DTE talks to ON Bhargava, geology professor at Panjab University, Chandigarh about why roads must be constructed in the Himalayas on the basis of proper professional advice
A photograph of the trace fossil of a giant scorpion. Photo: Prof Erich Draganitis, Vienna University
Down To Earth puts the spotlight on geo-heritage sites in the Himalayan region on the occasion of World Heritage Day on April 18, 2022. These regions are being destroyed due to road construction activities, according to experts.
In a conversation with DTE, ON Bhargava, honorary professor, geology department, Panjab University, Chandigarh, talks about the geo-heritage sites lost to road construction activities, why we need to preserve them and how mindless construction activities might increase the risk of disasters. Edited excerpts:
Rohini Krishnamurthy: Why is road construction threatening geological records in the Himalayas?
ON Bhargava: The Himalayas are a very hot topic. They are the only example in the world where you have a continental-continental collision (collision of Indian and Eurasian plates).
Everyone wants to come here. The first thing they do is study the geological records (sequence of rocks or the geological structure of the study area and fossil records) visible on the roads.
New road constructions and widening efforts are destroying these records. I am not against road building.
In fact, roads can reveal new geological features. But there should be a method. The rate at which the roads are being broadened is a matter of concern.
They are in a hurry to construct roads and are not consulting geologists. In the 1950s, roads were built in Ladakh by the Army with the help of a competent geologist BN Raina. These roads were so good and stable. They also exposed good geological sections.
Now, what’s happening is that they are broadening existing roads and creating havoc.
RK: Could you talk about some of the important geological records lost?
ONB: The Spiti Valley had a rare trace fossil — the impression of a movement of an animal — of a giant scorpion.
It is found only in three places — Antarctica, India (Spiti Valley) and Australia. Indiscriminate road building has destroyed the fossil evidence in India. We cannot see it anymore.
We also lost a 200-million-year-old coral reef — the best exposure in the Spiti Valley. They started building a canal right above it and the material fell on it. I got in touch with the subdivisional magistrate of Spiti and managed to stop it. As soon as he left, the next person continued and you don’t see the reef anymore.
RK: Where are we seeing maximal damage?
ONB: It is on the Kalka-Shimla highway. This section was almost like a textbook to us as students and even foreigners. Through it, we can understand the entire geological history of this part of the Himalayas.
They are trying to broaden the road. When the road is broadened, you cut the slope, making the stabilised slope unstable. And to stop rocks from sliding down, they have constructed a concrete wall, blocking important geological features.
RK: Why are geological records important and why do we need to preserve them?
ONB: The main aim of any geological investigation is to systemically eliminate areas that are of no geological significance. But in due course of time, we have the academic part as well, which ultimately is applied to finding mineral deposits.
In that process, we work out the geological history of the Himalayas. Geologists are like detectives. They collect different bits of information, piece them together like a jigsaw puzzle and create the geological history of that terrain.
Many times, the evidence is not complete. Sometimes, the record may be missing and other times, we miss the evidence or overlook it. No matter how much I try, I cannot see every square inch of an area, I may miss some.
And the level of knowledge in the past was not so good and this affects how we interpret it. Later, when some more information comes out, we want to revisit geological sites.
RK: Could you talk about how road construction activities are increasing the risk of disasters ?
ONB: Every slope has a different property. They need to look at the rock types involved: It could be shale, limestone, or sandstone. Cutting slopes should also consider the inclination of the rocks — where they are dipping steeply inside the hill or outside. In a hurry, authorities have made vertical cuts, making the slope terribly unstable and generating a lot of slides.
By constructing a wall, you are stopping these slides only temporarily. Because once the slope has been disturbed, the forces inside are still working. A time will come when the forces will overcome the strength of the wall and it may destroy the wall. This is likely to happen.
Another thing is that while widening these roads, so much muck is created and is all thrown into the nearby river. This changes the river dynamics. The worst is that in case of heavy rains or cloudbursts, the entire thing gets mobilised and it works as a very strong force and anything downstream gets disturbed. This is what happened in Chamoli.
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