Seismic Zoning of India: Sorting the Country by Risk

Not every part of India faces the same earthquake risk. This article covers how the country’s seismic zoning system sorts that risk, and a recent attempt to raise it.

Sorting the Country by Risk

IndGeo0050

2002

IS 1893 Established

Set the current four-zone system, Zone II to Zone V

2016

IS 1893 Revised

The code still governing India’s seismic zoning today

NOV 2025

Zone VI Proposed

A new highest-risk zone for the entire Himalayan arc

MARCH 2026

Zone VI Withdrawn

BIS rolled it back, citing construction cost concerns

As of March 2026: India’s seismic zoning is back to the four-zone IS 1893:2016 system.

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Timeline

• 2002: IS 1893 (Part 1) established India’s current four-zone seismic system, Zone II through Zone V.
• 2016: The Bureau of Indian Standards (BIS) revised the code. This 2016 version still governs India’s seismic zoning as of March 2026.
• November 2025: BIS released a new code, IS 1893:2025, adding a highest-risk Zone VI covering the entire Himalayan arc.
• March 2026: BIS withdrew the 2025 code after the Ministry of Housing and Urban Affairs raised construction-cost concerns. IS 1893:2016 came back into force.

Must Know

• India’s seismic zoning system, set by the Bureau of Indian Standards (BIS) under IS 1893, sorts the country into earthquake-risk zones.
• The current system has four zones: Zone II (low risk), Zone III (moderate), Zone IV (high), and Zone V (very high).
• Zone V covers the Himalayan belt, Northeast India, parts of Jammu & Kashmir and Uttarakhand, and the Rann of Kutch.
• About 11% of India’s area falls in Zone V, 18% in Zone IV, 30% in Zone III, and the rest in Zone II.
• In November 2025, BIS briefly added a Zone VI for the entire Himalayan arc, before withdrawing it in March 2026 over cost concerns.

Good to Know

• Delhi falls in Zone IV, despite sitting far from the Himalayan plate boundary, due to nearby active fault lines. Mumbai‘s Konkan coast also falls partly in Zone IV.
• The 1993 Latur earthquake, on the supposedly stable Deccan Plateau, and the 2001 Bhuj earthquake both led to significant upward revisions of the zoning map.
• The proposed Zone VI carried a much higher design-safety factor than Zone V. That would have meant substantially stronger, and more expensive, building codes across the Himalayan arc.

Test Yourself

Please wait…

1. India’s current seismic zoning system classifies the country into how many zones?

Three

Five

Six

Four

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Great to Know

• Seismic zoning exists to calibrate building codes to actual local risk, not apply one national standard everywhere. A Zone II building needs far less earthquake-resistant design than a Zone V one.
• The 2025 Zone VI episode shows how technical risk assessment and economic cost can pull in opposite directions. The scientific case for a higher-risk zone didn’t survive contact with construction-cost politics.
• Zoning revisions after Latur and Bhuj show the system responding to real events, not staying frozen at its original 2002 boundaries. Unexpected earthquakes in “stable” zones forced real reassessment.
• A quick rollback within months, rather than years, suggests the 2025 code was pushed through with limited stakeholder consultation. That is one of the reasons MoHUA itself cited for reversing it.