基于绿视率的城市绿化评估——以武汉江汉区为例

A Study of Urban Greening Assessment Based on Visible Green Index:A Case Study of Jianghan District in Wuhan

目前我国仍以3大传统绿化指标评估城市绿化的二维情况,缺乏三维空间绿化效果评估。文章以武汉市江汉区为例,采用系统抽样法,将江汉区划分为472个250m×250m网格,基于腾讯地图的街景图像计算绿视率,从江汉区绿视率整体空间格局、不同用地类型绿视率差异性以及绿化覆盖率对绿视率的影响等方面评估该片区的三维绿化,结果显示:1)江汉区不同区域绿视率差异较大,平均值为16.26%;2)公园绿地、居住用地、商业用地的绿视率依次递减;3)绿视率随绿化覆盖率的增加而增加,但其增长趋势逐渐趋缓。

Three traditional greening indicators are used to assess the two-dimensional urban greening in China, which lacks in three-dimensional spatial greening assessment. With Jianghan District in Wuhan as the example, this paper adopts the method of systematic sampling to divide Jianghan District into 472 grids with the size of 250×250 m and evaluate the three-dimensional greening, based on the street view images of Tencent Map. The analysis is carried out as follows: the overall spatial pattern of visible green index, the difference of visible green index among different land use types, and the influence of green coverage on visible green index. The results show that: 1) there are significant differences in visible green index among different areas in Jianghan District, with an average value at 16.26%;2) the visible green index decreases from park green space, residential land, and commercial land;and 3) the visible green index increases with the increase in green coverage, but its growth trend gradually slows down.