Evaluating Neighborhood Green-Space Quality Using a Building Blue-Green Index (BBGI) in Nanjing, China

Abstract

High-quality urban green space (UGS) is an integral part of a livable city. The scientific evaluation of UGS has great value for improving the quality and efficiency of green spaces. In this study, we integrated the water and walking networks into the existing green index model and proposed a new green index: The building blue-green index (BBGI). Using this method, we analyzed the quality of green spaces within 300 m of 2138 buildings located in 13 communities in the Mochou Lake subdistrict in Nanjing, China. The results revealed that the green-space quality of high-rise, low-density buildings was greater than that of low-rise, high-density buildings. In addition, buildings close to water had higher green-space quality, while impervious surfaces reduced green-space quality. Furthermore, the connectivity and orientation of the road network indicated that even if a community was close to large parks and water bodies, there would still be lower green-space quality. This study’s findings highlight the usefulness of evaluation methods for green-space quality that combine blue and green spaces. We also propose feasible measures for improving neighborhood green-space planning and land management.