Urban Emissions

Air pollution has become a significant environmental hurdle in Indian cities and throughout various states. This challenge's intricacy arises from numerous emission sources, including industries, vehicles, generator sets, domestic fuel combustion, roadside dust, construction activities, and more, amidst diverse meteorological conditions across climatic zones. The organisation’s air quality forecasting system in India assimilates pollution contributions across national, regional, and urban areas. This is aimed at bolstering a comprehensive air quality management strategy and an immediate health alert system.

The emissions from road transport exhibit variations in both geographical distribution and timing. The scope of this analysis covers an extensive area, including 640 districts, 36 states, and 22 cities (which are subsets of certain states). This area encompasses a mix of residential, industrial, commercial, agricultural, barn lands, and water bodies. Moreover, different vehicle types (such as two-wheelers, three-wheelers, four-wheelers, buses, and trucks) exhibit distinct behaviours, posing a challenge in accurately segregating the estimated total emissions across various locations. The findings from this road transport emissions study have been documented in a published journal article in Energy Policy. This research delves into the expected growth rates in vehicle sales, their impact on urban air quality, and outlines necessary strategies for improving air quality in the urban transport sector.

The challenge of household energy consumption (HEC) and its impact on indoor and outdoor air pollution is a significant concern in India, given the substantial population exposed to such pollution daily. To address this, a comprehensive study was conducted to delve into HEC and estimate its role in contributing to ambient air pollution using a source modelling approach, encompassing both emissions and dispersion modelling techniques. The emissions arising from HEC were segregated into four main categories: (a) cooking, (b) lighting, (c) space heating, and (d) water heating. The emission factors related to various fuel categories were derived from studies compiled by the Indian Institute of Technology Bombay, Mumbai.

The sources of emissions from dust storms are natural and play a crucial role in regional chemical transport models, such as CAMx. These storms not only impact ambient particulate concentrations but also provide additional surfaces that support photochemical reactions. In the current framework using WRF-CAMx chemical transport modeling, the organisation has developed specific modules to utilise the most up-to-date resources for calculating dust storm emissions:
1. Land use patterns are established by utilising MODIS fields, integrated into the WRF pre-processing package, allowing for the differentiation of arid and semi-arid regions.
2. Meteorological fields are obtained from WRF simulations conducted in both hindcast and forecast modes. A summary of average surface winds during daytime and nighttime for upcoming days is detailed below.

ATMoS is the organisation’s internally developed dispersion modeling system, which is utilized to generate source-receptor transfer matrix (SRTM) for numerous urban and regional settings.

To aid in Delhi's air pollution control, the organisation predicts the levels of all key pollutants for the coming 72 hours. The modeling area encompasses Delhi and its surrounding satellite cities, spanning 80 kilometers from North to South and 80 kilometers from West to East, with a detailed spatial resolution of 0.01 degrees (~1 kilometer) and an hourly temporal resolution. The meteorological and concentration data used in the models are refreshed daily around 7:00 PM IST.