Spatial analysis of air quality in Islamabad and Rawalpindi
Brick kilns are a major cause of air pollution in the outskirts of Rawalpindi and the federal capital of Islamabad.
Around 200 brick kilns operating in the vicinity of the Twin Cities burn 2,400 tonnes of coal for brick production. The smog produced by these brick kilns results in health issues from high air pollution and reduced vegetation coverage in surrounding areas, as well as reduced visibility causing road accidents and flight delays.
The AQI levels indicate that kiln industry is continuously deteriorating air quality due to emission of gases like carbon and sulfur oxides. People with heart and lung diseases are more vulnerable to these effects. The analysis could be improved by using real-time air quality monitoring.
Students from the School of Civil and Environmental Engineering at NUST analysed the effects of brick kiln emissions on the air quality of Islamabad and Rawalpindi using geographic information system (GIS) techniques. Download the complete report here, and read more for a summary.
Brick kiln emissions generate air pollution that extend over entire Twin Cities area
Initial data of brick kilns was provided by Pakistan Environment Protection Agency (Pak-EPA), and supplemented by satellite imagery for spatial analysis. As no real-time air quality data is available, the amount of daily production was used to calculate the concentrations of carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter (PM2.5).
GIS Hot Spot Analysis was used on this data set to identify higher concentration sites for each of the calculated values. The concentrations were used to generate a Air Quality Index (AQI) values. These AQI values were interpolated to generate a surface of Air Quality Index in Twin Cities and maps showing high pollution zones.
Two areas with particularly high concentrations of carbon monoxide and PM2.5 particulate matter are identified at:
- Jhangi Syedan and Sector I-16
- Between Gulzar-e-Qaid, Sudran Kalan and Gulberg Expressway
Further three areas with high concentrations of NOx are identified on Islamabad Highway at Tarnol, Dhok Patwarian and Sudran Kalan.
Brick kiln emissions are preventing vegetation growth in surrounding areas
To assess land cover changes we classified satellite imagery for various years. Brick kiln emissions are preventing vegetation growth in nearby sites. At these sites, barren land is most common and healthy vegetation is non-existent.
The results are presented as an indication of the impact on air quality from brick kiln emissions. The authors do not claim any accuracy of the data due to the unavailability of actual real-time air emission data.
Pakistan Air Quality Initiative (PAQI پاکی) is the first organization providing real-time air quality data for Pakistan, which would provide more accurate results for future studies.