基于摩拜骑行数据的上海市共享单车减排效益时空分析

移动互联网环境下的共享单车能够有效减少机动化出行，可在一定成程度上缓解当下交通污染、气候变化等问题，具有显著的减排效益.本研究基于上海市摩拜单车的骑行数据，结合精细化的交通方式排放因子及共享单车替代率调查数据，计算共享单车与其替代交通方式相比所减少的温室气体排放和污染物排放，并分析共享单车减排效益的时空分布特征.结果表明：2016年上海市共享单车的CO₂、CO、HC、NO_x、PM_2.5和PM₁₀减排量分别为6322、74、8.57、6.33、0.32、0.48 t；在时间上具有典型的峰谷现象，其中，早晚高峰贡献了约45%的减排量；在空间上主要分布于中心城区，其中，南京东路街道单位面积减排量最高.因此，上海市共享单车的减排效益主要产生于早晚通勤交通与人口集聚的地区.为了提高共享单车的减排效益，政府和运营者需要在未来继续扩大共享单车的覆盖范围，增加在郊区的投放数量，鼓励更多外围居民使用共享单车.

Temporal and spatial analysis of the emission reduction benefits of bike-sharing in Shanghai based on Mobike riding data

Bike-sharing in the environment of mobile Internet can effectively reduce motorized travel, which can alleviate the current problems of climate change and traffic pollution to a certain extent. Thus, bike-sharing can bring significant benefits of emission reductions. Based on the riding data of Mobike in Shanghai, this study combines refined survey data on emission factors and substitution rates of alternative transportation modes of bike-sharing to calculate the greenhouse gas emissions and pollutant emissions reduced by bike-sharing compared with their alternative transportation modes. Furthermore, it analyzes the temporal and spatial distributions of the emission reduction benefits of bike-sharing. The results show that the emission reductions of CO₂, CO, HC, NO_x, PM_2.5, and PM₁₀ from bike-sharing in Shanghai in 2016 were 6322, 74, 8.57, 6.33, 0.32, and 0.48 t, respectively. In terms of temporal distribution, there are typical peaks and valleys, with the morning and evening peaks contributing about 45% of the emission reductions. In terms of spatial distribution, emission reductions are concentrated in the central city, with the highest emission reductions per unit area in Nanjing East Road street. Therefore, the emission reduction benefits of bike-sharing in Shanghai are mainly generated in areas with a high concentration of population during peak hours for commuting. In order to boost the emission reduction benefits of bike-sharing, the government and operators should continue to expand the coverage of bike-sharing, increase the number of shared bikes in suburban areas, and encourage more peripheral residents to use bike-sharing in the future.