Source Apportionment Study of Ahmedabad City


Air Pollution is a growing problem in many Indian cities, including Ahmedabad and other major cities of Gujarat. Source Apportionment Study seeks to determine the sources of Air Pollution with its distribution. By using Engineering tools like Air Quality Modelling, Emission Estimation & Receptor Analysis. GEMI is determining the extent of Air Pollution in major cities of Gujarat. By means of the increased knowledge about reasons for problem, it will be easier to mitigate the Air Pollution problem in major cities of Gujarat.

Gujarat Environment Management Institute (GEMI) has first begun the Source Apportionment Study in Ahmedabad city, to ascertain the contribution of each source in city’s Air pollution. The aim of SAS is to scientifically analyze the samples in detail and to determine the type and concentration of the pollutants.

SAS is divided into 3 broad aspects:

  1. Emission Inventory
  2. Receptor Modeling
  3. Dispersion Modeling

Emission Inventory is a quantitative analysis of secondary and primary data collection of the pollutants emitted from different sources of a specific site and a specific time period. Emission inventory is carried out in 2 Km × 2 Km area around the air monitoring sites to predict the concentration of various pollutants received through receptor modeling. The Institute has rigorously completed the emission inventory of two residential grids namely; Paldi and Bapunagar, one commercial cum traffic grid namely; Income Tax and one industrial grid namely; Narol.

Receptor Modeling is the application of statistical methods to the identification and quantitative apportionment of air pollutants to their sources. Chemical speciation monitoring helps scientists understand the properties of the airborne pollutants at the receptor site(s) and to identify the emissions sources. The analysis results into quantifying the contribution of known emission sources.

Dispersion Modeling is the study that is used for projecting air quality profiles (iso-concentration plots) of the city, under different scenarios. It is also used to evaluate efficacy of various control options for evolving city-specific action plans for air quality improvements.



  • To quantitatively relate emissions to the characteristics of targeted aerosols at a specific receptor site
  • To evaluate the effectiveness of control strategies over time
  • To improve and validate emission inventories by determining major sources of air pollutants such as particulate matter and other contaminants
  • Strengthening environmental management, particularly at regional and local levels
  • Enhance the linkages between specific emissions sources and ambient air quality
  • Guiding the application of source models
  • Evaluating and improving source model results
  • Providing data to support the reduction of emissions through integrated strategies

Project Benefits

The project will have the following benefits:

  • Local people as they could know the major source contributing to their air pollution and the control measures to be taken for that,
  • Concerned Government and Private Consultants and Research Scholars as it generates large quantity of reliable primary data,
  • Concerned decision making authorities to make new policies or amend the existing policies such as City’s Air Quality Management Plan, Industrial Policy, Pollution Control Policy, etc.


  • Better knowledge about the sources and their strength will provide guidance to plan strategies for improving air quality of the city.
  • Identification of critically affected zones of the city, where attentions needs to be drawn for better control strategies.
  • The study will result in the identification and quantification of the emission source leading to serve as basis for better air quality management plan of the city.