From UPSC perspective, the following things are important :
Prelims level : Earthquakes, India's earthquake prone regions
Mains level : India's policy on Earthquake preparedness
- The destruction caused by earthquakes in Turkey should be alarming for India. Over the last three weeks, tremors have been felt in Himalayan states. Moreover, geologists have warned of a probable massive earthquake in the Himalayan state. In this context the Delhi High Court asked the state government to file a status report and action plan on the structural safety of buildings in Delhi. Nearly 58 per cent of the Indian landmass is vulnerable to earthquakes and the concerns that have been raised by the court need a policy response instead.
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How do earthquakes happen?
- According to the theory of plate tectonics, the Earth’s crust and upper mantle are made of large rigid plates that can move relative to one another.
- Slip on faults near the plate boundaries can result in earthquakes.
- The point inside the Earth where the earthquake rupture starts is called the focus or hypocentre.
- The point directly above it on the surface of the Earth is the epicentre.
What is missing in India’s policy on earthquake preparedness?
- Current policy operates primarily at the scale of structural details: Guided by the National Building Codes, this includes specifying dimensions of the structural members columns, beams, etc. and details of the reinforcements that join these elements together.
- While scientifically sound, this view on earthquake preparedness is myopic:
- It ignores the buildings that were constructed before such codes were published in 1962. Such buildings form a large part of our cities.
- It assumes infallibility in the processes of enforcement, relying only on penalisation and illegalities.
- It treats earthquakes as a problem of individual buildings, as if they exist and behave in complete isolation from their urban context.
What needs to be done?
- Preparedness at Building and City Scale through policy: Earthquake preparedness, therefore, needs to act at the scale of building details as well as that of cities. Moreover, we must think about it in the realm of policy and not just legal enforcement.
- Need for Comprehensive Policy: At the scale of building details, we need to create a system of retrofitting existing structures and enforcing seismic codes with more efficiency. While there has been political talk and piecemeal efforts towards retrofitting, we still lack a comprehensive policy.
A policy should include two measures
- Retrofitting Buildings to Seismic Codes:
- To create a system of tax-based or development rights-based incentives for retrofitting one’s building up to seismic codes.
- Such a system of incentives will enable the growth of an industry around retrofitting and will generate a body of well-trained professionals and competent organisations.
- Improving Seismic Code Enforcement:
- By ensuring better enforcement of seismic codes through a similar model. A step forward in this direction was the National Retrofitting Programme launched in 2014.
- Under the programme, the Reserve Bank of India directed banks to deny loans for any building activity that does not meet the standards of earthquake-resistant design.
Case study: Japan
- Japan has invested heavily in technological measures to mitigate the damage from the frequent earthquakes that it experiences.
- Skyscrapers are built with counterweights and other high-tech provisions to minimise the impact of tremors.
- Small houses are built on flexible foundations and public infrastructure is integrated with automated triggers that cut power, gas, and water lines during earthquakes.
- All of this has been a result of cultivating an industry around earthquake mitigation and fostering expertise.
Criteria for an urban-level policy to generate earthquake vulnerability maps
- The percentage of vulnerable structures in the area;
- The availability of evacuation routes and distances from the nearest open ground;
- Density of the urban fabric;
- Location of nearest relief services and the efficiency with which these services can reach affected sites.
- For example: Flood zone mapping is a good example of such an exercise that has proven to be successful in terms of timely evacuation and efficient implementation.
- Governments and policymakers ought to know better than act in a piecemeal manner. Programmes like the ongoing Urban 20 meetings are an excellent opportunity for international knowledge exchange on earthquake preparedness. The Delhi High Court’s directions must act as a reminder for the inclusion of an earthquake preparedness policy in urban renewal programmes such as the Smart Cities Mission. A policy on earthquake preparedness requires a visionary, radical and transformative approach.