How to contain Himalayan tsunamis

The Himalaya has one of the most fragile topographies among mountain ranges of the world on account of being the youngest. Even though its phase of major upheavals has ended, the Himalayan mountains are still rising. The Indian plate is continuously pushing north about 2 cm every year, and so the Himalaya is rising about 5 mm a year. This means the Himalaya is still geologically active and structurally unstable. What does this mean in terms of predicting disasters in the area? In this series of interviews, Jyotsna Singh talks to experts on the way forward

 
By Jyotsna Singh
Published: Monday 17 August 2015

K S Valdiya K S Valdiya
Honorary professor of geodynamics,
Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR),
Bengaluru

Why is the Himalaya so prone to disasters?

There are many faults in the range. There are four major faults in the Himalaya, including the Himalayan Frontal Fault and the Trans Himadri Fault. Multiple faults have developed parallel to these four. This branching and sub-branching means that this is clearly a zone of faults. The movement of thousands of years means that all rock formations are broken and crushed. Water penetrates deep into the interior and sabotages the rocks from the inside. It washes away the base of the rocks. Thus the number of landslides is high in the region. Landslides and earthquakes will continue to happen in the region because of the movement of the plates in the Himalaya.

What can we do to avoid disasters in the area?

Any human tampering—building roads, constructing hotels on banks and so on—is bound to harm the already fragile landscape. Making and executing laws regarding human activity keeping this factor in mind is the only way to avoid a disaster like the one in Uttarakhand.

Gopal Singh Rawat Gopal Singh Rawat
Senior scientist, International Centre for Integrated Mountain Development (ICIMOD),
Kathmandu,
Nepal

Why is the Himalayan region so vulnerable to disasters?

A phenomenon called the glacial lake outburst flood (GLOF) is responsible for this. Tragedies like the one we witnessed at Kedarnath will continue to happen if planning is not looked at properly. The Kedarnath valley is situated right under the glacial lake at Gandhi Sarovar or Chorabari Lake. It had a huge collection of rubble and moraine. Due to the heavy downpour, it is possible the lake burst out and water flowed into the valley, taking all the sediment with it, thereby making it deadlier. The placement of Gangotri glacial lake – near Gomukh and Gangotri town – is exactly the same. In the event of similar rains the town may face a Kedarnath-like fate. At Gangotri the destruction by the recent floods has largely happened in the lower region. GLOF is a relatively new phenomenon in the Himalaya. It is happening due to global warming which is leading to melting glaciers. This means more and more glacial lakes will be formed in the coming times, leading to potential disasters.

What can be done to avoid the destruction by GLOF?

As a long-term solution, working towards reducing global warming is the first step. Also, the construction of houses should be proper. Old bridges constructed 50-60 years ago have remained intact for a long time. They were built on hard rock. The new ones are unplanned and constructed on fragile ground. They get washed away easily. There has to be a cumulative assessment and strategic planning to mitigate the effects of GLOF.

Saumitra MukherjeeSaumitra Mukherjee
Professor (geology and remote sensing),
School of Environmental Sciences,
Jawaharlal Nehru University,
New Delhi


What is the reason for the disaster?

The changing pattern of vegetation and deforestation coupled with the lack of a study of the terrain are at the heart of such massive disasters. The soil is becoming loose in the Himalayan region where human settlements have cut forests and cultivated crops for consumption. On the north-eastern side of the Himalaya, the glaciers are melting while on the western side they are not. This has to be understood. But only glaciers such as Gangotri, which can be approached, are being studied. This leaves gaps in collecting data and understanding deeply the changing pattern of the Himalaya. The apple line in the area or the altitude at which apples are cultivated is also changing. As the environment becomes warmer, there are changes in vegetation too. We need studies for that.

How can we improve predictions?

The Geological Survey of India has immense data but has not interpreted it well enough. The limitation of this data is that it spans over the past 100-150 years. A better understanding would require data of the past many thousand years. By using satellite images and technology like GIS (geographic information systems), data of the past thousands of years can be collected and analysed. The images of rocks and other formations can tell us a lot about their past. This understanding will help know the current and future movements of the area. This research is the future task which needs to be taken seriously.

Indrajit Pal Indrajit Pal
Centre for Disaster Management,
National Institute of Administrative Research (NIAR),
Lal Bahadur Shastri National Academy of Administration,
Mussoorie, Uttarakhand

What is the best way to prepare for disasters like these?

Capacity building of the local community is key to ensuring that such a disaster is mitigated in the future. Last year the same thing happened in the same two districts, Uttarkashi and Rudraprayag, though, to a lesser extent. We cannot control natural occurrences. But disaster preparedness also has an important role to play. The idea is not to stop development, but to have planned development, which does not disturb the ecology. Development; should not be a synonym for monster. For mitigating disasters, Nepal is aggressively working on community-based disaster preparedness. Local communities' preparedness is the best option as the initial response. When all means of communication break down, especially in the mountains where the connectivity is usually through only a couple of roads, a trained force of locals can save people. The army and other forces take time to arrive. Nepal is working towards capacity building of the local populace and Indian authorities, too, need to adopt the approach.

Can these initiatives be replicated in India? Are there any efforts towards these?

We need similar efforts in India. The topography and terrain of Nepal and the Himalayan states in India are similar. In any case, it is good to have a trained local community to deal with disasters as they form the first line of response. At pilgrimage sites, this is even more important. There is no such system in Uttarakhand, thus escalating the impact of the disaster.


Disaster looms large over Joshimath

Seismic vulnerability and risk in the Himalayan township of Mussoorie, Uttarakhand

Rupture propagation direction in major earthquakes along the Himalayan convergence zone

Subscribe to Weekly Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.