Analysis of traffic noise spatial distribution characteristics and influencing factors in high-density cities

Urban spatial structure factors can have considerable effects on traffic noise distribution. This study aimed to describe the spatial distribution characteristics of traffic noise and influencing factors in high-density cities. Fifteen indexes were selected from the three aspects of building layout, road organization and land use to analyse the influence of urban spatial structure factors on the noise spatial distribution. This paper selected the central area of Tianjin as the study area. The noise level was generated by the noise simulation software CadnaA, and the numerical statistics were determined by ArcGIS. The correlation between various urban indexes and the spatial distribution of traffic noise were determined with correlation analysis, and multiscale geographically weighted regression (MGWR) analysis was used to determine the degree and scope of influence of various urban indexes on the spatial distribution of traffic noise. The results indicate that there are significant differences in the spatial agglomeration forms of high, medium, and low noise areas among research units, and the spatial agglomeration of low noise areas in each unit is stronger. The building layout indexes, except for the average building height (ABH), are significantly negatively correlated with the noise levels in low noise areas (L70-L90). The road length index (RLI), road area density (RAD), road landscape shape index (RLSI), trunk road length index (TRLI), proportion of traffic land (PT), and degree of land mixing (DLM) are significantly positively correlated with the noise levels of all areas within the unit (L10-L90). Among the three aspects of building layout, road organization, and land use, the architectural landscape shape index (ALSI), RAD, and DLM have the greatest influence on the average spatial sound pressure level (Lavg), with mean regression coefficients of -0.254, 0.520, and 0.174, respectively. The ground space index (GSI), ALSI, proportion of residential land (PR) and PT are the global factors influencing Lavg.