URUMQI, March 23 (Xinhua) -- Yasin Nuyos and his co-workers crouch in a tunnel three or four meters underground shifting silt in the dim light of a lamp. Sweat flows freely even though the daytime temperature in early spring still hovers below freezing.

    The team, largely consisting of Uygurs in Turpan, northwest China's Xinjiang Uygur Autonomous Region, are preserving a 2,000-year-old network of more than 600 "karezes", or subterranean irrigation canals, that channels water from the snow-covered Tianshan Mountains to cropland and solve the drinking water shortages in the arid region.

    To their delight, the Chinese government will invest 200 million yuan (some 25 million U.S. dollars) this year to make their dredging job easier.

    The money will equip the team with state-of-the-art technologies and machinery in order to protect and restore more karezes in Turpan and Hami, said Hupur Nurdin, secretary general of the Karez Research Association in Xinjiang, in an exclusive interview with Xinhua.

    "We plan to protect 391 karezes, 276 of which will be reinforced," he said. "We'll also restore 89 karezes that have dried up altogether."

    When the entire project is completed by the end of 2008, the restored system will be able to irrigate 8,600 hectares of land, said Nurdin.

    This is by far the heaviest bout of government spending on rescuing the ancient irrigation system hailed by water conservation experts as a good example of man and nature working in harmony, he added.

    The 600-odd karezes that still exist today promise an annual water supply of 200 million cubic meters, not even a third of the 1950s volume, he said.

    Back then, Xinjiang's underground irrigation system comprise more than 1,000 karezes. Its annual water supply was 680 million cubic meters - enough to water 24,200 hectares of land.

    The locals owe a lot to the karezes that help the arid Turpan Basin find fame as China's leading grower of grapes and sweet melons.

    The network of wells and underground irrigation tunnels extends more than 5,000 kms and are found mainly in Turpan, Hami and Hotan. Dubbed "the subterranean Great Wall", it is one of the three landmark projects left by Chinese forefathers - the other two being the Great Wall and the Grand Canal linking Beijing and Hangzhou.

    Yet experts warn it is a pressing job to restore the ancient project, as the region has been losing at least 20 karezes a year,a result of insufficient groundwater, excessive exploitation and lack of funding.

    In response, the local government of Turpan has set up a water consumers' association in every village which, headed by village officials, dredges and reinforces the karezes to ensure sufficientwater supply.

    Meanwhile, the local government has also educated Ugyur farmersin modern irrigation technologies to reduce the per-hectare water consumption by 4,500 cubic meters a year, an annual cutback of 135million cubic meters at least.

    Water conservation experts in Xinjiang have recently completed an illustrated encyclopedia of the region's karezes, a trilingual version of Chinese Mandarin, Ugyur and English, to detail location,storage capacity and length of each existing karez.

    "This is partly because the centuries-old irrigation network has become a major tourist attraction in Turpan," said Nurdin.

    Last year, the network received more than 200,000 tourist arrivals from across the globe. The local tourism administration said Turpan's tourism income totaled 616 million yuan in 2005, or six percent of the local GDP.

    "My parents say the water in the karezes is not only sweet but has a magic skin-caring effect, too," said a Ugyur waitress at a Xinjiang-style restaurant in downtown Beijing. "I wish I could visit the karezes someday and try it." Enditem