A GIS- Based Approach for 2D Noise Modeling using 2D City Model

Abstract

Noise pollution of urban areas is one of serious problem. The local and urban authorities have to consider decision making processes for establishing residential, newly construction of hospitals, schools and maintaining the public places etc. The national environment act, no. 47 of 1980 provides limitation about noise emission of Sri Lanka. Road traffic is a major sources of community noise in metropolitan cities. Road traffic noise mapping is described in this research. The main objective of this research is finding the noise levels where it is less than 63dB and sub objective is finding the suitable interpolation technique for road traffic noise mapping. Noise maps can be used to monitor the issues of noise effects. Most of the noise maps are available today in two dimensional (2D) in which noise effect is presented in x, y plane. The preparing of noise map is depending on noise calculation model and 2D city model. The noise calculation model is based on amount of vehicles and speed, road type and noise absorption from the air etc. But in here considers only number of vehicles, speed of vehicles and noise reduction with the distance for the calculation of noise levels. Digital data layers which are digitized from satellite images, are used to prepare the 2D city model. The spatial analysis methods of GIS (Geographical Information Science) can play an important role to control noise pollution. GIS provides framework to integrate noise calculation models with spatial data. IDW (Inverse Distance Weighted) and Kriging interpolation techniques are used for the interpolation of noise levels. When checking the accuracy of noise levels with sample points, it recognized the IDW which better interpolation technique for noise mapping. There are 73% area is more than 63 dB sound levels and those area can’t be used for as silent areas in urban planning.