Relationship between road vehicle traffic and noise pollution of Khojir National Park in the viewpoint of feasibility of fencing and soundproofing

Abstract

Aims: The main aim of this study was to investigate the relationship between the amount of noise pollution and traffic rates in Khojir National park and regarding that finding a suitable distance for installing fencing according to the standard level of noise pollution. Materials and Methods: Eight stations located exactly above channels have been selected. In each station, three different substations including near the road, 25, and 50 m from the road were chosen. For determining the essentiality of soundproof installation, noise levels were measured at the opening and in the middle of the channel. Traffic rates have been measured daily from 6 AM to 6 PM for two continuous weeks and noise levels were then determined in three different days according to the traffic peak. Results: Results obtained showed a significant relationship between traffic rates and noise levels in near-road stations (R 2 linear = 0.341). The relationship between interval and noise level was also significant (R 2 quadratic = 0.701, P < 0.05). Furthermore, a distance with 55 dB (A) (i.e., 50 m in this study) was achieved as a proper site for fencing. Conclusion: Although the amount of noise levels in the middle of channels were less than the standard level, this amount in some channel throats were higher and need to be considered for soundproof installation as well. In addition to finding an area for fencing, using solution(s) for reducing either noise pollution or its impact at this area should be taken into consideration.