Q: Mumbai, Delhi and Kolkata are the three mega cities of the country but the air pollution is much more serious problem in Delhi as compared to the other two. Why is this so?
Though all the mega cities in India suffer from the problem of air pollution at alarmingly high levels due to growth in number of personal vehicles, increasing populations and effects of rapid urbanization, but, the problem is specifically more in Delhi as compared to the cities of Mumbai and Kolkata. This can be attributed to the following factors:
- Delhi is landlocked when compared to Mumbai and Kolkata so the level of pollution is more as the level of particulate matter and pollutants is not able to get discharged into the surrounding areas. Mumbai is surrounded by sea on three sides and Kolkata on two sides so the pollutants are discharged into the surrounding large water bodies and the level of pollution over these cities comes to be less when compared to Delhi.
- The highly variable winds near the coast may sweep pollutants out to sea on a land breeze but then bring them back with the sea breeze. The variations in sea breeze circulation also have distinct effect on the pollutant transport and dispersion mechanisms in the coastal urban areas. Whereas in case of Delhi the principle of continentality occurs thus in winters high pressures develop due to which the pollutants remain near to the ground.
- Due to the landlocked nature of location of Delhi, during winter months fog occurs in Delhi which further adds to the problem of pollution.
- The next reason can be the increasing pollution from nearby industrial areas in close proximity of Delhi like Faridabad, Okhla and Noida industrial regions, whereas this is not the case with either Mumbai or Kolkata. The pollution level from the industries in nearby areas of Delhi has added more to the problem of Delhi.
- Moreover, the burning of paddy crops and other crops in Punjab and Haryana during winter months also is responsible for pollution, whereas no such incidents are reported in other two cities.
Thus, the problem of pollution in Delhi can be attributed to the geographical location of Delhi when compared to Mumbai and Kolkata. The need of the hour is to devise some mechanisms which can help to bring down the level of pollution in the city such as using less pollution causing vehicles, developing a good mass transit system and controlling waste effluents from industries.