相似离度在北京市道面结冰预报中的初步应用

A Preliminary Application of Analog Deviation to Road Icing Prediction in Beijing Region

结冰是影响交通运输安全的不利气象条件中最恶劣的条件之一。尝试将相似性原理中的相似离度方法应用于北京市道面结冰的预报中。选取北京市主要路段的15个ROSA道面气象站时间分辨率为5分钟一次的高时空分辨率观测资料,从2004—2008年的历史资料中挑选出道面结冰的样本,选用气温、路面温度和相对湿度3个因子,采用相似离度方法,通过计算2009年11月至2010年3月(以下简称2009年冬季)各路段监测点上每间隔5分钟的各气象要素与本站历史上出现结冰的样本之间的相似离度,遴选出相似离度最小即最相似的状况,制定出相似离度临界阈值,进而对2009年冬季道面结冰状况(即有无结冰)进行预报,并利用15个ROSA道面气象站2009年冬季出现的实际道面状况对预报效果进行了检验。结果表明,对于15个ROSA道面气象站,总体而言,预报正确率为67.6%。有9个站的预报正确率在61%以上,只有3个站的预报正确率在50%以下。由此可见,相似离度方法在北京市道面结冰的预报初步试验当中取得了比较满意的结果,可推荐在北京市道路交通气象服务系统中进行业务试用。

Road icing is one of the worst phenomena in adverse meteorological conditions.In this paper,a new method of Analog Deviation is introduced to road icing prediction in Beijing region.Based on the fine resolution observation data which was observed by the 15 auto monitoring stations for road weather information,road icing samples are selected,then the factors of air temperature,road surface temperature and relative humidity are screened from all the observation elements to apply to Analog Deviation method.The specific computation procedures are:(1)Analog Deviation between the icing samples from November of 2009 to March of 2010(hereinafter called 2009 winter)and historical icing samples is computed,(2)select the minimum of Analog Deviation,(3)critical value is determined,(4)predict road icing or not,(5)effective test of prediction.The results show that the rate of true prediction is 67.6 percent in all.Therefore,the method of Analog Deviation proves to be a feasible one to predict road icing in Beijing region,and could be recommended to use in the service system for ease of road icing.