New Zonation Framework
India’s Revised Seismic Risk Landscape: India has issued a revised Seismic Zonation Map under the updated Earthquake Design Code 2025 of the Bureau of Indian Standards (BIS). The new framework moves away from older boundary-based classification and aligns with geological realities. It reflects the latest understanding of tectonics, fault behaviour, and attenuation patterns.
The earlier system classified India into Zones II, III, IV, and V. The new map adds a higher-risk Zone VI, marking a crucial shift in national earthquake preparedness.
Static GK fact: India follows the IS 1893 standard for seismic design, first introduced in 1962.
Introduction of Zone VI
A major change is the placement of the entire Himalayan arc under Zone VI, which is the highest risk category. Previously, these regions were divided between Zones IV and V, creating gaps in safety measures. This unified classification ensures uniform hazard perception and building code enforcement across the arc.
Boundary towns that fall between two zones now automatically shift to the higher-risk category. This eliminates administrative ambiguity and prioritises scientific hazard evaluation.
Static GK fact: The Himalayas are one of the world’s youngest fold mountains, formed by the collision of the Indian and Eurasian plates.
India’s Earthquake Vulnerability
The revised zonation increases the mapped hazard coverage. An estimated 61% of India’s land falls under moderate to high hazard zones, compared to the earlier 59%. An even more significant figure is that 75% of India’s population now resides in seismically active regions.
These changes highlight long-term challenges for infrastructure, especially in growing urban centres located near active faults or soft sediment basins.
Static GK Tip: The Indo-Gangetic Plain is one of the world’s most sediment-filled basins, significantly amplifying seismic waves.
Implications for Infrastructure
The new map will push states and developers to strengthen retrofitting efforts in high-risk areas. Expansion in regions with soft sediments, steep slopes, or proximity to active faults may be restricted. Himalayan states, which face the highest risk, are expected to adopt uniform building codes aligned with Zone VI standards.
Public infrastructure projects must now prioritise earthquake-resilient design, especially in hill towns, border regions, and major transport corridors.
Government Preparedness Mechanisms
The National Disaster Management Authority (NDMA) provides the policy framework for disaster management, while each State Disaster Management Authority (SDMA) prepares and executes local action plans. Their coordinated role becomes more important under the revised zonation.
The National Seismological Network continues to monitor seismic activity and conduct research on early warning systems. Strengthening this network will support faster alerts and improved risk communication.
Static GK fact: India’s first digital seismograph network was established in the 1990s.
Static Usthadian Current Affairs Table
India’s Revised Seismic Risk Landscape:
| Topic | Detail |
| New BIS Map | Revised Seismic Zonation Map under Earthquake Design Code 2025 |
| Highest Risk Zone | Zone VI covering entire Himalayan arc |
| Previous Zones | II, III, IV, V |
| Hazard Coverage | 61% of land in moderate to high zones |
| Population Exposure | 75% of population in active regions |
| Mapping Basis | Faults, tectonics, lithology, attenuation |
| Policy Authority | NDMA sets national disaster policies |
| State Role | SDMAs prepare implementation plans |
| Monitoring Network | National Seismological Network |
| Infrastructure Impact | Retrofitting and stricter building norms in high-risk areas |
