Modelling of Air Pollution Caused by Traffic Flows in Manado City, Indonesia

Abstract

This study was aimed to determine the level of CO concentration due to traffic flows, know the traffic (vehicle) volume, traffic (vehicle) speed and wind speed, find out the relationship between traffic (vehicle) volume, traffic (vehicle) speed, wind speed and CO concentration using a regression model as well as examine the parameters influencing air pollution due to traffic flows. The primary data used in this study were the sample data of CO tested directly in the field and the sampling was done using Ecoline 6000 Gas Analyzer tool. The research sites covered 1) the segment of Sam Ratulangi Street in Manado representing the street locations with many multi-rise buildings and high building density, 2) the segment of Ahmad Yani Street in Manado representing the street locations with many trees, and 3) the segment of Pierre Tendean Street in Manado representing the street locations with open areas (beachsides). In this modeling, the independent variables were the total traffic volume, the average traffic speed as well as the wind speed and direction. The dependent variable was Carbon Monoxide (CO) with increased concentrations. Using the three independent variables, there were total 7 (seven) variable combinations used. Then, the obtained model was validated using the surveyed data. The maximum vehicle volume was 4,281.60 pcu/hour (pcu = passenger car unit) and the maximum vehicle speed was 32 km/hour. Meanwhile, the maximum wind speed generated was 7.5 km/hour and the maximum level of air pollution (CO) was 12.86 ppm (ppm = part per million). In this study, it was obtained the best model for each of the three locations. The results showed that the air pollution (CO) level of street locations with low wind speed, such as Sam Ratulangi street which is a closed area with many multi-rise buildings and high building density, was much higher than that of street locations with many trees growing in the median of streets with a distance of 1 meter from the edge of street pavement and also higher than that of street locations with open areas (beachsides). This is because a higher wind speed can disseminate or divide the concentration level of air pollution (CO) to various places. Air pollution control covers three stages namely the prevention, countermeasure, and recovery of air quality.