijing-Tibet Expressway,Zhongning section and Yanchi section of Dingbian-Wuwei Expressway,and Guyuan section of Fuzhou-Yinchuan Expressway.Other sections were lower risk area.