[Methods for Determining and Applications of High-Resolution Vehicle Emission Inventory at County Scale].

This study proposes a method for high-resolution vehicle emission inventories at county scale based on field investigations and Google Earth satellite images, using the Tongzhou district of Beijing as an example for data analysis. VKT and the corresponding emissions of each pollutant were calculated using the number of registered vehicles and the real-time traffic volumes, respectively. The results showed that the mileage calculated based on the method using registered vehicles is about 37% less than that based on real-time traffic volumes, with the latter method providing data closer to the actual situation. The mileage for small passenger cars, large passenger vehicles, and medium-duty trucks were underestimated, and that for light trucks, heavy trucks, low-speed trucks were overestimated based on the registered vehicle method. Emissions from small passenger cars were also underestimated by about 51%, using the registered vehicle method. For emissions of large passenger vehicles, light trucks, and medium-duty trucks, there was less difference between the two methods. Based on the registered vehicle method, emissions of heavy trucks, low-speed trucks, and motorcycles were overestimated by about 41%, 30%, and 30%, respectively.