基于百度街景图像的兰州市安宁区行道树研究

Study on Street Trees in Anning District of Lanzhou City Based on Baidu Street View Images

摘要:

对城市绿视率和行道树结构特征进行综合研究，可为提升城市绿化效果和生态环境质量提供参考，为城市绿化规划提供科学依据。选取兰州市安宁区 6 个中心街区共 40 条街道，利用 ArcGIS 和 Python 软件获取百度街景图像，运用 ImageJ 或 Sketchup 获得行道树的结构特征数据，使用DeepLabv3+ 模型获得绿视率数据并进行定量分析。结果表明：在安宁区街道绿化中整体应用最 多、频度最高的是槐Styphnolobium japonicum；树高 5 m~10 m 的树木达到 75.5%，冠幅在4 m~8 m 的树木达到 58.3%，胸径大于 45 cm 的树木仅有 2.3%；低绿视率街道占研究区域的 75.3%、高绿视率街道仅占 7%。植物的树高、冠幅、胸径等生长指标的变化会影响叶片郁闭度，从而影响绿视率，且均与绿视率呈正相关关系，在一定程度上影响了居民的视觉体验和心理感受。 基于结果，建议对高绿视率的培黎街道进行定期修剪和维护，对中低绿视率的孔家崖街道和安宁堡街道等，以乔灌草搭配的方式，种植本土树种，提升绿视率。

Abstract:

Comprehensive research on the urban green visible index and the structural characteristics of street trees can provide a reference for improving the urban greening effect and ecological environment quality as well as provide a scientific basis for urban greening planning. A total of 40 streets in 6 central blocks of Anning District of Lanzhou were selected for this study. ArcGIS and Python software were used to obtain Baidu Street View images, ImageJ or Sketchup was used to obtain street tree structural feature data, and the DeepLabv3+ model was used to obtain green view rate data and conduct quantitative analysis. The results showed that the most frequently used street greening in the Anning district was Styphnolobium japonicum. Trees with a height of 5 m~10 m reached 75.5%, trees with a crown width of 4 m~8 m reached 58.3%, and trees with a diameter at breast height greater than 45 cm only 2.3%. Streets with low green vision accounted for 75.3% of the study area, while streets with high green vision accounted for only 7%. The changes in plant growth indicators such as the tree height, crown width and diameter at breast height will affect the leaf canopy and thus affect the green visible index, and all of them are positively correlated with the green visible index, which affects the visual experience and psychological feeling of residents to a certain extent. Based on the conclusion, it is suggested that the streets of Peili with high green vision should be trimmed and maintained regularly, and the streets of Kongjiaya and Anningbao with medium and low green vision should be planted with native tree species to improve the green vision.