China is launching a massive construction project to control silt that jams up waterways in the Loess Plateau and to help save the fragile eco-system in one of the world's worst eroded areas, officials said on Saturday. 

Addressing a conference on soil erosion at the Loess Plateau, E Jingping, China's vice-minister of water resources, said a special 83 billion yuan (US$10 billion) fund is expected to be set aside for the construction program to control massive silt flows that occur during flooding.

In the process, silt dams - or so-called silt-trappers - are built across gullies to trap silt that erode during heavy downpours from watersheds or through small river systems.

Such dams have proven the most effective means to improve the delicate eco-system there. They also protect agriculture so grain yields can be increased and farmers' incomes rise to help the rural economy on the Loess Plateau along the middle reaches of the Yellow River, Liu Zhen, director of soil and water conservation department in E's ministry told China Daily.

The Loess Plateau covers 640,000 square kilometers in seven provinces and autonomous regions along the middle and lower reaches of the Yellow River. Forty per cent of the plateau includes eroded gullies and ravines where most of the silt is washed down into the Yellow River.

According to a long-term plan outlined by E's ministry, by 2020, a total of 163,000 silt dams are scheduled to be built across tens of thousands of steep gullies and deep ravines on the plateau using the special funds.

Most of the investment, E hopes, would come from specially issued national infrastructure debt with the rest to be raised by local governments and farmers.

"The annual amount of mud and sands held up by these dams will be up to 400 million tons or a quarter of the total to be washed from the Loess Plateau into the middle reaches of the Yellow River," E said. "The mud and sands usually silt up downstream to cause consequent flooding."

By 2010, the first phase of the erosion-control program should be completed, with about 60,000 silt dams expected to be completed, blocking roughly 14 billion tons of sediment, Liu said.

The detained silt can increase 180,000 hectares of arable land for farmers who otherwise would have to work steep gully slopes by terracing.

Farming on steep infertile sloping lands has caused losses of soil and water, thus worsening the area's eco-system. Erosion there has forced nearly 10 million rural people to live under poverty.

"Farmers' incomes will also be increased by planting crops or cash crops like vegetables and fruits on the silted fertile land," Liu said. He added that yields should be up six- to tenfold over that on farming steep slopes.

(China Daily November 10, 2003)