(Important for OPSC OAS Examination – Disaster Management, Geography, Urban Planning, Infrastructure Development)

Introduction

The Government of India recently rolled back the proposed revision of the country’s earthquake zoning map prepared by the Bureau of Indian Standards (BIS). The revision was intended to improve the scientific accuracy of earthquake risk assessment across India. However, concerns were raised regarding the economic implications, feasibility of implementation, and potential impact on infrastructure and housing costs. The episode highlights a broader policy dilemma—how to strengthen disaster preparedness without imposing unsustainable financial burdens on development and urbanisation.

Purpose of Earthquake Zoning

Earthquake zoning is an essential component of disaster risk management.

• It divides regions of a country according to their level of seismic risk.

• The classification helps guide several policy and planning decisions, including:

  • Building codes and structural design standards

  • Infrastructure planning for roads, dams, bridges, and metro systems

  • Urban development and land-use regulation

  • Disaster preparedness and emergency response systems

Accurate zoning ensures that buildings and critical infrastructure are designed to withstand expected seismic forces, thereby reducing loss of life and property during earthquakes.

Proposed Shift in Methodology

The BIS proposal sought to adopt a more advanced scientific approach known as Probabilistic Seismic Hazard Assessment (PSHA).

PSHA differs from traditional models in several ways:

• It uses probability-based simulations to estimate ground motion.

• It considers multiple possible earthquake scenarios rather than relying solely on historical data.

• It provides dynamic estimates of seismic risk over time.

Many developed countries already rely on PSHA to guide their seismic safety standards because it offers a more nuanced and scientifically robust assessment of earthquake hazards.

India’s Current Seismic Zoning System

India currently follows a relatively simple classification system consisting of four seismic zones:

• Zone II – Low seismic risk

• Zone III – Moderate seismic risk

• Zone IV – High seismic risk

• Zone V – Very high seismic risk

The proposed revision would have introduced a new high-risk Zone VI, covering areas with extreme seismic vulnerability.

Regions likely to be included in this category included:

• Parts of Kashmir and the Himalayan belt

• The Kutch region of Gujarat

• Certain parts of the North-Eastern states

These regions lie along tectonically active zones where the Indian plate interacts with the Eurasian plate, making them particularly prone to strong earthquakes.

Concerns Raised Over the Proposal

Despite its scientific merits, the proposed revision triggered widespread concerns.

Rising Construction Costs

Higher seismic classification requires stricter engineering standards.

• Moving up by one seismic zone could increase construction costs by approximately 20%.

• A two-zone increase could raise costs by around 30%.

Such increases would significantly affect large infrastructure projects such as:

• Metro rail systems

• Dams and hydroelectric plants

• Power plants

• High-rise buildings

Impact on Urban Development

Urban planners warned that stricter seismic requirements could slow development in already fragile regions.

• Many Himalayan and North-Eastern areas depend heavily on infrastructure expansion for economic growth.

• Higher construction costs could discourage private investment and urban expansion.

Growth of Informal Housing

India already has a large informal housing sector.

• Nearly 80% of housing is constructed without formal regulatory compliance.

• If building costs rise sharply:

  • Affordable housing may become even harder to build legally.

  • More households may resort to informal construction practices.

Ironically, this could increase disaster vulnerability rather than reduce it.

Climate and Urban Planning Dimensions

The debate around earthquake zoning also intersects with climate and sustainability concerns.

• The construction sector is one of the largest contributors to carbon emissions in India.

• Stronger seismic construction standards often require:

  • More steel

  • More cement

  • Higher material use

Therefore, any zoning reform must carefully balance multiple objectives:

• Disaster resilience

• Infrastructure expansion

• Climate mitigation

• Housing affordability

These goals are interconnected and require integrated policy planning.

The Way Forward

Rather than abandoning reform entirely, experts suggest adopting a more holistic and consultative approach.

Steps include:

• Developing an implementable earthquake zoning framework that combines scientific accuracy with economic feasibility.

• Conducting wider consultations involving:

  • Seismologists

  • Structural engineers

  • Government ministries

  • Urban planners

  • Industry stakeholders

• Integrating seismic safety standards with climate-resilient and sustainable construction practices.

• Strengthening enforcement of building codes, especially in informal and semi-urban settlements.

Such measures would allow India to improve disaster resilience without undermining development priorities.

Conclusion

Updating India’s earthquake zoning framework is essential for improving disaster preparedness in a tectonically active region. However, the challenge lies in designing a system that is not only scientifically robust but also economically and socially feasible. Any reform must strike a careful balance between safety, infrastructure growth, climate goals, and housing affordability. With careful planning and broad stakeholder consultation, India can move toward a seismic risk framework that enhances resilience while remaining practical and inclusive.