59% areas in India vulnerable to moderate to severe earthquakes
Housing and Urban Poverty Alleviation Minister Venkaiah Naidu released a seismic zone map developed by the National Disaster Management Authority and the Building Materials and Technology Promotion Council. The map revealed nearly 59% areas in India are vulnerable to moderate to severe earthquakes; 95% households are vulnerable to different earthquake degrees. People can access the map on their phones within the next three months.
What are seismic zones?
Regions where the rate of seismic activity - type, frequency, and size of earthquakes over a period - remains consistent are divided into seismic zones. The Geological Survey of India released the first seismic zoning maps in 1935; several modifications have been made later. Zone-I is a very low-intensity zone and the most secure one; no area in India is currently classed as Zone-I.
Four seismic zones in India
There are four seismic zones depending on the earthquake vulnerability. Zone-II is a low-intensity zone; earthquakes in this region are of magnitude 6 or less on the Modified Mercalli Intensity Scale. Zone-III and Zone-IV are moderate and severe intensity zones with magnitude 7 and 8 respectively. Zone-V is a very high-intensity zone with high damage risk and a magnitude of 9 or more.
Earthquake Hazard Zoning Maps
According to an official statement, the report - 'Earthquake Hazard Zoning Maps' comprises color-coded maps. These maps contain tehsil level details and also convey the locations of different areas in five different earthquake intensity zones.
Probability of an earthquake
The seismic zoning maps show the probability of an earthquake occurring in an area. Such maps had been developed in the past; the current maps were developed incorporating locations at the district and block levels for the first time. Additional features like data on population and housing, railway lines, highways, expressways, rivers, water bodies, fault lines, etc. are also included in these maps.
Maps useful to the public
The maps would be helpful to the people in knowing how quake-prone their areas are. Venkiah Naidu stated, "These maps would be of significant help to architects, engineers, land use planners, insurance agencies and those involved in disaster mitigation, emergency planning, and management."
Digitization of the seismic zone maps
BMPTC developed the maps with the help of data available with the Geological Survey of India, Survey of India, Meteorological Department and Census of India at the behest of NDMA. Union Minister Venkiah Naidu appreciated the efforts of BMPTC and requested NDMA and BMPTC to ensure digitization of the maps at the earliest. He suggested a mobile application be developed based on these maps.
Indian metros at risk as well
No Indian metropolis has witnessed a serious earthquake, although as early as April 2016, reports indicated that Delhi was in the high-risk seismic zone 4, while Mumbai, Chennai and Kolkata were in zone 3.