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Noise pollution assessment in khoramabad to presenting executive strategies to control or reduce it

Kiani Sadr, M ; Sharif University of Technology | 2009

388 Viewed
  1. Type of Document: Article
  2. Publisher: 2009
  3. Abstract:
  4. Noise population is one of the most important environmental pollution cases that cause some troubles for inhabitants and employees in city limit and it is seriously considered as a hygienic risky case and even immunity in the world (Abaspour, 1992).The population of khoramabad city as Lorestan state capital has been 305590, on the basis of population estimate in 2003. It has three-city area and it is located at north-southern corridor of country (management and planning organization of Lorestan province 2004).The matter lead to great bulk of jam that pass through the passageway and linking line that cross through khoramabad city and caused diffusion of many kinds of pollution specially noise pollution. During last decade, khoramabad city developed rapidly in the field of population, expanding and placing of industries and work station, that all of these cases have effectively increased the noise rates in different parts of city. Noise pollution cause dangerous problems, such as nervous illness and related heart attack, heart beat and the increase of blood pressure, asthma, temporary deafness and constant deafness (Abaspour, 1992). Little attention has been paid to the field of noise pollution yet; so, it shows the necessity of present study. The main objectives of this study are: detecting the noise pollution map by using of Arc GIS, comparing the present situation with standard amounts, the delivery and complete of healthy questionnaires to determine the rate of individual satisfaction of noise rates in khoramabad city. A sound level meter device Bruel and kjaer 2230 model, made in Denmark and conformed by international standards has been used in this investigation. In this study the spread sources of noise pollution have bean determined by squared inspections and patrol in khoramabad city scale. In the investigated area, 19 cases were measured accidentally to determine the model volume and the number of noise measuring stations in city scale at round the clock. The number of cases and the number of stations have been obtained on the on the basis of related relations (number 1 equation) (khatami, 2003). n=Number of cases var2=Variance z=Safety factor d=Error D= Standard deviation n = (var ×Z 2)/d2 If d = (0.1 -0.01)D (1) and z=1.96 d=0.79 so: n = 385.03 n = 385 So a sample has been determined with 385.03 volumes for 95% confidence interval and error or mistake less than dBA 0/79 .Moreover in the case of increasing of the number of sample, activities error would be less than related amount. Regarding to the number of obtained through dividing the area menstruation by the number of samples. The place of their diameter intersection shows the place of measuring station. So area scale would be netted to symmetrical squares and measuring stations would be spread all over the city. Regarding the related stages, 30 measuring stations have been obtained and 8 more station have been added to related cases for more confidence with heavy traffic areas characteristics. To meet the number of necessary samples (385 samples) measuring must be done in every station about 10 times, but for comparing the day and night noise levels separately and also for investigation the current of noise level changes, measuring has been done one day per week during spring and summer in every season for one week in different days. So one sample in day and one sample at night have been taken in each station and every week and generally the number of taken samples from every station have been increased to 28 samples and the number of whole samples amounts to 1064 ones from city scale which lead to high accuracy of activities equation number (2) has been used for calculating Ldn rate at measuring stations. Ldn = 10Log{1/24[(15 x 10LeqdT/10)+ 9 x LeqnT+10/10]}) (2) Noise level equivalent was more than standard amounts of Iran noise on the basis of measuring results in spring and summer Seasons in all of the noise sampling stations in khoramabad. All of the stations that have highest Leq in spring season have highest amounts of Leq in summer season too. The rate of this amounts in summer have been more than spring season also Baharestan Blvd station has greatest amounts of mean of daily Le() and greatest mean of ,nightly Leq and the greatest mean of Ldn in both spring and summer seasons which has also administrative-commercial usage. Mean of daily Leq of this station in spring and summer seasons have standard deviation in the following manner: 4,2 and 1,2 dBA. The mean of nightly Leq of this station in spring and summer seasons have standard deviation in the following manner: 4,20 and 1,21 dBA. Generally daily variation of mean of the noise measured parameters was very few in khoramabad in spring and summer seasons. This shows the nearness of amounts. 