Debris flows in the Himalayas are difficult to predict, says Russian geophysicist
The high speed debris flows that occurred on the China Nepal border on 26 August are extremely difficult to predict, said leading Russian geophysicist Sergei Chernomorets, a senior researcher at the Laboratory of Snow Avalanches and Debris Flows at Moscow State University (MSU), in an interview with China Global Television Network (CGTN).
Mountain disasters are a reminder that nature is always one step ahead of our technology. Even the most advanced monitoring systems cannot predict the moment when a glacier breaks off from thousands of metres, carrying rocks, mud and death. The tragedy in Gyirong has once again confirmed that in the mountains, humans remain guests, not masters. And once the collapse has begun, rescuers have only minutes to try to warn those in the path of the disaster. But often those minutes are simply not enough.
Chernomorets explained that high altitude collapses and subsequent flows occur every few years with enormous energy. "Avalanches and landslides occurring in the mountains are characterised by very high speeds and great energy. Such events are not unique. Although rare, they occur once every few years. In the initial stage, when a large mass of ice or rocks falls from a great height, the flow reaches very high speeds. The speeds of 50 metres per second calculated here are quite typical for such cases. So, of course, the destructive force is very great," he said.
Once a collapse begins, it quickly turns into a powerful debris flow capable of sweeping away cities, villages and bridges downstream. According to Chernomorets, authorities usually have only a few minutes to issue a warning after the collapse begins, making evacuation of people in the path of the collapse virtually impossible. "Then such a landslide turns into a debris flow, where there is more water, and accordingly, this debris flow washes away cities, villages and bridges downstream. There are many settlements and structures in the path of the flow. Consequently, many casualties. Roads are blocked. Communication is cut off. Accordingly, the only way to get there is by helicopter or on foot, but it is a fairly long distance. Therefore, of course, it is very difficult to organise rescue operations in such conditions," he added.
Chernomorets stressed that preventing such disasters is almost impossible: "Because it is impossible to install a camera on every glacier and assign someone to analyse what is happening on the glacier. Therefore, when the event has already started, it was of course impossible to warn thousands of people in the valley within minutes."
The disaster occurred on 26 August, when the collapse of a high altitude glacier in Nepal triggered a powerful debris flow that struck the Gyirong port on the China Nepal border in the Tibet Autonomous Region in southwestern China. The disaster claimed more than 1,200 lives and left thousands missing. The Himalayan region is particularly vulnerable to such events due to high seismic activity, erratic climate and glacier melting caused by global warming. The rugged terrain and remoteness of the area make rescue operations extremely difficult.
As CCTV+ reports, the Russian geophysicist's words once again confirm that mountain disasters remain one of the most complex challenges for science and rescue services. Without the possibility of accurate forecasting, the only way to reduce risks is to strengthen infrastructure and early warning systems. But as long as nature remains unpredictable, each new collapse will be a reminder of the fragility of human life in the face of the elements.
