Spatial attenuation characteristics and influencing factors of traffic noise in high-density cities: A case study of Tianjin, China

Amid increasing concerns regarding traffic noise pollution, existing research has demonstrated correlations between spatial noise distribution and urban parameters including land use patterns, traffic flow dynamics, and building layouts. Nevertheless, critical gaps persist in establishing actionable frameworks to identify and mitigate high-noise pollution zones during urban planning processes, particularly in high-density cities. This study systematically identifies the spatial attenuation characteristics and determinants of traffic noise in Tianjin through noise map, clustering analysis, correlation analysis, structural equation modelling. The findings revealed that (1) the units with traffic noise spatial attenuation can be classified into four types: attenuation primarily in high noise areas, attenuation primarily in medium noise areas, attenuation primarily in low noise areas, and low total attenuation. (2) The attenuation values of noise in the high and medium noise areas are positively correlated with the ground space index, building boundary density, architectural landscape shape index, and proportion of residential land, and are negatively correlated with the proportion of green space. (3) Through structural equation modelling analysis, this study revealed that the building indicators have a greater effect on the attenuation values of noise in the medium noise areas; the road indicators have a greater effect on the attenuation values of noise in the high noise areas; and the land use indicators have greater effects on high, medium and low noise areas. This study provides evidence-based urban planning strategies for mitigating traffic noise exposure in high-density cities.