Context:
Updated earthquake-resistant building codes for the Himalayan region have been withdrawn due to cost concerns, despite warnings of underestimated seismic risks.
Key Highlights:
- Government Initiative / Policy Details
- Bureau of Indian Standards (BIS) withdrew revised IS 1893 earthquake safety norms.
- Decision influenced by Cabinet Secretariat concerns over infrastructure costs.
- Scientific Insights
- New framework based on probabilistic seismic hazard assessment (PSHA).
- Proposed introduction of Zone VI (beyond existing Zone V).
- Suggested Peak Ground Acceleration (PGA) range: 0.15–0.75 g.
- Data & Technical Aspects
- Incorporates data from 168 Himalayan monitoring stations.
- Accounts for local soil conditions, unlike current models.
- Concerns / Issues
- Existing codes may underestimate earthquake risks.
- Stricter norms may significantly increase construction costs.
- Trade-off between economic feasibility and disaster resilience.
Relevant Prelims Points:
- IS 1893 Standard:
- Classifies India into Seismic Zones II–V.
- Guides earthquake-resistant construction.
- Peak Ground Acceleration (PGA):
- Measure of ground shaking intensity during earthquakes.
- Seismic Zones:
- Zone II (low risk) to Zone V (high risk – Himalayas).
- Probabilistic Seismic Hazard Assessment (PSHA):
- Uses multiple variables and probabilities to assess risks.
Relevant Mains Points:
- Disaster Management Issues:
- Need for scientific risk assessment in infrastructure planning.
- Increasing vulnerability of Himalayan region (fragile geology).
- Governance Challenges:
- Balancing cost constraints with public safety.
- Need for evidence-based policymaking.
- Environmental & Geographical Concerns:
- Himalayas are tectonically active due to plate convergence.
- Urbanization increases disaster risk exposure.
- Economic Dimension:
- Higher construction costs vs long-term loss reduction.
- Importance of resilient infrastructure investment.
- Way Forward:
- Gradual implementation of stricter safety codes with financial support.
- Promote earthquake-resilient construction technologies.
- Strengthen monitoring systems and early warning mechanisms.
- Integrate scientific data into policy decisions.
UPSC Relevance:
• GS Paper III – Disaster Management & Infrastructure
• GS Paper I – Indian Geography (Himalayan region)