Beijing storm highlights risks for China's cities
Source: Xinhua |
July 24, 2012, Tuesday
|
Print Edition
Print Edition
The fierce rainstorm that claimed 37 lives over the weekend in Beijing has raised questions about the capital's ability to cope with flooding.
Many roads in the city were submerged under waist-deep water for hours on Saturday during the downpour, the heaviest the city has seen in 60 years.
The municipal government said as of Sunday night, 25 people had drowned, six killed in house cave-ins, five were electrocuted and one was killed by lightning.
The rain and flooding also caused blackouts and traffic paralysis. As of yesterday, the Beijing-Hong Kong-Macau expressway had still not reopened as part of it remained submerged.
The disaster affected 1.9 million people and caused nearly 10 billion yuan (US$1.6 billion) of damage, while the exact economic loss is still being verified by local governmental departments, according to Beijing flood control and drought relief headquarters.
Urban flooding has been a chronic problem in China. This summer, rainstorms and flooding have wreaked havoc in many cities, including Guangzhou, Chongqing and Shenzhen.
Experts believe the floods are largely the result of urbanization, with vast networks of roads and the elimination of greenbelts decreasing some cities' ability to cope with heavy rain.
Wang Hao, of the China Institute of Water Resources and Hydropower Research, said that more than 80 percent of Beijing's roads were covered in impermeable materials such as concrete and asphalt, which obstructed the infiltration of rainwater.
However, an investigation led by Li Haiyan, a professor at Beijing University of Civil Engineering and Architecture, said that about half of the drainage networks in Beijing were filled with sediment as thick as 10 to 50 percent of the pipes' diameter.
Sheng Minzhi, an engineer at the Hangzhou Planning Bureau, said the mass construction of tall buildings and underground parking lots in some cities had also slowed the rate at which the ground can absorb rainwater.
Wang Yi, an official with Beijing flood control and drought relief headquarters, said that the drainage systems of Beijing's downtown area were largely built to withstand rainfall of 36 to 45 millimeters per hour.
Only a few places, such as the Tian'anmen Square, had a drainage system that could withstand 56mm per hour of rainfall.
Xu Chenghua, an engineer at the Hangzhou Urban Planning Academy, said storm drainage systems in Chinese cities are supposed to be designed in accordance with the Urban Drainage Engineering Planning Regulations approved in 2000.
Wang Zhansheng, an environmental and engineering professor at Tsinghua University, said the flooding would not be so severe if the drainage systems were designed to handle more severe rainfalls, adding that flooding could be avoided if the regulations took population growth, water usage and sewage treatment into consideration.
A central government group responsible for drafting regulations related to urban drainage met on May 18 to discuss urban flooding. A source said new regulations are expected to be launched next year.
However, Wang Hao said that since the lay-out and functional structure of cities were already in place, to renew drainage systems to the level of developed countries would be hugely expensive.
Many roads in the city were submerged under waist-deep water for hours on Saturday during the downpour, the heaviest the city has seen in 60 years.
The municipal government said as of Sunday night, 25 people had drowned, six killed in house cave-ins, five were electrocuted and one was killed by lightning.
The rain and flooding also caused blackouts and traffic paralysis. As of yesterday, the Beijing-Hong Kong-Macau expressway had still not reopened as part of it remained submerged.
The disaster affected 1.9 million people and caused nearly 10 billion yuan (US$1.6 billion) of damage, while the exact economic loss is still being verified by local governmental departments, according to Beijing flood control and drought relief headquarters.
Urban flooding has been a chronic problem in China. This summer, rainstorms and flooding have wreaked havoc in many cities, including Guangzhou, Chongqing and Shenzhen.
Experts believe the floods are largely the result of urbanization, with vast networks of roads and the elimination of greenbelts decreasing some cities' ability to cope with heavy rain.
Wang Hao, of the China Institute of Water Resources and Hydropower Research, said that more than 80 percent of Beijing's roads were covered in impermeable materials such as concrete and asphalt, which obstructed the infiltration of rainwater.
However, an investigation led by Li Haiyan, a professor at Beijing University of Civil Engineering and Architecture, said that about half of the drainage networks in Beijing were filled with sediment as thick as 10 to 50 percent of the pipes' diameter.
Sheng Minzhi, an engineer at the Hangzhou Planning Bureau, said the mass construction of tall buildings and underground parking lots in some cities had also slowed the rate at which the ground can absorb rainwater.
Wang Yi, an official with Beijing flood control and drought relief headquarters, said that the drainage systems of Beijing's downtown area were largely built to withstand rainfall of 36 to 45 millimeters per hour.
Only a few places, such as the Tian'anmen Square, had a drainage system that could withstand 56mm per hour of rainfall.
Xu Chenghua, an engineer at the Hangzhou Urban Planning Academy, said storm drainage systems in Chinese cities are supposed to be designed in accordance with the Urban Drainage Engineering Planning Regulations approved in 2000.
Wang Zhansheng, an environmental and engineering professor at Tsinghua University, said the flooding would not be so severe if the drainage systems were designed to handle more severe rainfalls, adding that flooding could be avoided if the regulations took population growth, water usage and sewage treatment into consideration.
A central government group responsible for drafting regulations related to urban drainage met on May 18 to discuss urban flooding. A source said new regulations are expected to be launched next year.
However, Wang Hao said that since the lay-out and functional structure of cities were already in place, to renew drainage systems to the level of developed countries would be hugely expensive.
- About Us
- |
- Terms of Use
- |
-
RSS - |
- Privacy Policy
- |
- Contact Us
- |
- Shanghai Call Center: 962288
- |
- Tip-off hotline: 52920043
- 沪ICP证：沪ICP备05050403号-1
- |
- 互联网新闻信息服务许可证：31120180004
- |
- 网络视听许可证：0909346
- |
- 广播电视节目制作许可证：沪字第354号
- |
- 增值电信业务经营许可证：沪B2-20120012
Copyright © 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.
