高速交通网络及道路运输量快速发展,使高速径流污染问题日益突出。在对天津城区以外的高速公路进行持续监测分析的基础上,结合交通流参数调查与污染检测结果,探讨了污染指标和交通流特性的相互关系。结果表明:(1)高速公路雨水径流初期污染较严重,COD、BOD5、TN、TP、氨氮最高值分别达到了《地表水环境质量标准》(GB 3838—2002)中Ⅴ类限值的15.6、5.0、5.3、2.1、6.5倍。SS是污染的主要因素。(2)污染指标多数与时间成负指数或对数关系,即污染指标先快速减少到一定程度后变化减缓甚至趋于稳定。(3)交通量及密度是造成高速公路雨水径流污染的主要原因,车速存在着一个污染较少的最优段,但对高速公路雨水径流污染的总体影响效果较小。
The problem of high speed runoff pollution becomes more and more serious as the high speed trafficnetwork and road transport develop rapidly. On the basis of continuous monitor and analysis of the expressway in Tianjin City,and combining with the traffic flow parameters investigation and the pollution detection results,the rela-tionship between the pollution index and traffic flow characteristics was discussed. The results showed that: (1) the pollution was serious in the early stage of the storm water runoff,and the highest values of COD,BOD5 ,TN,TP and ammonia nitrogen reached 15.6,5.0,5.3,2.1 and 6.5 times of the corresponding values of the water body standard V of “Environment quality standards for surface water ”(GB 3838-2002) . SS was the main factor of pollution. (2) The majority of pollution index and time were in a negative exponential or logarithmic relationship,i.e. the pollution index first quickly reduced to a certain degree,after that the decreasing tendency became slow and even stable. (3) The traf-fic volume and density were the main reasons for the pollution of storm water runoff, and vehicle speed had an optimal section with less pollution, while the overall effect was small.