www射-国产免费一级-欧美福利-亚洲成人福利-成人一区在线观看-亚州成人

CHINA> Regional
Silting in Three Gorges Dam less serious than expected
(Xinhua)
Updated: 2008-08-15 00:00

BEIJING -- The silting problem in China's mega Three Gorges project is much less serious than expected, said a senior dam official here Thursday.

Related readings:
 Three Gorges Dam discharges flood water
 Last displaced township dismantled in Three Gorges area
 Algae infests river near Three Gorges Dam
 Three Gorges reduces 200 m tonnes of CO2 emission

The volume of silt carried downriver to the dam area has been one third of that before the reservoir was impounded in 2003, said Cao Guangjing, vice general manager of the China Three Gorges Project Corporation (CTGPC), at a press conference here Thursday.

"Four major factors contributed to this," he said.

He noted that the environmental protection programs to control erosion and restore forests along the upper reach of the Yangtze River have worked.

Another reason is that sand is being taken out from the river bed to meet the need of large-scale infrastructure development in the upper reach, he said.

A number of new dams along the river's upper reach and main branches also holds up mud and sand, he said. "Several new dams are under construction in the region. We expect the volume of silt will continue to drop."

These new projects are part of the country's energy development. They are not built simply to reduce silting in the Three Gorges Dam, he added.

"In addition, the incidence of heavy rainfall in the region has been low in the past few years," he said.

Scientists and environmentalists worried that sediment would pile up behind the world's largest dam, 2,309 meters long and 185 meters high, threatening its safety and causing the river bed in this stretch of the river to rise.

"Silting is listed by the developers of the Three Gorges Project as one of the major technical problems that they face. A lot of investment has gone into resolving the problem," said Prof. Wang Jun, a Chinese water control specialist with the Yangtze River Water Resources Committee (YRWRC).

The project engineers have adopted a system to reduce silting by "storing water when it is clear but discharging it when it becomes muddy."

They have built 23 deep-set spillways in the Dam to wash silt by huge water flow during the flood season.

A YRWRC report issued last year said that 470 million tonnes of silt were piled in the reservoir between June 2003 and the end of 2006, less than expected.

 

 

主站蜘蛛池模板: 成人久久久久 | 国产v综合v亚洲欧美大另类 | 26uuu影院亚洲欧美综合 | 久久久午夜精品理论片 | 亚洲国产最新在线一区二区 | 亚洲国产精品综合久久网络 | 国产爱啪啪 | 中文日韩字幕 | 日本一区二区在线 | 久久综合精品不卡一区二区 | 91精品自在拍精选久久 | 精品欧美一区二区精品久久 | 久久国产99 | 99re7在线精品免费视频 | 久久精品国产99国产精品免费看 | 国产精品美乳免费看 | 亚洲视频国产视频 | 亚洲成人中文 | 亚洲码在线观看 | 91精品视频免费 | 九七在线视频 | 国产一区视频在线 | 国内自拍第一页 | 亚洲综色| 久久91精品国产91 | 亚洲美女视频网址 | 精品国产精品久久一区免费式 | 成人a在线观看 | 亚洲香蕉久久一区二区 | 国产成人一区二区三区影院免费 | 国产欧美日韩精品第一区 | 大臿蕉香蕉大视频成人 | 91国在线高清视频 | www.av视频在线| 免费一看一级毛片全播放 | 日本不卡免费高清一级视频 | 日本一区二区高清免费不卡 | 99精品在线视频观看 | 亚洲美女色成人综合 | 国产一级特黄全黄毛片 | 国产a一级毛片含羞草传媒 国产a自拍 |