What Happened
- India's revised seismic zonation map and updated earthquake design code (IS 1893:2025), released by the Bureau of Indian Standards (BIS) in late 2025, have been withdrawn by the Centre following strong pushback from multiple Union Ministries and infrastructure sector agencies.
- The revised framework had, for the first time, classified the entire Himalayan arc — from Jammu & Kashmir and Ladakh to Arunachal Pradesh — under a newly created highest-risk Zone VI, replacing the older split classification across Zones IV and V.
- The withdrawal was driven primarily by concerns from construction industry stakeholders and infrastructure ministries about a projected 15–30% spike in building costs in high-risk zones, arising from stricter earthquake-resistant design requirements.
- Experts and disaster risk specialists have expressed alarm, warning that rolling back a scientifically validated and more accurate hazard map undermines decades of progress in earthquake preparedness and exposes millions of lives to preventable risk.
Static Topic Bridges
India's Seismic Zonation System and BIS Standards
India's seismic zonation is defined by the Bureau of Indian Standards (BIS) through the earthquake design standard IS 1893 (Criteria for Earthquake Resistant Design of Structures). The map divides the country into seismic zones based on expected ground shaking intensity, with each zone requiring progressively stronger and costlier building specifications.
- Previous zone system (IS 1893:2016): Four zones — Zone II (least hazard), Zone III, Zone IV, Zone V (highest)
- Revised system (IS 1893:2025): Introduced Zone VI as a new highest category; entire Himalayan arc reclassified into Zone VI
- Methodology shift: From deterministic historical-epicentre-based approach to Probabilistic Seismic Hazard Assessment (PSHA) — a globally accepted, more accurate method
- BIS: Established under the Bureau of Indian Standards Act, 2016; under Ministry of Consumer Affairs, Food and Public Distribution; sets national standards across sectors
- 61% of India's landmass falls under moderate-to-high seismic hazard zones even under the previous classification
Connection to this news: The rollback means IS 1893:2025 is suspended and IS 1893:2016 reverts as the operative standard — effectively downgrading the officially recognised hazard level for the Himalayan belt despite scientific evidence of higher risk.
Himalayan Seismicity and Tectonic Setting
The Himalayas are formed by the ongoing collision between the Indian Plate and the Eurasian Plate — one of the most active tectonic boundaries on Earth. This collision zone accumulates enormous seismic stress over decades, periodically releasing it in large earthquakes. Long-locked fault segments in the Himalayan arc are capable of generating earthquakes of magnitude 8.0 or higher.
- Key fault systems: Main Central Thrust (MCT), Main Boundary Thrust (MBT), Himalayan Frontal Thrust (HFT)
- Historical major earthquakes in the Himalayan belt: 1905 Kangra (M7.8), 1934 Bihar-Nepal (M8.0), 1950 Assam (M8.4), 2001 Bhuj (M7.7 — Deccan region), 2015 Nepal (M7.8)
- States in Zone V (previous): Jammu & Kashmir, Himachal Pradesh, Uttarakhand, parts of Northeast India, Andaman & Nicobar Islands
- Gap earthquakes: Seismologists have identified "seismic gaps" in the central Himalayas where large earthquakes are overdue
- Urban exposure: Rapidly growing Himalayan cities (Dehradun, Srinagar, Shimla, Gangtok) face high risk; most buildings predate modern earthquake codes
Connection to this news: The revised Zone VI classification was directly justified by the accumulated seismic stress in the Himalayan arc and the gap between scientific risk assessment and the previous official zoning — the rollback ignores this scientific consensus.
National Disaster Management Authority (NDMA) and Disaster Risk Reduction Framework
India's disaster risk governance is anchored by the Disaster Management Act, 2005, which established the National Disaster Management Authority (NDMA) — chaired by the Prime Minister — as the apex body for disaster preparedness, mitigation, and response. Seismic risk reduction is a core mandate of NDMA, encompassing earthquake-resistant building codes, public awareness, and emergency preparedness.
- NDMA: Established under Disaster Management Act, 2005; PM as ex-officio Chairperson
- State Disaster Management Authorities (SDMAs): Chaired by respective Chief Ministers
- Sendai Framework for Disaster Risk Reduction (2015-2030): India is a signatory; commits to reducing disaster risk and losses through science-based risk assessment
- National Building Code of India (NBC): Complementary to IS 1893; specifies construction standards for earthquake resistance
- Retrofitting challenge: Most existing buildings in Himalayan cities were built before modern codes; retroactive compliance is vastly more expensive
Connection to this news: Rollback of the updated seismic map directly conflicts with India's Sendai Framework commitments and NDMA's mandate to enhance disaster resilience based on the best available science.
Key Facts & Data
- IS 1893:2025 introduced Zone VI — first new highest zone since the current classification system was established
- Entire Himalayan arc (~2,500 km) reclassified into Zone VI under IS 1893:2025 (now rolled back)
- Previous classification: Himalayan belt split across Zones IV and V (IS 1893:2016 remains operative post-rollback)
- Projected cost increase from Zone VI compliance: 15–30% higher construction costs in affected areas
- 61% of India's landmass is under moderate-to-high seismic hazard zones
- Methodology of IS 1893:2025: Probabilistic Seismic Hazard Assessment (PSHA) — replaces deterministic historical-epicentre approach
- Himalayan arc fault segments: capable of M8.0+ earthquakes; multiple "seismic gap" zones identified by researchers
- NDMA: Chaired by PM; established under Disaster Management Act, 2005
- BIS: Under Bureau of Indian Standards Act, 2016; Ministry of Consumer Affairs