ارزيابي تأثير پوشش درختي حاشيه و شيب طولي جاده جنگلي بر ميزان نفوذ صوت موتور كاميون هاي حامل چوب

Investigating the effect of marginal trees cover and longitudinal slope of forest road on noise entrance of Truck engine in Kheyrood forest

ﺳﺎﺑﻘﻪ و ﻫﺪف: ﺟﺎده ﻫﺎ و دﯾﮕﺮ زﯾﺮﺳﺎﺧﺖﻫﺎي ﺧﻄﯽ از ﻣﻬﻢ ﺗﺮﯾﻦ ﻧﻤﻮﻧﻪ ﻫﺎي ﻓﻌﺎﻟﯿﺖ ﻫﺎي ﺑﺸﺮي در اﮐﻮﺳﯿﺴﺘﻢﻫﺎي ﻃﺒﯿﻌﯽ ﺑﻪﺷﻤﺎر ﻣﯽ روﻧﺪ، ﮐﻪ ﻣﯽﺗﻮاﻧﻨﺪ ﺗﺄﺛﯿﺮات ﻣﺨﺮﺑﯽ ﺑﺮ زﯾﺴﺘﮕﺎه ﻫﺎي ﻃﺒﯿﻌﯽ داﺷﺘﻪ ﺑﺎﺷﻨﺪ. از ﺑﺎرزﺗﺮﯾﻦ ﺗﺄﺛﯿﺮات ﻧﺎﻣﻄﻠﻮب، ﻣﯽﺗﻮان ﺑﻪ آﻟﻮدﮔﯽ ﻫﺎي زﯾﺴﺖﻣﺤﯿﻄﯽ اﺷﺎره داﺷﺖ ﮐﻪ در ﺳﻪ دﻫﻪ اﺧﯿﺮ ﺑﯿﺶ از ﮔﺬﺷﺘﻪ ﻣﻮرد ﺗﻮﺟﻪ واﻗﻊ ﺷﺪه اﺳﺖ. ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ ﻣﯿﺰان اﻧﺘﺸﺎر ﺻﻮت ﺣﺎﺻﻞ از ﻣﻮﺗﻮر ﺧﻮدرو ﺳﻨﮕﯿﻦ ﺑﺎ ﺣﺠﻢ ﻣﻮﺗﻮر ﺑﺎﻻ در دو ﻃﺒﻘﻪ ﺷﯿﺐ ﻃﻮﻟﯽ ﺟﺎده ﺟﻨﮕﻠﯽ و ﺷﻨﺎﺧﺖ ﻧﻮع راﺑﻄﻪ ﮐﺎﻫﺸﯽ ﻣﯿﺰان ﺷﺪت ﺻﻮت ﺑﺎ اﻓﺰاﯾﺶ ﻓﺎﺻﻠﻪ از ﺟﺎده ﻣﯽﺑﺎﺷﺪ. ﻣﻮاد و روش ﻫﺎ: ﺑﻪ ﻣﻨﻈﻮر اﻧﺪازه ﮔﯿﺮي ﻣﯿﺰان ﺷﺪت ﺻﻮت ﺗﻌﺪاد ﻫﺸﺖ اﯾﺴﺘﮕﺎه در ﻃﻮل 20 ﮐﯿﻠﻮﻣﺘﺮ ﺟﺎده ﺟﻨﮕﻠﯽ اﺻﻠﯽ ﯾﮑﻄﺮﻓﻪ ﺷﻦ رﯾﺰي ﺷﺪه ﺟﻨﮕﻞ آﻣﻮزﺷﯽ ﭘﮋوﻫﺸﯽ داﻧﺸﮕﺎه ﺗﻬﺮان )ﺧﯿﺮودﮐﻨﺎر ﻧﻮﺷﻬﺮ( ﺑﺎ ﻃﺒﻘﻪ ﻫﺎي ﺷﯿﺐ ﻃﻮﻟﯽ ﭘﺎﯾﯿﻦ )5-2 درﺻﺪ( و ﺑﺎﻻ )8- 11 درﺻﺪ( و ﻓﻮاﺻﻞ ﺻﻔﺮ )ﺣﺎﺷﯿﻪ ﺟﺎده(، 25 ﻣﺘﺮ، 50 ﻣﺘﺮ، 75 ﻣﺘﺮ، 100 ﻣﺘﺮ ﺑﻪ ﺳﻤﺖ داﺧﻞ ﺗﻮده و در ﻗﺴﻤﺖ ﭘﺎﯾﯿﻦ دﺳﺖ ﺟﺎده و ﻣﺤﻮرﺟﺎده )ﻧﺰدﯾﮏ ﺗﺮﯾﻦ ﺣﺎﻟﺖ ﺑﻪ ﻣﻮﺗﻮر ﺧﻮدرو( ﺑﻪ ﻋﻨﻮان ﻧﻘﺎط ﺻﻮت ﺳﻨﺠﯽ اﻧﺘﺨﺎب ﺷﺪ. ﻣﯿﺎﻧﮕﯿﻦ ﺳﻄﺢ ﺻﻮت ﻣﻨﺘﺸﺮ ﺷﺪه از ﺧﻮدرو ﮐﺎﻣﯿﻮن ﺑﻨﺰ 2624 اﻧﺪازه ﮔﯿﺮي ﺷﺪ. اﯾﻦ ﻋﻤﻞ ﺗﻮﺳﻂ دﺳﺘﮕﺎه ﺻﻮت ﺳﻨﺞ دﯾﺠﯿﺘﺎل SL-4023SD ﺑﺎ دﻗﺖ 1/5 دﺳﯽ ﺑﻞ و ﻗﺪرت ﺗﻔﮑﯿﮏ 0/1 دﺳﯽ ﺑﻞ اﻧﺠﺎم ﮔﺮﻓﺖ. ﻓﺎﮐﺘﻮر ﻣﯿﺎﻧﮕﯿﻦ ﺳﻄﺢ ﺻﻮت ﺑﺮاي وﺳﯿﻠﻪ ﻧﻘﻠﯿﻪ ﺑﺎ ﺣﺠﻢ ﻣﻮﺗﻮر ﺛﺎﺑﺖ در دو ﺳﻄﺢ ﺷﯿﺐ ﻃﻮﻟﯽ و ﭘﻨﺞ ﺳﻄﺢ ﻓﺎﺻﻠﻪ از ﺟﺎده اﻧﺪازهﮔﯿﺮي ﺷﺪ و ﺳﭙﺲ ﺗﺠﺰﯾﻪ وارﯾﺎﻧﺲ ﺑﻪوﺳﯿﻠﻪ ﻣﺪل ﺧﻄﯽ ﺗﻌﻤﯿﻢﯾﺎﻓﺘﻪ در ﻧﺮم اﻓﺰار SPSS اﻧﺠﺎم ﮔﺮﻓﺖ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ در اﯾﺴﺘﮕﺎه ﻫﺎي ﺑﺎ ﺷﯿﺐ ﻃﻮﻟﯽ ﻃﺒﻘﻪ ﭘﺎﯾﯿﻦ و اﯾﺴﺘﮕﺎه ﻫﺎي ﺑﺎ ﺷﯿﺐ ﻃﻮﻟﯽ ﻃﺒﻘﻪ ﺑﺎﻻ ﺑﻪ ﺗﺮﺗﯿﺐ 58/7 درﺻﺪ و 56/6 درﺻﺪ ﮐﺎﻫﺶ ﺷﺪت ﺻﻮت ﻧﺴﺒﺖ ﺑﻪ ﺣﺎﺷﯿﻪ ﺟﺎده ﻗﺎﺑﻞ ﻣﺸﺎﻫﺪه اﺳﺖ. در ﺗﻤﺎﻣﯽ اﯾﺴﺘﮕﺎه ﻫﺎ ﺑﺎ ﻓﺎﺻﻠﻪ ﮔﺮﻓﺘﻦ از ﻣﻨﺒﻊ ﺻﻮت ﺷﺪت ﺻﻮت ﮐﺎﻫﺶ ﻣﯽ ﯾﺎﺑﺪ اﻣﺎ ﺑﯿﺶ ﺗﺮﯾﻦ درﺻﺪ ﮐﺎﻫﺶ ﻣﯿﺰان ﺷﺪت ﺻﻮت در ﻓﻮاﺻﻞ 25-0 ﻣﺘﺮ از ﺣﺎﺷﯿﻪ ﺟﺎده ﺛﺒﺖ ﺷﺪه اﺳﺖ. ﺑﻪﻃﻮر ﮐﻠﯽ ﻧﻮع راﺑﻄﻪ ﮐﺎﻫﺸﯽ ﺷﺪت ﺻﻮت ﺑﺎ اﻓﺰاﯾﺶ ﻓﺎﺻﻠﻪ در اﯾﺴﺘﮕﺎه ﻫﺎي ﺷﯿﺐ ﻃﻮﻟﯽ ﻃﺒﻘﻪ ﭘﺎﯾﯿﻦ و ﺑﺎﻻ از ﻧﻮع ﻟﮕﺎرﯾﺘﻤﯽ ﻣﯽ ﺑﺎﺷﺪ. ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻧﺘﺎﯾﺞ ﻣﯽ ﺗﻮان درﯾﺎﻓﺖ ﮐﻪ ﺷﯿﺐ ﻃﻮﻟﯽ ﺟﺎده ﺗﺄﺛﯿﺮ زﯾﺎدي در ﻣﯿﺰان ﺷﺪت ﺻﻮت ﻣﻨﺘﺸﺮ ﺷﺪه از ﺟﺎده ﻧﺪارد. در اﯾﻦ ﭘﮋوﻫﺶ ﺗﻤﺎﻣﯽ ﻣﺘﻐﯿﺮﻫﺎ ﭼﻪ ﺑﻪﺻﻮرت ﻣﺴﺘﻘﻞ و ﭼﻪ ﺑﻪﺻﻮت ﻣﺘﻘﺎﺑﻞ ﺑﺮ ﻣﯿﺰان ﻧﻔﻮذ ﺻﻮت اﺛﺮ ﻣﻌﻨﯽ دار دارﻧﺪ. ﺑﺎ ﻓﺎﺻﻠﻪ ﮔﺮﻓﺘﻦ از ﻣﻨﺒﻊ ﺻﻮت ﺷﺪت ﺻﻮت ﮐﺎﻫﺶ ﻣﯽ ﯾﺎﺑﺪ. دﻗﺖ در ﻃﺮاﺣﯽ ﻣﺸﺨﺼﺎت ﻓﻨﯽ ﺟﺎده از ﺟﻤﻠﻪ ﺷﯿﺐ ﻃﻮﻟﯽ، ﺗﻌﻤﯿﺮ و ﻧﮕﻬﺪاري ﺳﻄﺢ روﺳﺎزي ﺟﺎده، ﺣﻀﻮر ﭘﻮﺷﺶ ﮔﯿﺎﻫﯽ در ﺣﺎﺷﯿﻪ ﺟﺎده و ﺟﻠﻮﮔﯿﺮي از ﺗﺨﺮﯾﺐ آن، ﺣﻔﻆ و اﺣﯿﺎي ﺗﺮاﮐﻢ درﺧﺘﺎن ﻣﻮﺟﻮد در ﺗﻮده ﮐﻨﺎر ﺟﺎده ﻣﯽ ﺗﻮاﻧﺪ ﺗﺎ ﺣﺪودي ﻣﯿﺰان ﺷﺪت ﺻﻮت ﻣﻨﺘﺸﺮ ﺷﺪه از ﺟﺎده را ﮐﺎﻫﺶ دﻫﺪ

Background and purpose: Roads and other linear structures are the most important examples of human activities, and it can be mentioned that they have the most critical environmental effects on the natural habitats and ecosystems of the world. One of the most obvious of these adverse effects is environmental pollution, which has received more attention in the last three decades.The purpose of this study was to investigate the sound level of a heavy vehicle engine with a high engine volume in two different longitudinal slopes of a forest road and to identify the type of relationship between decreasing sound intensity and increasing distance from the road. Materials and Methods: In order to measure the sound intensity, eight stations were used as acoustic measurement points along 20 km of the main one-way forest road of Teaching and Research Forest from Tehran University ,with low (2-5%) and high (8-11%) longitudinal slopes and Zero (roadside), 25 meters, 50 meters, 75 meters, 100 meters distances into the mass and