What framework has SAFAR developed to predict air quality in the four metropolises?

The framework was first developed and implemented for Delhi in 2010, used in Pune from 2013 and expanded to Mumbai and Ahmedabad in 2015 (2017). SAFAR has chosen to demonstrate its predictive model in four different and contrasting microclimates of Indian cities.

The framework comprises six sophisticated components, including data from the network of air quality and weather measuring stations, an inventory of emissions to track the sources of pollutants, the air quality index among other things.

The chaotic nature and complexity of air pollution itself make forecasting a challenging task, especially in a city that is heavily influenced by meteorology due to its geographic location, which is taken into account in this work. We use 24/7 air quality and weather parameter measurements and scientific analysis to improve forecasting capabilities.

The SAFAR framework takes into account almost all pollutant levels – PM10, 1, 2.5, CO, NOx, SO2, volatile organic compounds, etc. – using automatic analyzers. With this framework, India no longer has to rely on international frameworks for forecasting air quality. This is developed according to the microclimatic conditions of the country. The SAFAR forecasting model is comparable to the framework of the United States Environmental Protection Agency (US-EPA).

What is the range of the air quality forecast?

We can give air quality forecasts 24, 48 and 72 hours in advance. And in the case of extreme pollution events such as dust storms or stubble fire problems, we have also started extended range forecasts that make predictions five days in advance. Air quality parameters are very dynamic, they have a very short lifespan. From a scientific point of view, it is impractical to make air quality forecasts more than five days in advance. From 2017 new things were added and the model was expanded to include further indigenization and outreach aspects.

How will air quality forecasting help citizens?

Using this forecasting model, all urban authorities can issue health warnings in a timely manner to warn citizens in advance of bad air days, which will help protect vulnerable groups from the serious health effects of air pollution. This framework is a one-stop solution for anything from air quality management to mitigation and also helps in formulating micro-specific air action plans based on solid scientific evidence. This framework can easily be replicated in 132 cities across the country with a population of over 10 lakh.

How many air quality monitoring stations does a city like Mumbai take to get accurate forecasts?

Many people say that there should be 100 or 200 monitoring stations in a metropolis. But I do not agree. It is practically impossible. These instruments are expensive. After the basic needs of the stations have been met, the money can be put into mitigation measures rather than the installation of new instruments.

On the other hand, an insufficient number of stations would give us distorted data and not really represent the city. According to research by the World Meteorological Organization, of which I was a representative from India, a city with a population between 50 lakh and 1 crore requires at least 10 to 12 stations. Next is the placement of the stations, which depends on the geography and land cover and use. There are six microenvironments that should be covered, namely transportation hubs, residential, industrial, updraft and downdraft locations, and in a coastal city like Mumbai one should be close to the coast.

What is emissions inventory and its role in predicting air quality?

An emissions inventory is nothing more than the recording of all pollutant sources in a certain area at a certain point in time. It contains information on the amount and type of air pollutants released into the air and provides information on the types of pollutant emission sources and their location. It is the primary input to the air quality predictive model. This data is also critical to policy-making, mitigation planners, and micro-level planning.

It is important to understand that the emissions in an area are not directly proportional to the air pollution in that area.

For example, one area has a source of emissions (fossil fuel burning) and the wind direction is east. Then a place that is even 3 km away from this emission source is heavily polluted, while an area that is 500 meters west of the source does not have high levels of pollutants. The forecast framework encompasses all of these elements.