Combine traditional and modern methods to quake-proof buildings
One of the most fragile parts of our country when it comes to seismic pressure is the North-east – all of it falls in the most dangerous zone, barring Sikkim, which is a grade lower. Earthquakes take place at irregular intervals (there were two in Assam before the Nepal crusher hit), although the most recent major one was in Sikkim in 2011 and the worst was the huge Assam tremor in 1950. The latter lasted seven minutes when 41 tremors rippled across the earth. On Tuesday, a strong tremor hit parts of India including the North-east.ht view Updated: May 12, 2015 23:00 IST
One of the most fragile parts of our country when it comes to seismic pressure is the North-east – all of it falls in the most dangerous zone, barring Sikkim, which is a grade lower. Earthquakes take place at irregular intervals (there were two in Assam before the Nepal crusher hit), although the most recent major one was in Sikkim in 2011 and the worst was the huge Assam tremor in 1950. The latter lasted seven minutes when 41 tremors rippled across the earth. On Tuesday, a strong tremor hit parts of India including the North-east.
The great explorer Francis Kingdom Ward was in what is today’s Arunachal Pradesh when the quake struck. This is his stunning description, capturing the invincible power of nature: “Dark as it was, we could see the ridges silhouetted against the paler sky, with their fuzzy outline of dancing trees. The noise was terrific, petrifying, and long continued as whole hillsides, studded with pine trees, slid into the valley. These external clatterings quickly drowned the internal rumblings deep within the crust. But the strangest noises of all came at the end of the shock, when five or six consecutive explosions, all exactly alike, following each other at intervals of several seconds, were touched off. These muffled booms … were heard on the plain of Assam 150 miles distant, and in Myitkina (north Burma) 200 miles away”.
That was 65 years back but Assam and the North-east have been expecting the big one for years, if not decades. The crucial question is: Are we prepared at all? I doubt it: Take two scenarios. Earthquakes don’t kill people but buildings do. Guwahati, the largest city of the region, has some 600 schools and 60 hospitals. According to an expert, not less than 80%of these are vulnerable. “The government is sitting on a huge amount of data and is not doing anything about it,” the specialist said, pointing out that in one case, a power line passes directly over a school in the city. In addition, malls, stores, offices and residential buildings have proliferated on wetlands which have been filled up by the building lobby in connivance with officials and politicians – the maximum damage can take place here because of extensive shaking enabled by the soft soil.
In Aizawl, a risk management assessment pointed out that in the event of a quake measuring 7 on the Richter scale hitting the crowded hill town, almost 13,000 buildings would collapse, 1,000 landslides would be triggered and 25,000 persons would die apart from major damage to utilities and infrastructure. In Aizawl, some buildings have 10 floors, without earthquake-resistant features and located on landslide-prone slopes.
I have suggested elsewhere that the key lies in combining traditional technology with elements of modern building technology, each strengthening the other. Thus most houses of bamboo or wood and walls of plaster and roofs of tin – the ‘Assam type houses’ – are excellent in terms of safety. Yet, their foundations, one study said, are vulnerable. On the other hand, wall and roof collapses cause high casualties in brick and cement buildings. Thus, the foundations of the Assam-type can be strengthened with cement, making it a key model for safe buildings across the region. Wherever they continue to exist, they remain graceful and safe though not ‘modern’.
They are easy to construct, can be built with local skills and with government funding. They’re green, durable and proven. Owner-driven construction is another key: Using local artisans, masons and contractors, with only funds and inspection by the government, people can build houses that are safe and suit their needs speedily. Another important aspect is retrofitting: This can also be done in phases with proper training to local masons or making changes to buildings such as schools and residences, ensuring they are safe for habitation.
There are three key issues here: One is the acceptance of a building code by governments that emphasises the combination of local and new technologies, ensuring safer living spaces for those using it. It is not the question of going back to the past but it is critical that we live safe: What’s the point of pouring hundreds and thousands of crores of rupees of personal and public funds into fancy buildings which end up killing people. Yet, the building lobby, cement manufacturers and others, with their beneficiaries in politics, civil engineering departments and governments will oppose this tooth and claw. It is a multi-billion rupee business that fuels funds to political parties and the entire system.
Second, there must be a safety audit of all multi-storey buildings in Guwahati, Shillong, Gangtok, Aizawl, Kohima and other state capitals as well as buildings in other large towns. A direction from the National Green Tribunal or the state high courts could be the key. Those that don’t match the building code need to be brought down or retrofitted, where possible.
A third is to transform pedagogy in engineering and architecture, earth sciences and geology. Traditional architecture needs to be embraced, not treated, as it is now, as a sign of ‘poverty’.
Recently, the government showered its benevolence on three North-eastern states. It announced that Rs 10,000 crore would be spent on building “road development projects”, in the region. Of this, not less than Rs 6,000 crore was earmarked for Arunachal Pradesh and another Rs 2,000 crore each for Meghalaya and Nagaland. In addition, the ministry of urban development spoke of the Centre’s plan to develop the existing capitals of the North-east as ‘smart cities’.
Ambitious plans to make such ‘smart’ cities of Shillong, Aizawl and other hill capitals of the North-east, which are infested with buildings, with barely space to breathe, should ensure that these are first ‘safe’ cities. It is stupid to live and work in death traps.
Sanjoy Hazarika is director, Centre for North East Studies and Policy Research in Jamia Milia Islamia
The views expressed are personal