downstream of the road and the axis of the road (closest situation to the car engine) were selected.The average sound level emitted from the Benztruck was 2624. This research was performed by the SL-4023SD digital audiometer with an accuracy of 1.5 dB and a resolution of 0.1 dB. The factors such as ,mean car sound level for a vehicle with constant engine volume, longitudinal slope in two levels, distance from the road in five levels were measured and analysis of variance was performed by GLM procedure whith using SPSS software. Results: In stations with longitudinal slope of the lower class by 58.7% and in stations with longitudinal slope of the upper class by 56.6%, a decrease in sound intensity was observed compared to the roadside. In all stations, the greatest decrease in sound intensity was recorded at distances of 0-25 meters from the roadside. In general, the type of relationship between decreasing sound intensity with increasing distance in longitudinal slope stations of the lower and upper class is logarithmic. Conclusion: According to the results, it can be seen that the longitudinal slope of the road did not have much effect on the intensity of sound emitted from the road. In this study, all variables, both independently and dependently, significantly affected sound penetration. The results of this study showed that the sound intensity decreased by moving away from the sound source. Careful design of road technical specifications such as longitudinal slope, maintenance of road pavement, the presence of vegetations on the roadside and prevent its destruction, maintaining and restoring the density of trees in the roadside mass, combined planting of broadleaf and coniferous species can be Somewhat reduce the intensity of sound emitted from the road.