Warning for Hong Kong hikers in wake of black rainstorm signals, record downpours

Hong Kong authorities have urged the public to avoid hiking and stay away from streams and large trees in the coming days, following recent record-breaking downpours that have heightened the risk of landslides and flash floods. The city recorded its second-longest black rainstorm warning on Tuesday, lasting more than 11 hours. Experts warned on Friday that the extent of soil instability was difficult to predict and that a landslide could be as sudden and powerful as an avalanche. The city recently issued four black rainstorm warnings in eight days, the most times the highest-tier alert has been recorded in a single year. On Tuesday, the Observatory recorded a staggering 358.8mm (14.1 inches) of rainfall at its headquarters, the highest daily rainfall in August since records began in 1884, with the torrential rain causing significant damage across the city. On Thursday night, the Highways Department reopened a lane of Bride’s Pool Road, which had collapsed in a severe landslide, after nearly two days of repair work. Some facilities in Plover Cove Country Park and Pat Sin Leng Country Park were temporarily closed. The Agriculture, Fisheries and Conservation Department urged the public on Thursday and Friday to refrain from hiking in the coming days. “For several days after heavy rainfall, the risk of flash floods and landslides is extremely high. Please avoid hiking and staying near mountainsides, streams and rivers for the coming week,” it warned in a social media post on Thursday. “Also, keep away from large trees and waterways. Your safety is the top priority, so even if the weather seems stable again, please hold off on any outdoor excursions for a while.” The Development Bureau also warned in a social media post on Thursday that the public should “stay away from slopes” and avoid hiking even if landslide warnings had been cancelled. Veteran mountaineer Conway Leung Nim-ho said the danger of landslides remained even after the storms. “Even after the rain has stopped, the soil can be saturated with water, and the built-up pressure can cause it to suddenly give way like an avalanche,” said Leung, who is also a committee member of the Hong Kong, China Mountaineering and Climbing Union. “In normal situations, large boulders on a hillside are held securely in place by soil. But after the severe downpour, the soil can be washed away, causing the rocks to lose their support. “This makes them vulnerable to falling, especially with strong winds or more rain.” He added that hikers would have nowhere to hide even if they were alert to the danger, as there could be many boulders rolling down from all directions without cover. Mountain rescue expert Sammy Chun Kwok-leung said there was a high risk of hiking trails being washed away or altered by landslides. “The ground will be very slippery, making it easy to fall or sprain an ankle. If a path is gone, you could easily get lost. Getting lost can lead to other problems, such as hypothermia due to the humid and unstable weather,” Chun said. “If you encounter an emergency on a trail, such as flash floods, you need to immediately move to higher ground and don’t try to cross or walk along low-lying areas. “A warning sign is when river water suddenly turns a muddy colour. For landslides, watch out for yellow mud and rainwater seeping from a hillside wall, as this can be a sign of instability.” Anson Cheng, founder of the Hong Kong Guardians volunteer rescue group, urged hiking enthusiasts to wait a week or two until the weather had stabilised. He emphasised the lingering hazards in rural areas, including delayed landslides and fallen trees that have not been cleared. “Many areas have soil erosion and pose potential risks of landslides that are not immediately visible. It’s quite dangerous to hike now,” he said. Cheng said that while the ground might have dried somewhat in the past two days, it could still be loosened due to the weakened bonds between soil particles and cause danger. He strongly discouraged hiking near streams or engaging in stream trekking activities, saying that there was still underground water that could be discharged and sudden storms that could cause dangerous surges. On September 5, 2020, two men were injured in separate hiking accidents hours after the Observatory cancelled its red and amber rainstorm warnings. One hiker fell up to five metres (16.4 feet) down a section known as “Suicide Cliff” on Fei Ngo Shan. Within 1½ hours, another hiker slipped at Ma Dai Stream in Ma On Shan Country Park. He was helped out of the water by passers-by before being airlifted to a hospital with bruises. Additional reporting by Danny Mok

Warning for Hong Kong hikers in wake of black rainstorm signals, record downpours

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}Authorities, outdoor bodies and rescue groups warn of soil instability on trails following recent deluge

Authorities, outdoor bodies and rescue groups warn of soil instability on trails following recent deluge