New safeguards for irrigation systems 

cctv.com 10-20-2005 15:55

Xinjian is home to the world's largest irrigation system, the Karez. Together with the Great Wall and Beijing-Hangzhou Great Canal, the Karez system is one of ancient China's greatest public work projects. As the life source of Turpan, the hottest place in China, the 2,000-year-old water project has now come under new protection.

In Turpan, in northern Xinjiang, where a dry climate and high temperatures are the norm most months of the year, water is extremely precious. But the Karez system has helped the Turpan culture continue for thousands of years.

In this suburb of Turpan city, villagers are busying consolidating the Karez wells. They have put precast slabs on the vertical wells, so as to maintain the quality of water, and prevent the wells from caving in.

Karez systems are considered a miracle of human ingenuity. They are extremely delicate irrigation systems made up of vertical wells, underground canals, over-ground canals and small reservoirs. The wells are sunk at various points to the north of Turpan to collect ground water from the snow that melts on Tianshan Mountain. Water is collected in the vertical wells, and transported through the underground canals from up high to the oasis in the valley below.

At its peak, the Karez irrigation system exceeded 5 thousand kilometers, and was completely constructed by hand in ancient times.

Li Shuwei, Scholar, said, "The high temperatures result in a lack of rain for the Turpan area. The Karez systems did a great job in reducing evaporation and building water storage."

There are currently over 400 systems in the Turpan area, irrigating the agriculture and feeding cattle.

But this number is much smaller than it was 50 years ago. The old Karez system is in danger of drying out due to over-use of underground water. Scientists have warned that the Karez might disappear in the next 30 years, if action isn't taken to protect them.

To rescue the endangered wells, the local authority has taken steps to restrict the exploitation of underground water, and to protect the wells through modern technology. People hope the old Karez system will continue to irrigate the oasis in dessert, and allow this miracle to live on for generations to come.

Editor:Chen Zhuo  Source:CCTV.com