Hydropower poses a threat to Shanghai water

Space Daily via UPI:  Extensive hydropower development in the upper reaches of China's Yangtze River poses a threat to the future safety of Shanghai's water supply, says a new study.

The report, by Yangtze River Fishery Resources Committee under the Ministry of Agriculture and World Wide Fund for Nature, known as WWF, is based on a scientific expedition by 32 researchers from government agencies and NGOs through five provincial regions carried out in June.

"One of the most direct consequences for Shanghai is the reduction of the total amount of fresh water that flows from the upper reaches," Yong Yi, a project manager at WWF's Shanghai office, was quoted as saying by the Global Times. "This will cause water safety problems for Shanghai, because the coastal city will suffer from seawater intrusion."

As part of China's energy plan, more than 25 hydropower stations are planned along the 1,434-mile long Jinsha River, one of the major headwaters of the Yangtze. The facilities will be about 62 miles apart and together will supply power equivalent to four times the amount of China's massive Three Gorges Dam project, the world's largest power station that has an installed capacity 22,500 megawatts....

A NASA view from space of the Three Gorges Dam

China to flood nature reserve with latest Yangtze dam

Lucy Hornby in Reuters: China's Three Gorges Corp. on Thursday marked the beginning of construction for a dam that will flood the last free-flowing portion of the middle reaches of the Yangtze, the country's longest river.

The 30 billion yuan ($4.75 billion) Xiaonanhai dam is decried by environmentalists because it will flood a nature reserve designed to protect about 40 species of river fish.

Completion of the dam would turn the middle section of the Yangtze into a series of reservoirs, leaving "no space for fish", said environmentalist Ma Jun, who has been active for over two years in trying to prevent the dam.

"This is the last one, the last section in 2,000 kilometers (1,250 miles) along the Yangtze that was left for endangered or local fish species. This would be their last habitat," Ma told Reuters...

The downstream side of the Three Gorges Dam, shot by Christoph Filnkößl, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Yangtze river pollution sparks panic in China

Terra Daily via AFP: A cargo ship spilled acid into China's longest river last week, contaminating tap supplies and sparking a run on bottled water in eastern China, the government and state media said. It is the nation's second water pollution scare in a month, after factories in the southern region of Guangxi contaminated water supplies for millions with toxic cadmium and other waste in January.

The ship, reportedly South Korean, was docked in Zhenjiang city on the Yangtze river last Thursday when it leaked phenol -- an acid used in detergents -- into the water because of a faulty valve, local authorities reported.

Residents started complaining their tap water had a strange smell on Friday, and soon rumours that a capsized ship was polluting the river sparked a run on bottled water in at least two cities in Jiangsu province, the Shanghai Daily said.

One photo carried by the official China Daily newspaper showed a supermarket shelf stripped nearly bare as a customer loaded water bottles into a shopping cart. The water quality had now returned to normal, the government of Zhenjiang, in Jiangsu, said in a statement late Tuesday. A resident in the city of three million told AFP the run on water appeared to have eased on Wednesday....

The Changshou Yangtze River Railroad Bridge in Chongqing municipality, China, shot by John Roberts, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Thawing permafrost reduces runoff into the Yangtze River

Jane Qiu in Nature: Chinese researchers have revealed that the amount of water entering the Yangtze River near its source on the Tibetan plateau has fallen by 15% over the past four decades, despite a 15% increase in glacial melt and increased rainfall over the same period.

Wang Genxu, an ecologist at the Chengdu-based Institute of Mountain Hazards and Environment, part of the Chinese Academy of Sciences (CAS), says that the findings came as a surprise. “It is in contrast to results from the Arctic where global warming has generally caused increased river discharge,” he says.

Wang and his collaborators at the Cold and Arid Regions Environment and Engineering Research Institute (CAREERI) in Lanzhou, also part of the CAS, have just completed a five-year project to document changes in glaciers, snow and permafrost and to assess their impact on water resources in western China.

Ding Yongjiang, CAREERI’s deputy director, notes that by contrast, many other river systems in western China have seen more water input as glacial retreat and rainfall have increased with a warming climate. The runoff into the Tarim River headwaters, for instance, has increased by 13% since 1961, mainly as a result of increased glacial melt, which has risen by 26%. “But the Yangtze headwaters are an exception,” says Ding.

...The researchers found that the depth of the 'active' ground layer — the part that freezes and thaws every year — is crucial for water passage. Runoff increased if the thawing layer was less than 60 centimetres deep, but decreased if the thaw went deeper. The reasons are unclear but the researchers suspect that when more of the permafrost thaws, the thickened active layer may act like a sponge, soaking up water that would otherwise have run off into the river. Alternatively, more water may leak deep into the ground, also reducing surface discharge....

The upper reaches of the Yangzi River bearing north, having just emerged from the worlds deepest gorge in Yunnan (the Tiger Leaping gorge, SW China. Shot by Peter Morgan, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license