dc.description.abstract |
Noise generally is known as unwanted sound, which can adversely impact the quality of life in
urban areas across the globe. In Dire Dawa, which is one among the major industrial cities in
Ethiopia, there are several indicators that noise pollution is really a problem. The purpose of
this thesis was to assess noise pollution level from various sources at 12 different purposely
selected urban locations of Dire Dawa city. In this study, the continuous noise monitoring was
carried out for 2-3 times per day during two consecutive days at each locations under four
zones viz. Residential, Silent, Commercial and Industrial zone during winter season of 2020.
Noise pollution indices viz. L10, L50, L90, noise climate (NC), equivalent continuous noise
level (Leq), noise pollution level (LNP) and traffic noise index (TNI) were computed for all
zone areas. Both descriptive and inferential statistics was used for the analysis of the data
obtained through digital sound level meter and analyzed using a one way ANOVA. The results
of the analysis revealed that in all selected locations under each zone, the recorded noise
pollution level values were above the standard permissible limits 45, 55, 65 and 75 dB(A) near
Silent, Residential, Commercial and Industrial zone, respectively as laid down by WHO.
Moreover, comparison analysis indicated that there is statistically significant difference in
noise pollution level among the four zones as well as within locations. The result further
revealed that the noise level was higher at industrial and followed by commercial zones
compared to residential and silent zones. The major sources of noise pollution in these zones
were high volume traffic flow, workshop machinery activities, vehicle horn, commercial
activities, use of loud speakers from religious centers. Based on the results of this study, it was
recommended that the precautionary measures should be implemented by local government to
prevent or abate the alarming condition of noise pollution in Dire Dawa city in order to save
people from the health risk of noise pollution. |
en_US |