By Gopal Sharma, Sahana Bajracharya and Navesh Chitrakar
TRISHULI, Nepal, Aug 27 (Reuters) - Rescuers searched Himalayan valleys and hillsides on Thursday after a flash flood that killed at least 359 people and left nearly 1,000 missing, as Nepal and China warned of a risk of fresh flooding from water pooling in two lakes.
Both countries said a glacier collapse on Wednesday morning sent a huge torrent of rock, ice, mud and debris cascading through Himalayan mountain river systems, sweeping through villages
and key infrastructure down a route thronged by trekkers and pilgrims that links Kathmandu with Lhasa in Tibet. Of those missing, at least 540 are foreigners.
Authorities in Nepal used helicopters to search for survivors and drop emergency supplies to thousands cut off in towns and valleys, while emergency services recovered dozens of bodies swept down into the plains.
The sheer amount of water and debris stirred up now risks triggering a further disaster.
Nepal's disaster management authority warned that a lake formed by debris blocking the Bhotekoshi River at the flood site was rising and at risk of bursting, while on the other side of the border China said that some 3 million cubic metres of water — the equivalent of about 1,200 Olympic-sized swimming pools — was expected to flow into an already dammed lake over the next three days.
There is a high risk the lake could breach, with peak flow expected around September 1, Chinese state media said, citing the water resources ministry.
"The volume of water is continuing to increase, and so is the risk," Zhu Jinfeng, a researcher at the ministry's hydrology department, told state broadcaster CCTV.
TORRENT TORE THROUGH BORDER CROSSING
Chinese rescuers had yet to reach the worst-hit area on the Chinese side of the border, the Gyirong border crossing, by Thursday evening, state-media reports indicated, as crews worked to clear debris from the key access road leading to the area.
The Gyirong border port has a key role in China's Belt and Road network linking the country to South Asia, with logistics zones and parking lots built there in the past decade.
Dramatic footage on Wednesday showed enormous torrents of muddy water and debris tearing through structures in the border crossing area within seconds and engulfing people trying to flee.
All the buildings in the border-crossing complex, including the border gate, a stately building bearing China's national emblem and housing customs and immigration agencies, were destroyed by the mudslide, footage filmed from a military helicopter surveying the area and broadcast on state television showed.
The entire compound was reduced to an unrecognisable mass of destruction, caked in thick, muddy debris and almost devoid of any sign of civilization, the footage showed.
The tally of missing in Tibet's Gyirong County was 558, Chinese state broadcaster CCTV said on Thursday, including 260 foreign nationals. China said the death toll stayed at three.
China's Premier Li Qiang, the country's No. 2 official, arrived at the disaster-stricken site in Gyirong on Thursday afternoon, state-run Xinhua news agency said. The visit suggested Beijing was treating the disaster as a matter of the highest national priority.
'EXPLODED LIKE A BOMB'
In Nepal, the Red Cross said that entire villages had been destroyed and impassable roads and bridges had left communities cut off. The full scale of the disaster remains unclear, it added.
Nepal's Home Minister Sudhan Gurung said the focus remained on finding survivors. Rescue teams located 100 missing Indian visitors, mostly pilgrims, and 25 Chinese workers in the worst-hit region around Trishuli.
The flood "came in suddenly and exploded like a bomb," said survivor Janak Bahadur in Nepal's Devighat on Thursday. "The river looked small from a distance but it suddenly started overflowing and swept through."
The missing foreigners in Nepal belonged to more than two dozen countries, including 288 from India, 63 from the United States, 51 from Malaysia, 34 from Australia, 33 from Britain and 25 from Canada.
Ganesh Aryal, the administrator of Chitwan district, said authorities had recovered 103 bodies from the river system in his district, which is about 100 km (62 miles) away in the plains from the worst-hit region of Trishuli.
With local hospitals unable to accommodate all the bodies, district authorities were setting up tents and making arrangements for families to claim their dead relatives, he said.
Nepal's Prime Minister Balendra Shah left by road to assess the flood situation in one of the worst-affected districts of Nuwakot, his office said on social media.
The disaster is a major challenge for Shah's five-month-old government but officials said the country had systems and officials who have experience in handling such tragedies, including the 2015 earthquake that killed nearly 9,000 people.
CLIMATE CHANGE COULD BE A FACTOR
Chinese government geologist Guo Zhaocheng said the ice-avalanche debris flow that caused the mudslide moved at about 50 metres (165 feet) per second, leaving people little time to react, and extended for more than 20 km (12 miles).
Guo said a high-altitude ice avalanche triggered the debris flow, which picked up glacial moraine as it moved down a channel before becoming a mudslide that struck port facilities and areas on both sides of the China-Nepal border.
Early reports had suggested an earthquake in the area could have triggered the glacier's collapse.
But the U.S. Geological Survey said an earthquake with magnitude initially reported as 4.4 was in fact seismic energy generated by the collapse of glacial rock and ice, followed by debris flow.
Scientists cautioned against describing climate change as the sole and immediate trigger for the glacier collapse, but said rising temperatures and melting ice probably played a role.
"Climate change is generating conditions that can destabilise high-mountain rock and ice," said Simon Cox, chief scientist at the Mountains to Sea programme at Earth Sciences New Zealand.
Warming can reduce the support provided by ice, increase meltwater and alter patterns of freezing, thawing and rainfall, making large collapses more likely in some places, Cox said.
DISASTER HIT HINDU PILGRIMS
Many of this week's victims were pilgrims headed to Kailash Mansarovar, a high-altitude site in Tibet revered by Hindus and Buddhists, among others.
Mount Kailash, which Hindus believe to be the home of Lord Shiva and which lies on the banks of Lake Mansarovar, is also held sacred by many.
"There are no human-made things, no human settlement left. Everything is just flat," Sagar Pandey, the chief executive of a Himalayan tourism operator, told Reuters after flying over the zone in a helicopter. "So anyone in the hotel, the restaurant, or the car, I believe that everybody is gone."
Around the world, relatives of those missing were desperate for information about their whereabouts.
Vasanthi Muniandy, whose sister Vennila was part of a Hindu pilgrimage group from Malaysia, said she had last heard from her after Vennila had crossed into Tibet from Nepal.
"I am totally broken. My sister is very important to me," said Vasanthi. "I really want her to come back. I don’t have anyone but her. I just want her to come back home. I want her to be safe."
(Reporting by Gopal Sharma, Sahana Bajracharya, Aftab Ahmed, Saurabh Sharma, Liz Lee, Yukun Zhang, Xiuhao Chen, Shi Bu, Sakshi Dayal, Kanjyik Ghosh, Shilpa Jamkhandikar, Hritam Mukherjee, Ashley Tang and Christine Chen; Writing by Lincoln Feast, YP Rajesh and Michele Kambas; Editing by Saad Sayeed, Hugh Lawson and Rosalba O'Brien)
