BEIJING - China's vast Three Gorges reservoir will see a increasing number of landslides and other geological hazards as the water reaches its maximum level this autumn, a magazine report warned on Monday.

The Three Gorges Dam, the world's largest, aims to tame the mighty River Yangtze and provide cheap, clean energy. Reservoir engineers began withholding outflows last September to push the dam's water level up to 175 meters (574 ft) above sea level.

More slumping and landslides will happen in the next three years, and the higher the water level in the reservoir is, the greater the risks will be, said a report by Caijing magazine (www.caijing.com).

It cited a research paper by the Chongqing Political Consultative Conference, an advisory body in the region.

The Caijing report also said that due to the rising water level in the reservoir, some old landslide fissures are reviving and could become active and move again.

The Three Gorges Dam plan, which cost 254.2 billion yuan ($37.24 billion) and displaced 1.3 million people, was controversial long before construction began in 1994. Critics say rising water levels in the reservoir are eroding already fragile slopes and triggering landslides.

Much of China's land is covered by steep and geologically active mountain ranges, although the Three Gorges area was largely untouched by an earthquake in nearby Sichuan Province that killed 80,000 people in May of 2008.

That earthquake cracked dams in Sichuan, and raised concerns about the safety of many of China's other mega-dam plans.

On Monday, an earthquake measuring 5 on the Richter scale shook southwest Yunnan Province, injuring 28 people and causing more than 1,000 homes to collapse, the official Xinhua News Agency said.

($1=6.826 Yuan)

(Reporting by Huang Yan and Lucy Hornby)