Parts of Delhi and Kolkata, especially areas along the rivers Yamuna and Hooghly respectively, would face a greater impact in the event of an earthquake, according to a study conducted by the government.
While most of Delhi face "least" and "moderate" risk, areas like the Lutyens Zone and north campus of Delhi University fall in "high" and "very high" seismic risk hazard index, the study says.
In the City of Joy, earthquake can pose a threat to Salt Lake area and places along the Hooghly river bank.
The Report on Seismic Hazard Microzonation of NCT of Delhi and Kolkata done by the Ministry of Earth Sciences describes threat levels in different parts of the two cities in the event of an earthquake.
The high risk zone in the national capital, mostly in patches, are concentrated in east, central and northern parts.
Areas like Gita Colony, Sarita Vihar, Shikarpur, Paschim Vihar, Wazirabad, north campus, Rithala, Rohini, Jahangirpuri, Bawana, Karol Bagh and Janakpuri fall under the "very high risk" index. Most of these areas lie along the Yamuna.
Places like Hauz Khas, Burari, Najafgarh and IGI Airport fall under "high risk" zone, while AIIMS, Vasant Kunj, Naraina, JNU campus and Ashok Vihar are among the safest places and fall under the "least" seismic risk index.
"A study is being conducted for 30 more cities. We will bring out a similar report for other cities as well," Harsh Vardhan, Minister for Earth Sciences, said during the launch of the report.
The report is based on a study of various aspects like the kind of rock which is there in a particular area, groundwater level, soil quality and how it can affect structures in case of an earthquake.
Delhi falls in Zone 4 in terms of the threat perception from earthquakes.
"Delhi is not a major source of earthquake but it is definitely prone to earthquakes occurring in the Hindukush Mountain range and the Himalayas. The Himalayas are as close as 180 km from Delhi," said Vineet Kumar Gahalaut, Director of National Centre for Seismology.
This was observed when major earthquakes hit the Hindukush in Afghanistan and Nepal.
B K Bansal, an advisor looking after projects related to seismology in the Ministry, said the national capital does not face major risk but precautions must be taken by retrofitting houses.
Microzonation would benefit in disaster mitigation and management authorities, urban development authorities, planning, design and construction agencies, risk assessment to existing life and property, defence installations, heavy industry, public utilities and services.
"We will be giving the report to all concerned agencies so that they can take necessary steps to avoid any major catastrophe," Vardhan said.