北京机动车限行对空气质量的影响分析

Analysis of Beijing cars with license plates allowed on the streets on air quality impact

为减少机动车尾气排放,确保奥运期间的空气质量达到标准,北京市政府从奥运前就开始对在京机动车采取单双号限行措施。奥运结束后,为保证空气质量及缓解交通出行的路面拥堵状况,仍然进行按车牌尾号"每周停驶1天"的机动车限行政策。分析北京市近7年的空气质量状况,并着重分析奥运前后及限行期间的空气质量状况,将这7年的空气质量状况与限行同期进行对比,据此分析限行措施带来的NO_2和可吸入颗粒物的减排效果。在限行政策实施期间,北京城市大气中的NO_2和可吸入颗粒物的浓度均有所降低,其中以NO_2的降低效果最为明显,说明北京市机动车限行政策的实行对空气质量的好转有一定贡献。

With the rapid growth of national economy in recent 10 years, the numbers of motor vehicles accordingly have been increasing significantly. Meanwhile, the air pollution caused by exhaust gas of motor vehicles is deteriorating as well. In order to reduce exhaust gas emissions from the motor vehicles, Beijing has begun to enhance the traffic control complying with the international practice ever since the pre-Olympics days. From July 20 to September 20, motor vehicles with license plates ending with even numbers were allowed on road for the even-numbered dates, and the same policy went to those with license plates ending with odd numbers on odd-numbered dates. After the Olympic Games, with the purpose of ensuring air quality and relieving traffic congestion, the policy was continued with some adjustments. The traffic restriction from Monday to Friday is made depend on the last two numbers of the vehicle＇ s license plate. The status of air quality in Beijing for nearly seven years ranged from 2003 to 2009 was reviewed. The study has emphasized on the state of air quality before and after Olympic Games as well as the air quality during the period of restriction implementation. At the same time, we compared the data for the time of restriction policy implementation with the same period in previous years. From there, the further work has analyzed the effect of pollutant emission reduction brought by the traffic restriction. The data showed that the concentration of nitrogen dioxide and particulate matter decreased in the atmosphere of Beijing area and has been maintained at a relatively low level continuously to date. The reduction of nitrogen dioxide in atmosphere is more obvious. It can be concluded that the implementation of the traffic restriction policy has greatly contribute to the air quality improvement in Beijing.