BEIJING — More than a third of China's land is affected by soil erosion, state media said on Tuesday, underlining a threat to the country's ability to provide enough food and water for its 1.3 billion people.

China last year lost more than 1.6 billion tonnes of soil, the equivalent of one centimetre of earth over a 125,000 square kilometre (48,000 sq mile) area, Xinhua news agency said, adding the worst-hit regions were around the Yangtze and Yellow Rivers.

Soil erosion had affected a total of 3.6 million square km of land, accounting for 37 percent of the country's territory, Vice Minister of Water Resources E Jingping was quoted as saying.

Loss of topsoil is reducing China's already limited arable land. The country has 21 percent of the world's population, but only 10 percent of its tillable earth.

Erosion is also fueling desertification in China's north, where the Gobi Desert has grown dramatically over the past decade and crept closer to Beijing, which suffers thick sandstorms almost every spring.

"Most of the lost soil resulted from over-development and unreasonable construction projects," Xinhua said, citing a report from the Water Resources Ministry.

The erosion problem was especially severe in the Danjiangkou region, an area of lakes and reservoirs between the Yangtze and Yellow Rivers that would be tapped by the planned central line of China's massive South-North water diversion project, it said.

Nearly 45 billion cubic metres of water from the Yellow, Yangtze and other central and southern rivers will be sent to the parched north every year when the project, involving three giant canals, is finished in 2050.

WATER CRISIS

The scheme -- projected to cost almost 500 billion yuan ($62 billion), nearly twice the investment in the Three Gorges Dam, the world's biggest hydroelectric project -- is key to China's plans to address its worsening water crisis.

Per-capita water availability in the country is about one quarter of the world average and expected to fall further. More than 300 million Chinese do not have access to drinkable water, while, measured by its economy, China consumes five times more water than the global average, officials said.

Most of the flood-prone south is spared water shortages, but erosion is still a problem.

The upper reaches of the Pearl River, which feeds the booming coastal cities of Guangzhou and Zhuhai in Guangdong province, were the site of some of the most severe erosion in China, Xinhua said in a separate report.

Source: Reuters