保障清洁水源 创造健康世界

3月22日是世界水日，2010年的3月22日是第18届世界水日，同时也是第23届中国水周的第一天。联合国确定的今年世界水日的主题是“保障清洁水源，创造健康世界”,我国纪念世界水日和开展中国水周活动的宣传主题是“严格水资源管理，保障可持续发展”。

Whenever Southwest China has a severe drought, Beijing also suffers from water shortages.

The Yongding River, referred to as Beijing's mother river, was once the biggest reservoir in the city. But because of the city's rapid development and droughts, it has been drying up since the 1970s.

Because of continuous droughts over the past several years, only one of the major five rivers in Beijing still has flowing water. To meet the increasing demand for water in Beijing, the city has been extracting underground water in recent years from pumps 24 meters underground.

But overuse of the underground water supply may result land subsidence and cracks, posing a threat to nearby buildings.

Statistics indicate that 60 percent of the cities in China experience water shortages. Wang Hao from the China Institute of Water Resources and Hydropower Research explains:

"Among China's 667 cities, 420 cities have water shortages, according to research. About 46 percent of these cities lack water resources, 8 percent are threatened by poor quality water, and 26 percent are deficient in water supply engineering."

The United Nations says China is one of 13 countries throughout the world suffering from water scarcity. But what has caused such a severe shortage in China's water supplies?

Experts say insufficient and unevenly distributed water resources as well as the rapid development of the cities with less-developed infrastructures are all to be blamed.

Bi Xioagang, Deputy Director of the Beijing Water Authority, has this to say:

"Especially in the past decade, Beijing has been suffering from droughts. Since 1999, Beijing has had an average annual rainfall of about 480 millimeters, about 20 percent less than the year before 1999. Thus its reserved rainfall water has decreased by 65 percent."

Apart from that, pollution has also brought about water scarcity. Some cities depend highly on underground water, but all of these sources have been polluted.

Another reason for water scarcity is the inefficient use of water resources. Here is Wang Hao again.

"Through the most advanced techniques in the world, two to three kilograms of crops require one cubic meter of water. But in China, one cubic meter of water can only produce less than 1 kilogram of crops. So the efficiency of water use in agriculture must be improved."

Experts say improving water usage is one of the keys to relieving water scarcity. Recycled water is now playing a very important role in some industries.

For China Drive, I am Zhang Wan.