UPSC DAW Mains Answer Writing 22nd July 2025

UPSC DAW Mains Answer Writing 22nd July 2025

Question

Discuss how human interventions in the natural hydrological and energy systems can induce seismic activity. Illustrate with suitable examples from India. (10 marks, 150 words) 

Model Answer

Introduction:  

  • While earthquakes are primarily natural tectonic events, human interventions in hydrological and energy systems have increasingly contributed to induced seismicity. Activities such as groundwater extraction, dam construction, and hydrocarbon exploitation (e.g., fracking) alter subsurface pressures and stress regimes, sometimes triggering earthquakes, particularly in tectonically sensitive zones. According to a 2017 study in Seismological Research Letters, over 700 human-induced earthquakes have been recorded globally in the past 150 years, a number expected to rise with growing resource demand. 

 Human Activities Inducing Seismicity: 

  • Excessive Groundwater Extraction:  

  • Drastic lowering of groundwater levels alters pore pressure and the stress equilibrium in fault zones. 

  • A 2021 study linked shallow tremors in NCR (2003–2012) to groundwater depletion. Seismicity subsided post-2014, correlating with groundwater table stabilization. 

  • Reservoir-Induced Seismicity (RIS): 

  • Sudden or massive water impoundment increases stress on underlying faults, especially in seismically active zones. 

  • The 1967 Koyna Dam earthquake (Magnitude 6.3) killed 180+ people. It is attributed to the loading effect of the Koyna hydroelectric reservoir (Source: Geological Society of India). 

  • In Idukki district, increased tremors have been recorded due to hydrological load changes due to the Mullaperiyar Dam, raising concerns in a Zone III–IV seismic area. 

  • Hydrocarbon Extraction and Fracking: 

  • Fracking and fluid reinjection disturb crustal equilibrium, often inducing tremors. 

  • Urban Infrastructure and Tall Buildings: 

  • Large-scale construction (metro projects, high-rises) alters stress concentrations and subsurface dynamics. 

  • Parts of Gangetic plains, sitting on multiple fault lines, are especially vulnerable to shallow tremors induced by construction vibrations and soil compaction. 

  • Climate Change-Driven Hydrological Stress: 

  • Glacial melt and changing rainfall patterns (e.g., cloudbursts, extreme monsoons) contribute to crustal stress. 

  • Western Ghats (Sahyadri Range): Rainfall-induced stress changes have triggered tremors, as confirmed by studies from IIT Roorkee and IMD. 

 Challenges and Concerns:  

  • Seismic Risk Zones: India has ~59% area prone to earthquakes (NDMA 2021). 

  • Lack of Monitoring Infrastructure: Sparse instrumentation in vulnerable regions. 

  • Unregulated Groundwater Use: India is the largest extractor of groundwater globally (~251 bcm/year; FAO Aquastat). 

  • NITI Aayog’s Composite Water Management Index (CWMI) 2023 warned of potential conflicts and geological impacts. 

 Way Forward:  

Measure 

Details 

National RIS Guidelines 

Formulate protocols on dam water release and loading cycles (modelled on USGS standards). 

Integrated Water Management 

Implement Aquifer Mapping Programme (NAQUIM) to balance recharge-extraction. 

Hydrocarbon Regulation 

Frame environmental safeguards for fracking and fluid injection (align with Shale Gas Policy 2023). 

Seismic Microzonation 

Expand microzonation mapping beyond urban areas - currently limited to ~30 cities (MoES). 

Sustainable Agriculture 

Incentivise crop diversification away from water-intensive crops to reduce groundwater stress (NITI Aayog, 2021). 

 Conclusion:  

  • While not all human interventions directly cause earthquakes, their role in modifying tectonic stress regimes is increasingly evident. With India's growing demand for water and energy, it is imperative to incorporate geo-seismic assessments into infrastructure planning and adopt sustainable resource management practices to mitigate human-induced seismic risks.