India’s New Earthquake Zonation Map by Bureau of Indian Standards

India has released a revised Seismic Zonation Map under the updated Earthquake Design Code by the Bureau of Indian Standards (BIS, 2025).
The map is based on scientific factors including active faults, maximum likely events, attenuation (reduction in earthquake intensity with distance), tectonics, and lithology (rock and soil types).

Details of the New Zonation

Earlier, the Indian landmass was divided into four earthquake zones: Zones II, III, IV, and V.
The revised map introduces a new highest-risk Zone VI, placing the entire Himalayan arc under it for the first time.
Previously, the Himalayan region was split between Zones IV and V.
Boundary towns between zones now automatically fall in the higher-risk category.
Hazard mapping in the new zonation prioritizes geological conditions over administrative boundaries.

India’s Earthquake Vulnerability

According to the new map, 61% of India’s land now lies in moderate to high hazard zones, up from 59% earlier.
Approximately 75% of India’s population now resides in seismically active regions.
The new map has important implications, such as encouraging retrofitting of buildings in high-risk areas.
It also discourages urban expansion on soft sediments or near active faults.
The map enforces uniform building standards across Himalayan states to reduce earthquake risk.

Government Strategies and Institutional Roles

The National Disaster Management Authority (NDMA) is responsible for setting disaster management policies.
State Disaster Management Authorities (SDMAs) are responsible for creating and implementing state-level disaster plans.
The National Seismological Network monitors earthquake activity across the country.
It also conducts research to develop earthquake early warning systems for timely alerts.