11 stations out of 38 stations (5 stations with high noise amounts and 6 stations with low noise amounts) have been chosen to determine the amounts of(L90,L50,L10,L1) LN during environmental noise measuring in khoramabad city. These amounts have been taken by drawing SPL diagram -cumulative frequency for stations. And also noise traffic criteria was calculated by equation number (3) (Safarzade,2003): TNI(dBA) = L90 + 4(L10 -L 90) -30 (3) The results of related calculation have been presented in Table (1) and (2). In next stage the public health questionnaires were delivered at measuring stations. In this investigation, 500 questionnaires accidentally have been completed at measuring stations of noise level equivalent .250 questionnaires in spring 2007 and 250 questionnaires in summer 2007 have been delivered and completed. SPSS software has been used for statistical analysis of obtained results of noise parameters measuring in determined stations. The measuring results have been analyzed by using of Arc GIS software and at the end maps of noise levels have been tracing for spring and for summer seasons and separately for SPL, Leq, Lmax, L min, Ldn parameters too. Finally, AutoCAD software has been used for revamping of streets geometric construction. Obtained results shows that there is significant difference between mean of noise level equivalent of nightly noise in spring and also summer seasons. There is also significant difference between mean of Ldn in summer season. In view of noise level equivalent of daily and nightly noise there is no significant difference between present stations in three regions of khoramabad municipality. The total rate of noise pollution is more intensive in southern and central parts of city. Also questionnaires results shows that, totally 69/7 percent of citizens have brought up the existence of bothersome noises around there that most of it is related to automobile cars and honking. Of course, the noise pollution made by the traffic jam of automobile and taxi in some busy places is more than other vehicles. The results obtained from questionnaires statistical analysis showed that there was no significant difference between the spring and summer. Furthermore, the relations between different groups of questionnaires have been investigated for the both seasons by using of chi-square test. These cases are consisting of different aspects: there is no significant difference between different age group and interrupted sleep, dissatisfaction and irritation indexes such as existence of concentration, disorder of dialogue, erupt of anger, erupt of headache and restlessness, obtained results of questionnaires investigation shows that people dissatisfaction rate of traffic uproar in stations with high noise level by far is more than the others. There was significant relation between men group variant and erupt oranger (Pvalue=. /041) and women group variant and headache variant resulting from traffic uproar (Pvalue=. /041) in spring season. Also there was significant relation between men group variant and erupt of anger(Pvalue=./041)and women group variant and headache variant resulting from traffic uproar(Pvalue=. /043) in summer season. The results illustrated that, jam and the difficulties related to the traffic problems are the most important reasons of increasing the noise pollution in khoramabad city. To conclude, suitable solutions have been offered by measuring and comparing the obtained results, the results taken from healthy questionnaires and the related methods to decrease noise pollution used in other countries. Some of these solutions are: •Making some streets more widening •Reformation of the pedestrian system (pedestrians and side walks) in central parts of city. •Educate and promote the status of traffic cultivation. •Supply equipment for transportation system and city traffic and traffic control. •Reformation of public transportation system using city bus. • Design and affix the noise barrier in Shariati Blvd, Daneshju Blvd, Baharestan Blvd and Enghelab streets. • Doing research for proper site selection of noise barriers in khoramabad city and affixing noise barriers in highways side specially in Shariati Blvd, Daneshju Blvd, Baharestan Blvd, Enghelab streets and over crowded places and buildings according to correct height and length and paying attention to their aesthetics and proficiency. •Making sound proof the external layers of buildings and use of two-layered glasses and use of absorbers in buildings and the observance of necessary distance of highways side during constructing buildings and prohibition of family unit construction in highways borders
  5. Keywords:
  6. Khorram abad ; Noise alignment maps ; Noise pollution ; Questionnaire ; Strategy
  7. Source: Journal of Environmental Studies ; Volume 35, Issue 50 , 2009 , Pages 83-96 ; 10258620 (ISSN)
  8. URL: https://www.sid.ir/en/journal/ViewPaper.aspx?id=159583