Spatial relationship between green view index and normalized differential vegetation index within the Sixth Ring Road of Beijing

Urban green space (UGS) has been recognized as a critical urban landscape design element. The green view index (GVI), as an indicator to quantify the perception of green landscape from the pedestrians’ perspective, has been widely used to evaluate the quality and aesthetic ecosystem services of urban green spaces. Therefore, to quantify the quality and regional differences of urban road greening in the horizontal or vertical dimensions within the Beijing Sixth Ring Road, this study analyzed the spatial pattern of road GVI at different levels, including at sample points, roads, and counties, and evaluated the differences in road GVI in different urban functional zones in 2014. Based on the geographically weighted regression model, this study further analyzed the spatial heterogeneity between road GVI and the normalized difference vegetation index (NDVI). The results showed that the average road GVI at sample point level, road level, and county level within the study area were 17.2 %, 15.3 %, and 15.7 %, respectively, which were overall relatively low. The road GVI between adjacent ring roads from inside to outside showed an obvious regional difference. The ranking of average road GVI in different functional zones was as follows: tourism zone (15.68 %) > residential zone (15.12 %) > service zone (14.70 %) > cultural zone (14.22 %) > commercial zone (12.35 %). Road GVI showed a significant positive correlation with NDVI but spatial heterogeneity existed. Research on the spatial characteristics of urban road greening is helpful for urban planners and managers to plan and design urban road greening more accurately and effectively.