街道绿化:一个新的可步行性评价指标

Street Greenery: A New Indicator for Evaluating Walkability

街道绿化对居民尤其是行人的生活质量至关重要,是评估街道可步行性的重要指标之一。传统受限于数据获取的困难,对街道绿化的研究多局限于较小的地域,而目前运用新兴的街景图片进行评价的方法也多基于人工判断。通过构建一种自动的方法,实现了大规模、精细化尺度的街道绿化的量化评价,并以成都一、二圈层的街道为案例进行实践。研究发现:成都街道以不绿和一般绿街道为主;二圈层的街道绿化好于一圈层的街道;东部、北部个别街道绿化较好,南部、西部整体绿化相对较好;绿化相对较好的街道主要与大学、公园景点、河流两侧、居住区有关;街道绿化与道路等级、街道周边地块性质、区位等相关。对步行系统规划、街道品质改善提升等工作具有一定的指导意义。

We propose an automatic method using emerging online street view service for quantitatively evaluating greenery at street level in a large area,and then apply it for analyzing street greenery in the first and second circle of Chengdu,one of large cities in the west of China.We calculate thegreenery of each street by Green Looking Ratio,one index suitable for evaluating visible greenery.We find that(1)streets closer to city centertend to be less green;(2)greener streets of Chengdu are more frequently related with the riverside,parks,spots and communities in the fringe ofcore area;(3)different road grade and different land use around show different greenery of streets.The findings may help draft more appropriatepolicies in planning and engineering practices for street greenery.