基于精细化年均行驶里程建立机动车排放清单

基于环保检测数据,提出“里程-车龄”曲线用以获取满足“车辆类型-燃料种类-排放标准”三级分类的精细化年均行驶里程.使用《道路机动车大气污染物排放清单编制技术指南（试行）》推荐值、车辆类型均值、“里程-车龄”曲线3种方式获取年均行驶里程并分别建立排放清单,发现年均行驶里程的本地化与精细化可以极大降低行驶里程不确定性对排放清单准确性的影响.采用精细化年均行驶里程,计算得到青岛市2017年机动车CO、VOCs、NO_x、PM₁₀、NH₃和SO₂的排放量分别为7.07,1.14,2.84,0.10,0.08和0.08万t.分析排放构成可知,老旧车淘汰在当前仍可作为青岛市机动车排放治理的有效举措.结合路网信息与交通数据,得到0.01°×0.01°高时空分辨率网格化排放清单.结果表明,青岛市机动车排放分布在不同时段变化明显.以NO_x为例,排放的早晚高峰分别出现在8：00与17：00,占到了全天总排放的8.17%和7.53%.同时,排放分布存在着空间异质性,排放从城市中心至边缘呈逐渐降低趋势,沿高速路呈明显带状分布.

Developing vehicle emission inventory based on refined annual average vehicle kilometers travelled

Based on the data from the vehicle inspection station, the "VKT-age" curve was introduced to obtain refined VKTs that could be classified according to vehicle type, fuel type, and vehicular emission standards. Three kinds of VKT were applied to develop emission inventories to evaluate how results were affected by the localization and refinement of VKT, including the recommended VKT from the official guide, the VKT only classified by vehicle type, and the VKT simulated by "VKT-age" curve. It was found that the localization and refinement of VKT could significantly reduce the uncertainties caused by VKT and improve the accuracy of emission inventories. The refined VKTs were applied to estimate the vehicle emissions in Qingdao in 2017. The emissions of CO, VOCs, NOx, PM10, NH3, and SO2 are 70.7, 11.4, 28.4, 1.0, 0.8, and 0.8 Gg, respectively. The analysis of the emission composition showed that scrapping older vehicles was still an effective policy for controlling vehicle emissions. By combining with the road network and traffic data, a gridded vehicle emission inventory with a high temporal-spatial resolution of 0.01°×0.01° was developed. The results showed that the emissions distribution varied significantly at different times. Taking NOx as an example, the morning and evening peaks of emissions occurred at 8:00 and 17:00, with the contribution of 8.17% and 7.53% to the daily emissions. The spatial heterogeneity was observed in emissions that decreased gradually from downtown to suburb and showed a line distribution along the freeway.