Earthquake Threat in the Indian Subcontinent- India Seismic Zone Map and its Field Implementation

It is well established that 60% of India’s population is estimated to be directly under earthquake threat. And, add some more to it, it will cover the whole South Asian subcontinent. One may like to reiterate that approximately 20% of the present world population lives in the subcontinent, and the region has a 10-15% decadal increase in population. The internet (wikipedia) link elaborately explains composition of these countries. See the image below for the increase in population of India over the last 60 years. The subsequent image shows comparative population increase in the subcontinent.

Figure showing population increase in India (Source: Google Worldbank indicators)

Figure showing population increase in the Indian Subcontinent (Source: Google Worldbank indicators)

This increase in population coupled with concern of quality of structures being built leading to increased risk in these areas is thwarted with a parallel argument; whether things are actually that bad in these growing economies, such as South Asia?

Well, it is easier to immerse oneself in numbers or debate, and therefore, become lost. Or, else one can take note of the red spots in the zoning map with hope. Actually, the inspiration to this post is also the India’s earthquake zoning map until someone unknown re-filled the riskiest zone (Zone V) with red. Image below shows that Zone V is more dangerous than Zone II. Red draws most attention, and zoning can be, for ease of implementation, reflected by the fact that India’s seismic map has four zones now. Note Zone I doesn’t exist anymore in the map. This simplification was done to assist implementation in the vast plural context of India after the unfortunate 2001 Gujarat earthquake. This map is a result of the hard and perseverant intelligent work by the Bureau of Indian Standards along with senior experts such as Dr. Arya, and many other engineers who previously worked and have been working on this overwhelming issue of reducing earthquake vulnerability, or for that matter vulnerability to any natural disasters in the country.

Picture above: Map of India showing earthquake zones of India established by the Indian Standards Institution (BIS)

Source: Google image search. Original source: Bureau of Indian Standards

Or, it can be argued that major factors - such as terrain, political, technological capacities, growth, to name some will continue to challenge the implementation of earthquake risk reduction activities in the subcontinent for the coming years. And in case of India, one can pick these red blocks and see clearly where urgent interventions are required - its North Eastern states, and states of Himachal Pradesh, Uttarakhand, and Bihar. Recent devastations in the subcontinent in Kashmir (2005) and Kutch (2001) are well known. These red spots are the riskiest spots, also known as ‘hot spots’. Perhaps, an independent but interconnected framework may help.

Amidst the so called tough ground realities, a stronger coordination is required to avert this ‘time bomb’. “We are sitting on a time bomb”, is what I recall during a meeting with a senior official at Shimla (Zone IV), a nice mellow hill town and state capital of Himanchal Pradesh; situated in a state that is tweaked red. It was 2004 then.

A Useful Tool

Link to Google’s and World bank’s tool for checking a country’s population of last 50 years.