Noise Pollution Assessment in Sylhet City Corporation using Geographic Information System (GIS)

Noise pollution is a concerning factor that is increasing day by day in Sylhet City Corporation located in Sylhet division in Bangladesh. In this study, an attempt has been made to assess the noise pollution level in Sylhet city by comparing it with the standard noise level. Also, the outcomes from this study are compared with other studies from different countries. For measuring the noise level in decibel, BSWA 308 device was used in this study. Total 38 samples were taken from different geographical locations in Sylhet City Corporation. 38 samples provide 96 to 99% accuracy with a 95% confidence level (equal to or more than 36). The decibels value ranges from approximately 72 dB to 86 dB. From the observed data we calculated L10, L50, L90, Noise Climate NC = 12.7 dB, Equivalent Continuous Noise Level Leq= 77.18 dB, Noise pollution Level Lnp= 89.88 dB. Using Arc GIS software version 10.5 a contour map of the area was made, where every line in the contour map defines a specific decibel value. And the map was made with 2 dB intervals between the two corresponding contour lines. More than 30% of the study area is vulnerable to high levels of noise (>82dBA), and about 30% of the study area is the lower level of noise (<77dBA). After comparing the outcomes of noise level from this study it is observed that the noise level of this area has crossed the acceptable limit in all parameters.