Date of Award

6-2010

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Dr. Munjed Maraqa

Second Advisor

Yaser E. Hawas

Third Advisor

Dr. Basil Daham

Abstract

Road traffic is considered a major source of air pollution in congested areas. The number of vehicles in Al Ain city has increased over the last seven years due to population and economic growth. The rapid growth in motor vehicles in Al Ain could contribute to an increased level of urban air pollution that may threaten human health, damage ecosystems and influence climate. No study has been conducted to assess the effects of roadway traffic on air quality in the city of Al Ain. Such study will further be useful as a baseline for future planning and development of the city. Therefore, the present study was designed to investigate the impact of traffic volume on the ambient air quality of Al Ain.

Data of several air pollutants including PM10, SO2, NO2, CO, O3 and HCs were collected during 2007-2009, using two fixed air monitoring stations in two areas of different traffic congestion levels; one in the downtown area and the other in a residential area in Al Ain. The levels of these pollutants were compared with Abu Dhabi Air Quality Standards. Also, the relationships among these pollutants and between pollutant level and meteorological conditions were investigated.

Data on traffic counts at the downtown area were collected from the RTTSRC at the UAE University. These traffic counts were used to predict the air pollutant emissions from traffic volume using Synchro and IVE models. The Box Model was then used to estimate ambient pollutant concentration using the estimated emissions. Predicted pollutant levels were then compared with the actual levels measured at the monitoring stations.

The results of this study indicate that the concentration levels of most of the air pollutants were below Abu Dhabi Air Quality Standard at both stations, except for PM10 which exceeded the Abu Dhabi Air Quality Standard many times. It was also found that there are statistically significant variations in pollutants level between the residential and the downtown area. The higher pollutants levels at the downtown area are attributed to the influence of road traffic volume and other population-related activities. Moreover, the Al Ain residential area had better air quality than Al Ain downtown area according to the air quality index. It was also found that temperature correlates well with some air pollutants.

This study showed that the traffic in the downtown of Al Ain contributes in the range of 15% to 35% of CO, with an average of 25%. The traffic also contributes in the range of 36% to 69% of NOx, with an average of 57% and it contributes only in the range of 0.4% to 0.8% of PM10, with an average of 0.5% levels. The low contribution of traffic to pollutant level (as is the case for CO and PM10) indicates that other sources including commercial activities or open burning in nearby farms play a major role in determining the ambient concentration of these pollutants in the downtown of Al Ain. Finally, this study indicated the importance to develop a proactive traffic management mitigation measures for Al Ain downtown to manage traffic congestions and hence improve the air quality.

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