都市农业对食物运输的碳减排潜力评估——以南京主城区为例

Carbon emission reduction potential assessment in food transportation by urban agriculture:A case study of main urban area of Nanjing,China

都市农业作为新型城市绿色基础设施和连贯式生产性城市景观,能够大幅提升城市食物系统的韧性并减少食物运输过程中的碳排放。然而,目前国内评估都市农业发展潜力及其碳减排效益的研究尚不多见。本研究以南京主城区为例,基于卫星影像和Lidar点云等数据,采用语义分割、空间分析等方法,识别了研究区适合发展都市农业的地面潜力空间和屋顶潜力空间,并估算了其潜在的蔬菜产量和在食物运输方面的CO_(2)减排效益。结果表明:研究区分别有2904.39 hm^(2)的地面空间和2976.96 hm^(2)的屋顶空间可作为发展都市农业的潜力空间;在潜力空间利用率为80%的情景下,每年可生产蔬菜约22.50万t,相当于研究区年蔬菜消费量的43.6%,同时,可减少从外地输入食物过程中所产生的6.37万t CO_(2)排放。

As an emerging urban green infrastructure and continuous productive urban landscape,urban agriculture can increase the resilience of urban food systems and reduce carbon emission in food transportation.However,there are few studies in China on the potential of urban agriculture and its role in carbon emission reduction.With semantic segmentation and spatial analysis method to identify urban agricultural potential spaces on the ground and rooftops based on satellite images and Lidar point cloud data in the main urban area of Nanjing,we estimated their potential in vegetable production and the CO_(2) emission reduction effect in food transportation.The results showed that there were 2904.39 hm^(2)of ground and 2976.96 hm^(2)of rooftops in the study area with the potential to be used for urban agriculture.Under a scenario with 80%potential space utilization,it could produce approximately 225000 t of vegetables per year,which equated to 43.6%of annual vegetable consumption in the study area.Meanwhile,it would reduce CO_(2) emission in long distance food transportation by 63700 t per year.