基于街景图像的北京市中轴线道路系统绿视率特征分析

Analysis of Green View Index in Beijing Central Axis Road System Based on Street View Image

文章以北京市传统中轴线及向北延伸至北四环的区域为研究范围,选用2017年7月中旬沿线不同等级街道的街景图像,运用Adobe Photoshop CC 2018、ImageJ和SPSS 20.对街道系统绿视率进行统计计算和辅助分析。研究结果发现:北京市中轴线绿视率整体呈现一般的绿化水平,各街道(及广场)绿化评价占比情况为绿化水平一般>较好>差>高>较差;中轴线绿化重视程度北部大于南部;街道等级和街道剖面结构不是影响绿视率的主要因素,绿化带宽度、绿色景观连续性及植被养护状况等植被因素的综合考虑是提高绿视率的有效方案;中轴线的绿化建设应当提高对天安门广场、商业步行街和南部二级道路的重视程度,同时加强植被的养护管理。

With the focus on the traditional central axis extending to the North Fourth Ring Road in Beijing,this paper chooses the street visual images of different gradients of street in mid-July 2017 to statistically calculate and analyze the green visual rate of street system.The study finds that the green view index at Beijing's central axis reflects the general level of greening.The proportion of greening evaluation of streets(and squares)greening is ordered by general>good>poor>excellent>sub-standard.More attention has been paid to the greening in the north of the central axis than that in the south.Street grades and street profile structure are not the critical influencing factors to green view index,while the integrated consideration of the vegetation elements such as green belt width,green landscape connectivity and vegetation maintenance is the effective solution to green view index improvement.The greening of the central axis should pay more attention to Tian'anmen Square,commercial pedestrian street and the secondary roads in the Southern Part,and the maintenance and management to vegetation should be strengthened.