An Evaluation of Spatial and Temporal Acoustical Patterns of Roadway Traffic through GIS Techniques

Abstract

Most of the environmental tribulations is embedded in a spatial matrix. Such location disparities in environmental quality resulting from the patterns of transportation and land use are legitimate themes of transportation engineering, environmental management and geographic inquiry. In this context, the empirical data of mega cities of developing countries could help in tracing the relationship between relevant urban, environmental and transportation factors. Several populous cities of the developing world are currently facing the issue of environmental degradation. For instance, Karachi, the largest city of Pakistan is growing at the rate of 4.2 percent per annum [l](UNEP, 1999) where the vehicular noise and blowing of horns have increased alarmingly and is up to 30 to 35 dB (A) above the internationally accepted tolerable thresholds [2](Mehdi, 2002). Periodic monitoring is the only solution to assess the spatial as well as temporal variations of noise pollution within the city. The growing trends and levels of successful implementation of environmental laws could only be ascertained thereafter. Geo-informatics enables scientists, engineers and decision makers to monitor, model and predict the spatio-temporal acoustical data. However, this functional link: is missing in many developing countries due to lesser comprehension of 'Geo-informatics' and inadequate financial resources. In this research paper, a methodological study has been presented for exploring spatio-temporal variations of traffic induced noise through the analytical tools available in state of the art Geo-informatics, in view of a city of a developing country. Generating real world acoustic data, georeferencing, transformation into Geographical Information System (GIS) and finally construction of mesogeographic thematic maps has been the procedural steps. Sampling methods, spatio-temporal modeling procedures and interpretation of resultant maps are the key areas of discussion. It is anticipated that similar concept can be applied in other parts of the developing world.