Delhi tempts its fate with earthquakes
Buildings on Yamuna floodplains in the Capital could see such scenes.
Delhi, the Indian capital, was rocked by tremors of an earthquake on Monday that slammed neighbouring Afghanistan and so far has killed 335 people. Six months ago, it was Nepal which had lost 9,000 people. North was earlier in the news in 2013 when a cloudburst killed nearly 6,000 people in Uttarakhand.
It seems Delhi is miraculously avoiding a terrible fate due to the infestation of the Himalayan region with seismic activity. Like the one California region in United States suffered in 1906 which simply removed the city from the map for a few years. Or another mega city, Kobe in Japan which just lasted 20 seconds but caused $200 billion damage and left 7000 dead in 1995. Or Pompeii in Italy which remained under a thick layer of dust and debris for nearly 2000 years—though it was the eruption of volcano Mount Vesuvius in 79 AD and not earthquake that had caused it.
With its un-reinforced buildings, the scale of destruction and devastation is too horrible to visualize in Delhi. Thousands of buildings in Yamuna floodplains which falls in Delhi-Haridwar ridge is particularly vulnerable.
If fires break out, as it usually happens in earthquakes, the Draft Disaster Management Plan for Delhi 2014-15 claims that 10 of the city’s 11 revenue districts are prone to fire and it would be particularly hard for the disabled residents. “Uphaar Cinema” fire could be all too common.
Life outside North India isn’t that safe either. A brief look at the earthquakes which singed India is worth a recount.
India suffered for major earthquakes in a span of 50 years once. In 1897, Assam was hit with one of a magnitude of 8.7 on Richter Scale; Kangra earthquake in 1905 (magnitude 8.6), Bihar-Nepal earthquake of 1934 (magnitude 8.4) and Assam-Tibet earthquake of 1950 (magnitude 8,7) are too distant in memory though.
After independence, India suffered many earthquakes but most were of moderate intensity. In 1956, there was one in Anjar, Gujarat; in 1967 in Koyna (magnitude 6.5) and Kinnaur (magnitude 6.2) in 1975. These earthquakes had a moderate limited impact and didn’t evoke a national response from the Centre.
All of this has changed since late 1980s. Six major earthquakes have struck different parts of India since 1988. Intensity was only acute in Bhuj but the damage to human life and infrastructure was immense. It brought home the lingering fear that Indian state isn’t prepared for disasters, god forbids, if it were to strike the big Indian metropolises. It also was evident that earthquakes were now national phenomenon, not just a North India natural monster.
The frequency of earthquakes in the Deccan Plateau (the Koyna, Latur, Jabalpur and Bhuj earthquakes) shocked the experts as it was believed to be the Stable Continental Region (SCR). Bhuj of course was a massive blow, causing 17,000 deaths and a loss of property worth US$4 billion. It easily was India’s worst natural disaster in the last 50 years. About half of India’s land is said to be susceptible to seismic activity.
Like Bhuj, Latur was also of a rather rural appearance. The earthquake which struck it in 1993 was of a moderate intensity of 6.3 magnitude. Yet it cause large-scale damage. More than 70 villages were completely destroyed. Extensive damage was reported in about 1500 villages of Latur and Osmanabad districts. Approximately 90 percent of the buildings were damaged.
If this could happen in villages, one shudder to think what would happen to a major city like Delhi. Delhi, the national capital of India, lies in zone IV, as are a number of cities of north India—Chandigarh, Meerut and Dehradun (Big cities such as Mumbai and Kolkata are in zone III).
The Vulnerability Atlas of India shows seismic risk for four broad categories of houses:
(a)Houses of unburnt brick and clay, fieldstone are most vulnerable and in first category, some 49.43 percent of house stock.
(b)the second category (35.33 per cent) has houses in ordinary brick buildings, buildings of the large block and prefabricated type, half-timbered structures, and buildings in hewn stones,
(c)the third category (3.63 per cent) has reinforced buildings and well-built wooden structures, and
(d)the fourth residual category (12 per cent) has all the remaining houses made of GI sheets, bamboo, thatch grass or leaves.
India was the first country to publish the Standard Code of Practice IS:4326 on earthquake resistant design and construction of non-engineered buildings, including masonry building as early as 1967. However much of its practice is on paper only.
In the wake of growing urbanisation, the reinforced concrete frame buildings in India, which the Bhuj earthquake bore out, have emerged as the most vulnerable aspect of the built environment. Poor design and substandard concrete are its characteristic.
Building codes are not enforced in India. Only a few big municipal corporations have enacted these by-laws. Little verification and poor control persists. In the public sector buildings though, the IS codes are mandatory. That’s why government structures suffered little damage during the Bhuj earthquake.
Financial resources of people of course limit their option to retrofit their houses. There is inadequate information campaign. Insurance is a good mechanism to risk-transfer issues arising out of earthquakes and catastrophic risks. In India though the property insurance has hardly got off the ground. Low incomes and lack of an insurance culture is the heart of the matter. Only those who take loans against the property as defined by housing finance companies, which makes earthquake protection mandatory, take suitable precautions.
There is an urgent need to have a national seismic mitigation programme, like:
(a)Seismic risk must be assessed based on wider database of geology, surface features, soil and historical background.
(b)A national legislation which puts the certification liability on structural engineers, application of codes on state governments and municipal bodies, and mechanism of updating seismic zones and building codes.
Tremendous pressure on India’s lands and monstrous commercial interests are making the situation a real dire one. Shimla, the capital of Himachal Pradesh, has a large number of multi-storeyed buildings in blatant violation of building by-laws. Same in Guwahati in northeast India.
It’s a catastrophe waiting to happen.
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