Traffic Noise Pollution Assessment In Southern Suburbs Of Xi'an

According to the national announcement data, in recent years about 49% of the sound environment in cities were the moderate pollution, 30% were the light pollution, and 10% were good. 17% of the traffic noises were the moderate pollution, 49% were the light pollution, and 29% were good. Traffic noise pollution is disturbing the daily life of the urban dwellers badly. So evaluating the traffic noise pollution has important significance in theory and practice.In recent years, the economy developed rapidly and the city expanded continuously in Xi'an, however the construction of urban traffic facilities is left far behind, which has made the traffic noise problem besides main roads serious increasingly. Through making a detailed investigation, we found that research on the present road traffic noise in Xi'an is few. This paper selects main prosperous road which is ChangAn road,Second Ring road,Youyi road and Huancheng road in southern suburbs of Xi'an, and carries on-the-spot monitoring of traffic noise. According to the monitor results and investigation materials, this paper has studied comprehensively the noise property, propagation characteristics, causes, damages to the people and current main control measures, evaluated the grade of noise pollution and presented some effective measures. This research could provide scientific basis for controlling traffic noise and governmental decision-making.Based on research the conclusions were reached as bellow:(1) According to the monitoring data and analysis to temporal variations of traffic noise in southern suburbs of Xi'an, it was concluded that in southern suburbs of Xi'an the traffic noises in 8 : 00-9 : 00 am and 18 : 00 -19 : 00 pm were higher and the values were respectively 72.04-72.07 dB and 71.52-71.57 dB, which was related to big vehicle flux and strong human activities.(2) According to the monitoring data and analyses to the integral characteristics of traffic noises in southern suburbs of Xi'an and to the influence of different regions' traffic noises on surroundings, it was concluded that the traffic noise pollution in southern suburbs of Xi'an was serious. The average of Leq was 71.39dB on Huancheng road, 71.30dB on Youyi road, 71.40dB on second ring road, and 71.37dB on ChangAn road. It was 1-2 dB exceeding the national standard and 4 main roads were all slight pollution. (3) Traffic noise in Southern Suburbs of Xi'an decreased with the distance increase in horizontal direction. 70-100m to the edge of roadsides can achieve regional environmental noise standards for living, culture and education, 30-60 m to the edge of roadsides can achieve the residential, commercial, mixed environmental noise standards, 20m can achieve the industrial areas environmental noise standards, 10m can achieve the road traffic noise standards, and between 0-5 m the noise value were over standard. Traffic noise in Southern Suburbs of Xi'an increased with the increasing of the storey firstly, and then decreased. Traffic noise reached the maximum of 67.2dB at the range of 2-7 storey (5-19 m), and then decreased regularly with the increasing of the storey.(4) Based on analyses, it was known that the main factors traffic noise in southern suburbs of Xi'an was vehicle flux,vehicle driving conditions,vehicle performance,urban traffic management, road construction and so on. In addition, the indirect factors were the faint consciousness to traffic rules and serious phenomena of vehicle whistle. Developing studying and propagating traffic rulesmaybe can put an end to phenomena of vehicle whistle and decrease traffic noise.