The Uttarakhand landslide caused huge loss of lives and property and while, the rescue and rehabilitation efforts are underway, city based CSIR-National Geophysical Research Institute (NGRI) Director V.M. Tiwari calls for mission mode projects to map landslide prone regions especially in glaciers in this exclusive interview:
What could have led to the Uttarakhand disaster & why are we still unable to pinpoint the precise cause?
Based on satellite image analysis, and other observations it appears that bedrock landslide occurred at a higher elevation on the morning of Feb 7. The rock mass of the landslide has fallen on the frozen stream bed. That triggered the mass movement of partially saturated debris flow - sediment, ice, and melted ice/snow and thus water flow was less than flash flood observed during 2013. However, investigations are underway whether this rock slide was triggered by a natural phenomenon such as heavy snowfall or seepage of water in the fractured zone from glacier melts over the time etc.
Could the disaster have been prevented or it is one of those unpredictable natural events?
Yes, but the prediction of exact time and location is not possible with the present state of understanding in the Himalayan region. To prevent any disaster from natural phenomena such as landslides and earthquakes it is necessary to study these processes by launching integrated scientific studies and instrumental observations constantly. It is necessary to undertake 'mission mode' projects for mapping the landslide prone regions, especially in glaciers for understanding such phenomena.
Is it possible to have sensors and modern technological tools to give early warning signals like perhaps, for a tsunami to give some kind of alerts?
Yes, we need to develop early warning systems using modern technological tools. There are some indirect indicators that provide information at far field sites, but need to be devised for the Himalayan region.
Such glaciers or landslides are natural phenomena of tectonic plate shifts/glacier movements/melt or could it be the result of large scale deforestation plus man burrowing through the mountains for building infrastructures like roads, canals or power projects?
It is difficult to pinpoint a reason for the event which occurred recently. Your question addresses a suite of phenomena such as plate tectonics. Yes, if there was no plate collision the Himalayas would not have evolved. If there were no Himalayas we would not have had glaciers. One must pause and understand the Himalayan tectonics is still active since the Indian plate is still colliding with Eurasian plate and the mountains after attaining a certain height the mountain building activity moves to a new place. I agree that a sustainable science based action plan is the need of the hour.
Is studying glacial movement a tough subject and very different from the quake or monitoring of the earth crust?
Each of them has its own challenges and especially terrains like the Himalayas. However, there are also space techniques in conjunction with ground based measurements to study the glacial movement
Is it possible to artificially cause such a landslide to cause large scale destruction?
Yes, you know we do blasting for rock mining but for such a large slide to have occurred in Uttarakhand, it requires bigger energy to move.
How is NGRI assisting the Government in the rehabilitation measures? What is the way forward?
First priority for the event was a rescue operation. Therefore within 48 hours, we undertook heliborne geophysical 3D mapping in the Tapovan project area to identify the aerial extent of possible slush penetration in the tunnels. A report was submitted to the concerned authority. This information would help the authorities to plan for rescue and rehabilitation. Further, using geophysical instruments we are trying to understand the rock slide/snow avalanche phenomena which shall have a direct application for the design of early warning systems.
