Explainer | From thunderstorms to heatwaves: can Hong Kong’s infrastructure handle the strain?
- The Post explores how extreme weather is testing the city’s infrastructure with the storm season approaching
Hong Kong’s infrastructure appears to be under strain from inclement weather after electricity supplier CLP attributed the recent power disruptions to “more frequent and intense extreme weather events”.
The government promptly asked the power firm to submit plans to mitigate risks arising from the high frequency of thunderstorm warnings. Public utilities Towngas, the Airport Authority and MTR recently also released updates on their weather resilience measures.
Hong Kong is anticipating a hotter-than-usual summer with the possibility of up to eight typhoons between June and October, according to the observatory’s director Chan Pak-wai, who attributed the trend to climate change.
The Post explores how extreme weather is testing the city’s infrastructure with the storm season approaching.
1. What contributed to CLP’s latest service disruption?
A 400kV overhead power system voltage dip triggered outages in many districts in the early hours of Sunday, affecting areas from Wong Tai Sin in Kowloon to various parts of the New Territories, including Sha Tin, Kwai Chung, Fanling and Yuen Long.
The Fung Chuen Court housing estate in Diamond Hill suffered a power outage for over an hour at about 2am, with some residents at Sha Tin’s Garden Rivera complaining that water and electricity were cut off for as long as seven hours.
Joseph Law Ka-chun, the utility’s managing director, said later in the day that the voltage dip could be linked to unstable weather because the thunderstorm warning was in effect then.
The Hong Kong Observatory recorded 4.7mm of rainfall throughout Sunday. It also logged four cloud-to-ground lightning strikes from midnight to 2am and 101 cloud-to-cloud ones between midnight and 4am.
2. Has extreme weather impacted the city’s power supply?
Law said on Sunday the increase in frequency and intensity of extreme weather, such as thunderstorms, heavy rains and rising temperatures, posed a “growing challenge” to its power supply system.
Sunday’s blackout was CLP Power’s seventh power disruption this year, but Law noted that the number of such incidents in the first half of the year was similar to the same period last year.
Just two weeks earlier, a four-hour outage plunged the Wong Tai Sin residential district into darkness, affecting about 2,250 households and businesses at the height of dinner hours. CLP attributed the incident to the fault in an 11kV cable.
On March 30, an hours-long wildfire in Shap Pat Heung, Yuen Long, affected surrounding pylons and triggered a set of 400kV overhead power lines to malfunction. At least 53 lift entrapment cases were recorded.
3. How are residents and workers affected?
Hong Kong logged the hottest month of April on record. On May 4, a rainstorm flooded the Tseung Kwan O residential district. An open-air car park in the Lohas Park seaside housing complex was seen covered with muddy stormwater.
On June 15, the Observatory issued three amber rainstorm signals in one day, prompting the Hong Kong Tourism Board to cancel its monthly pyrotechnics display. And last week, the city recorded its hottest summer solstice.
In the past two weeks, “amber heat stress at work” warnings were issued eight times, with the authorities reminding outdoor workers to take necessary precautions against hot weather.
Last Friday, one construction worker suffered from heatstroke while working on a scaffolding project in Tai Kok Tsui and needed help to return to the ground.
A study by international environmental group Greenpeace last September found that more than 60 per cent of the construction and sanitation workers polled said they had experienced symptoms of heatstroke when on duty, such as dizziness, difficulty breathing and rapid heartbeat.
4. How is Hong Kong coping?
CLP Power said it would take measures to reduce the impact of extreme weather on its power grids. They included more inspections to look for defects in critical facilities, including cable lines and substation equipment, and ramping up workforce and makeshift generators for emergency power restoration when disruptions happened.
The Drainage Services Department is building more flood storage ponds and storm drains to control run-off during heavy rains.
Towngas said it had upgraded its flood prevention facilities at its gasworks in Tai Po and introduced ultrasonic technology to inspect its pipelines.
MTR also said last month that it was installing sensors at 26 stations prone to flooding, such as Wong Tai Sin, Wan Chai and Tai Wai, by the third quarter of this year.
5. What severe weather events are happening outside Hong Kong?
Heavy rains have recently caused disasters in many places in southern China. In Guangdong’s Meizhou, at least 47 people have died due to flooding and landslides, with 14 other deaths recorded in Hunan and Jiangxi provinces.
Saudi Arabia authorities have said more than 1,300 pilgrims died amid soaring temperatures in the holy city of Mecca, as the mercury topped 50 degrees Celsius.
Swiss meteorological authorities said a “once-in-three-decades” storm hit the Mesolcina valley, with landslides leaving three missing.
