Geologist explains why Uttarakhand tragedy was man-made
Amit Bhattacharya, TNN Jun 26, 2013
NEW DELHI: A day after Uttarakhand chief minister Vijay Bahuguna dismissed as "childish" suggestions that the flash floods in the state were man-made, one of the most respected Himalayan geologists in the country voiced a different view. Padma Shri awardee KS Valdiya told TOI that while "heavy rain and cloudbursts were natural, the tragedy that followed was entirely man-made".
Valdiya, an honorary professor at Bangalore's Jawaharlal Nehru Centre for Advanced Scientific Research, said the heavy loss of life and property in the deluge was a result of "criminal oversight" over the decades of the state's geological features and water channels by various authorities.
"These features are well-mapped and documented. But engineers and builders choose to overlook them," said Valdiya, who comes from the state and has been studying the region for close to 50 years.
The geologist identified four major ways in which constructions flouted scientific norms. First, he said, the seismic faultlines of this earthquake-prone state were not kept in mind while building roads.
"These tectonic faultlines, which are active and see back-and-forth movements, have been cut in many places by roads. More dangerously, roads are built along the faultlines at many places. As a result, tiny seismic movements in the faultlines weaken the rocks at the base of the roads, making these stretches susceptible to cave-ins and slides," Valdiya said.
The second area of rampant neglect, the expert pointed out, was drainage. "I have never seen road engineers provisioning for draining out all rainwater that can possibly enter the stretch. Where one to two metre bridges are required, they build small culverts. At places where drains have been provided for, these are usually filled with debris."
Buildings have been constructed over old drains and streams, blocking the natural pathways of rainwater, he said. "One of the reasons for the devastation at Kedarnath was that people had constructed houses on the west stream of the Mandakini river that had been dry for decades. When the river returned to its old course following the deluge, these constructions were washed away," he added.
Valdiya said another type of transgression, similar to the previous one, was construction taking place on river flood ways. A flood way is the area covered by the river at the time of its biggest flooding in the past 100 years.
"In places along Alakananda/Ganga such as Karnaprayag and Rishikesh, constructions have taken place on the lower terraces which are part of the flood way. Sooner or later, water would get to these places," the expert said.
Lastly, Valdiya said roads have been built over the debris of previous landslides because it's costlier to build paths higher up on the hills where the rock is firmer.
"Sadly, the department geologists are often no more than rubber stamps, okaying everything the engineers say. Independent geologists are never consulted," he said.
Valdiya has written extensively on ways to avoid landslides in Uttarakhand. "But scientific engineering has very low priority in the state," he lamented. Unfortunately, the state pays with human lives and huge property losses because authorities do not pay attention to basic scientific principles.
NEW DELHI: A day after Uttarakhand chief minister Vijay Bahuguna dismissed as "childish" suggestions that the flash floods in the state were man-made, one of the most respected Himalayan geologists in the country voiced a different view. Padma Shri awardee KS Valdiya told TOI that while "heavy rain and cloudbursts were natural, the tragedy that followed was entirely man-made".
Valdiya, an honorary professor at Bangalore's Jawaharlal Nehru Centre for Advanced Scientific Research, said the heavy loss of life and property in the deluge was a result of "criminal oversight" over the decades of the state's geological features and water channels by various authorities.
"These features are well-mapped and documented. But engineers and builders choose to overlook them," said Valdiya, who comes from the state and has been studying the region for close to 50 years.
The geologist identified four major ways in which constructions flouted scientific norms. First, he said, the seismic faultlines of this earthquake-prone state were not kept in mind while building roads.
"These tectonic faultlines, which are active and see back-and-forth movements, have been cut in many places by roads. More dangerously, roads are built along the faultlines at many places. As a result, tiny seismic movements in the faultlines weaken the rocks at the base of the roads, making these stretches susceptible to cave-ins and slides," Valdiya said.
The second area of rampant neglect, the expert pointed out, was drainage. "I have never seen road engineers provisioning for draining out all rainwater that can possibly enter the stretch. Where one to two metre bridges are required, they build small culverts. At places where drains have been provided for, these are usually filled with debris."
Buildings have been constructed over old drains and streams, blocking the natural pathways of rainwater, he said. "One of the reasons for the devastation at Kedarnath was that people had constructed houses on the west stream of the Mandakini river that had been dry for decades. When the river returned to its old course following the deluge, these constructions were washed away," he added.
Valdiya said another type of transgression, similar to the previous one, was construction taking place on river flood ways. A flood way is the area covered by the river at the time of its biggest flooding in the past 100 years.
"In places along Alakananda/Ganga such as Karnaprayag and Rishikesh, constructions have taken place on the lower terraces which are part of the flood way. Sooner or later, water would get to these places," the expert said.
Lastly, Valdiya said roads have been built over the debris of previous landslides because it's costlier to build paths higher up on the hills where the rock is firmer.
"Sadly, the department geologists are often no more than rubber stamps, okaying everything the engineers say. Independent geologists are never consulted," he said.
Valdiya has written extensively on ways to avoid landslides in Uttarakhand. "But scientific engineering has very low priority in the state," he lamented. Unfortunately, the state pays with human lives and huge property losses because authorities do not pay attention to basic scientific principles.
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