The Weihe River, the largest tributary of the Yellow River and the main source of water for Shaanxi Province in northwest China is in danger of drying up, according to an environmental investigation carried out by the Shaanxi Provincial Environmental Protection Bureau in August.

With the shortage of water, farmers are now planting medicinal herbs where the river once ran.

The investigation report announced yesterday suggests that the Zhuyuan and Qingyuan rivers, two main sources of the Weihe River, have become seasonal rivers, meaning that supplies have not been renewed for half a year.

According to the report: "At the point where the Weihe River joins the two sources, water flow is now only one cubic meter per second in contrast with at least six cubic meters per second in the 1950s."

Data from a hydrological station in Longxi, a county next to Weiyuan County where the two source rivers are located, indicates that no water flows down the 180-kilometer long drainage path of the Weihe River for at least 180 days a year.

This means that the average water supply for each Longxi resident is only 140 cubic meters per year, just one-ninth of the average in Gansu Province, explained Wang Xinrong, deputy director of the bureau.

As a result, it has been necessary to limit water supplies to Weiyuan's 23,000 residents in some areas, according to Zhang Juchang, an official with the county's urban construction bureau. "The underground water level in the county seat area has dropped by two meters in recent years," he added.

The investigation found that increased human activity and environmental deterioration are to blame for the current situation. Between the 1950s and 80s, there was a rampant felling of trees and grassland was converted into farmland. This severely damaged forests that had previously kept the ecological balance in the Weihe River Valley. The development of industry and a huge increase in population have worsened the situation.

?(China Daily September 8, 2006)