Urban versus rural emission contributions to air pollution in India

Alexandra Karambelas, of the University of Wisconsin-Madison, USA, explored how urban and rural air pollution combines to influence regional air quality in India, and how this might change under different policy conditions.

Alexandra Karambelas

Alexandra Karambelas

Introduction

Rapid economic development combined with weak air quality regulations has led to significant increases in emissions in India, and several Indian cities rank among the most polluted cities in the world. Due to its direct association with health impacts, fine particulate matter (PM2.5) is the main pollutant of concern, including both primary particulates like dust and soot, and secondary PM, which forms from chemical reactions of nitrogen oxides (NOx), sulfur dioxide (SO2), ammonia (NH3), and volatile organic compounds (VOCs). Different anthropogenic emissions sectors contribute to PM2.5, including transportation, a typical urban emission source, and traditional biomass cookstoves, a typical rural emission source. This study seeks to understand and evaluate the impacts these two spatially distinct emission sectors have on PM2.5 air quality in Northern India, and their respective potentials for improving the situation.

Methods

To evaluate contributions to PM2.5 air quality from traditional urban and traditional rural sources and to quantify their mitigation potentials, we develop several emissions scenarios around maximum reduction strategies for transportation (typical urban emission source) and domestic sector (typical rural emission source) to drive air quality conditions using the Community Multi-Scale Air Quality (CMAQ) model from the US Environmental Protection Agency. Emissions are generated from the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) Model and consist of a baseline scenario and projection used for present (2010) and future (2030) conditions assuming current legislation (CLE), a scenario assuming maximum feasible emission reductions in the domestic sector, and one scenario exploring leapfrog technology application to transportation scenario. These scenarios drive CMAQ sensitivity simulations, which are used to compare and contrast emission sector reduction techniques. To analyze distinct contributions from changes in emissions sectors, updated urban and rural activity and population information is applied to the baseline and sensitivity emissions scenarios.

Results

This study applies best available information on population distributions and domestic and transportation sector activity information to GAINS emissions in Indian sub-regions. Incorporating this information provides a basis for assessing changes in traditional urban (e.g. transportation) and traditional rural (e.g. domestic cookstoves) emissions and how they impact regional PM2.5 air quality. CMAQ output for a representative pre-monsoon month in 2010 has been validated; sensitivity simulations for 2030 have been initialized and once complete will provide a comparative assessment of PM2.5 concentrations determined by future reductions in transportation, traditional urban emissions, and domestic cooking, traditional rural emissions. Greatest changes in ambient PM2.5 concentrations suggest which sector will provide the greatest benefit to regional air quality improvements.

Supervisors

Gregor Kiesewetter and Chris Heyes, Mitigation of Air Pollution and Greenhouse Gases Program, IIASA

Note

Alexandra Karambelas, of the University of Wisconsin-Madison, USA, is a citizen of the USA. She was funded by the IIASA US National Member Organization and worked in the Mitigation of Air Pollution and Greenhouse Gases Program during the YSSP.

Please note these Proceedings have received limited or no review from supervisors and IIASA program directors, and the views and results expressed therein do not necessarily represent IIASA, its National Member Organizations, or other organizations supporting the work.


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Last edited: 03 February 2016

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