Chaos in capital a perfect storm
Inaccurate forecasting, poor infrastructure and bad co-ordination were blamed yesterday for the chaotic scenes on Thursday when the capital turned into a big swamp during the heaviest downpour since 2004.
Though road and subway traffic in the city centre had mostly recovered thanks to the overnight repair efforts of thousands of workers, more than 200 flights were still delayed or cancelled yesterday.
Qiao Lin, director of the Beijing Meteorological Bureau, said on its website that on Thursday it recorded 21.5cm of rainfall at a Shijingshan district residential compound in less than two hours, the biggest downpour since a storm in July 2004 that lasted more than four hours and caused similar chaos.
'Such a strong precipitation event is rare,' he said.
But Qiao did not explain why the storm warning issued by the bureau on Thursday was blue, the least severe, with estimated rainfall less than a fourth of that recorded.
An official at the bureau's observation and forecast department declined to comment yesterday.
Wang Yi , director of the capital's municipal flood-control office, told the Beijing Times yesterday that most of the city's drainage system could only handle hourly rainfall of 4.5cm at most. Only a few important locations, such as Tiananmen Square, could take more.
But Thursday's rain reached 12.8cm an hour, causing flooding up to 60cm deep at 20 locations, mostly overpasses on the Third and Fourth Ring Roads in western Beijing, Wang said.
Wang said that the authorities were considering upgrading the drainage infrastructure and doubling its capacity.
'The earliest underground drainage networks in downtown Beijing were built in the Ming dynasty [1368 to 1644] and are still in use nowadays. Drainage construction is the slowest of all urban construction. It is a national problem.'
Professor Lu Jian, an infrastructure expert at the Beijing University of Technology who is also a drainage network-design consultant for the municipal government, said yesterday that Thursday's downpour also revealed poor co-ordination among the different government agencies.
After the chaos in 2004, the municipal government set up an emergency-response task force, equipped with powerful water pumps, to be on standby during flooding emergencies, Lu said.
But Thursday's storm showed that there was little co-ordination between the task force and the weather authorities, he said. The task force was not mobilised and dispatched until the rain began pounding, and most of the force's teams were stuck in traffic jams and could not reach their destinations.
Some private vehicles also occupied the emergency lanes of highways, refusing to let the water-pumping vehicles pass by.
'It is not one person or one department's fault. It is everyone's fault,' Lu said.
Kong Yanhong, deputy director of the China Academy of Urban Planning and Design's Water Centre, said that the rainfall in some of the worst-flooded areas on Thursday was probably the heaviest in a century.
'Beijing's drainage system is not designed to stand against low-probability events,' Kong said, adding that the cost of being able to do so would be prohibitive.
Xu Gang, an engineer at the Beijing Tsinghua Urban Planning and Design Institute, said that most of the mainland's investment in urbanisation was on the surface, resulting in inadequate supporting infrastructure underground.
'It is never too late to learn from Paris, which solved the problem more than a century ago,' Xu said.
At Beijing's Capital International Airport, many domestic passengers were stranded, with 122 flights delayed and 103 cancelled yesterday.
International flights were less affected, with six delays and 11 cancelled, all in Asia, with more than half to or from Hong Kong and Macau.