Delhi’s car restrictions may not reduce pollution: Indian-American expert

Bengaluru, Jan 12 (IANS) The odd-even restrictions for cars being experimented with in New Delhi will not work to improve the national capital’s air quality due to its geographical location and the long-range airmass floating in from north and northwestern India, says an Indian origin US professor who has been analyzing satellite data.

The odd/even restriction will be of great help in reducing the traffic but wouldn’t do much to reduce concentrations of fine particles, Ramesh Singh, a professor at Chapman University in California, told IANS in an e-mail interview during an extended visit to Varanasi, from where he obtained his B.Sc., M.Sc. and PhD degrees.

“My views are supported by data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) satellite,” said Singh, who was formerly a professor of civil engineering at the Indian Institute of Technology-Kanpur.

According to Singh, Aerosol Optical Depth, which is a measure of air pollution, retrieved from MODIS satellite data over Delhi during December 1, 2015, to January 10, 2016, shows that the pollution level remains high and there is no reduction in PM2.5 fine particles after the odd-even restrictions were put in place.

Singh said that Delhi Chief Minister Arvind Kejriwal has tried to copy from Beijing, where some car owners in different areas are allowed to drive only on specific days “to cut down the flow of traffic, not because of pollution”.

“Delhi and Beijing have similar sources of pollutants (coal-based power plants, brick kilns, industry and the like), but we should not compare whether PM2.5 is higher in Delhi or Beijing because the geographical situation is different,” Singh said.

“Cities in the Ganges basin have the lofty Himalayas in the background and, again, whereas in Beijing the emissions get dispersed in all directions, in Delhi pollutants come from western parts and occasionally from eastern parts of the basin.

“Delhi is located in the Ganga basin and during winter time, depending upon the weather conditions, dense haze, fog and smog are formed and moves in the Ganga basin. Therefore, sometimes dense fog/haze/smog is seen in Delhi, Kanpur, Lucknow, Banaras and Amritsar.

“Also, during the winter season the wind, which is mainly westerly, brings pollutants from Pakistan, and from Punjab and Haryana, northern regions of India. All these pollutants cannot be stopped due to the towering Himalaya in the north,” Singh said.

Therefore, there is continuous flow of airmass from west to east and Delhi gets affected through the long range transport of pollutants from the west and also from the foothills of the Himalayas where the burning of wood is prevalent during the winter season, Singh said.

Emissions from vehicles in Delhi mix with the fine particles in the airmass coming from the western side and the strong mixing of the two affects the solar radiation budget and highly impacts Delhi’s atmospheric chemistry, which may create other atmospheric problems, Singh said.

“While the effort of the Delhi government must be welcomed, a detailed feasibility study is needed to manage plying of vehicles in Delhi to curb the local pollution,” he added.

Leave a Reply

Please enter your comment!

The opinions, views, and thoughts expressed by the readers and those providing comments are theirs alone and do not reflect the opinions of or any employee thereof. is not responsible for the accuracy of any of the information supplied by the readers. Responsibility for the content of comments belongs to the commenter alone.  

We request the readers to refrain from posting defamatory, inflammatory comments and not indulge in personal attacks. However, it is obligatory on the part of to provide the IP address and other details of senders of such comments to the concerned authorities upon their request.

Hence we request all our readers to help us to delete comments that do not follow these guidelines by informing us at Lets work together to keep the comments clean and worthful, thereby make a difference in the community.

Please enter your name here