As Delhi faces its annual winter surge in air pollution, the Decision Support System (DSS) for Air Quality Management has been reactivated. Developed by the Indian Institute of Tropical Meteorology (IITM), Pune, the DSS monitors pollution sources and forecasts air quality in the National Capital Region (NCR). This system is crucial as colder weather, shifting winds, and increased stubble-burning in neighbouring states typically worsen Delhi’s air pollution.
Current Pollution Scenario in Delhi
Recent data from DSS shows that farm fires contribute minimally to Delhi’s pollution. On some days, stubble-burning accounted for less than 0.5% of particulate matter (PM2.5) levels. Satellite observations confirm fewer fire events this year compared to previous years. The transport sector remains the largest pollution source, contributing nearly 17-19% of PM2.5. Residential emissions and industries follow as contributors.
Functionality of the Decision Support System
The DSS uses a numerical model with a 10 km grid to forecast pollution for up to five days. It quantifies emissions from Delhi and 19 surrounding districts. The system tracks contributions from eight emission sectors within Delhi and biomass burning in neighbouring states. It also simulates the impact of potential emission control measures on air quality.
Limitations and Challenges of the DSS
Currently, the DSS operates only during winter months. This limits its ability to monitor pollution year-round. The system relies on an emissions inventory from 2021, which affects the accuracy of source-specific pollution estimates. The Commission for Air Quality Management (CAQM) had suspended the DSS temporarily last year due to data accuracy issues. An updated emissions inventory is under preparation to improve the system’s precision.
Importance of Updated Emissions Data
Experts show the need for current emissions inventories and source apportionment studies to enhance DSS reliability. Real-time data is vital for enforcing targeted pollution control strategies. The Centre for Science and Environment (CSE) stresses that without updated inventories, forecasts and interventions may be less effective. IITM plans to incorporate new data once available.
Role of Satellite Monitoring
Satellite instruments like the Visible Infrared Imaging Radiometer Suite (VIIRS) play a key role in detecting fire events and surface vegetation changes. These data streams help validate ground-level pollution sources and support DSS modelling. Satellite monitoring confirms the relatively low incidence of stubble-burning fires this season.
Questions for UPSC:
- Taking example of Delhi’s air pollution management, discuss the role of technology in monitoring and controlling urban environmental challenges.
- Examine the impact of agricultural practices such as stubble-burning on air quality and public health in Northern India. Suggest sustainable alternatives.
- Analyse the significance of updated emissions inventories and source apportionment studies in formulating effective air pollution policies.
- Discuss in the light of air pollution control measures how inter-state coordination can improve environmental governance in the National Capital Region of India.
