Desertification in Tibet’s Wetlands Threatens the Yellow River
Desertification in Tibet’s Wetlands Threatens the Yellow River
The “kidneys” of the Tibetan plateau are failing.
The Zoige Wetland National Nature Reserve, which sits on the northeastern fringe of western China’s Qinghai-Tibet plateau, contains the largest alpine peat wetlands in the world. It is also the catchment area for the Yangtze and Yellow Rivers; known as the “kidneys of the plateau,” these wetlands provide at least 30 percent of the water flowing into the upper reaches of the Yellow River.
But they are gradually disappearing. Desertification here is increasing at a rate of more than 10 percent per year. “Of the county’s seventeen villages and towns, ten are suffering from desertification, and more than 70,000 hectares are affected,” said the deputy head of Zoige County Forestry Bureau, Zuo Lin. “The situation is quite critical.”
Water increasingly scarce
Herdsmen on Zoige county’s grasslands are finding it more and more difficult to find water these days, explained Sonam Dorje, a staff member at Zoige Wetland National Nature Reserve. “You used to be able to dig down two or three meters and find water; then later you had to dig seven or eight meters. Now in some places you have to go below 10 meters.” He described how, after many years of studying the area, he has watched the underground water level sharply decline and plants die off, exposing thick layers of sand.
The situation in Maixi township, Xiaman township, and Tangke township is especially serious, said Sonam Dorje. In the hardest hit places, the desertified area doubles in size every year. “Sometimes you have pasture still there in the summer but by winter it has already turned to sand,” he said. “Herders are abandoning more and more areas because they are unsuitable for grazing.”
Zoige has conducted four desertification surveys since 1995. The first found that only 16,000 hectares were desertified. The latest research, carried out in 2009, showed that in the whole of Zoige county, 72,000 hectares were desertified, or 6.76 percent of the county’s total area. Today, the area of grassland in this county which is threatened by desertification has reached 135,000 hectares, with close to 30,000 people affected, that’s about 39 percent of the whole county’s population.
Deputy head of Zoige Wetland National Nature Reserve Li Hua said that Zoige’s genuine wetlands are shrinking—that more and more land is turning to grassland. Currently, just under a third of the wetlands are in their original state; the other two thirds are degraded.
There were originally more than 300 lakes of all sizes in Zoige. Today, more than 200 of them have dried up. Those left are far smaller than they used to be, or have turned into seasonal lakes. Maixi township’s Xingcuo Lake was originally 469 hectares in size; it is now less than 10.
Grazing pressure on the grassland
As one of the country’s “big five” grasslands, Zoige faces a livestock overload. There were 330,000 heads of livestock in Zoige county in 1953, according to local government statistics. By 2011, that number had climbed to 1.2 million.
In the past, the pressure prompted efforts to actively expand the grassland. By digging drainage ditches to turn wetland into grassland, went the logic, locals would have space for more cattle and sheep, ensuring long-term prosperity. In 1964, the year of the “Learn from Dazhai” campaign—Mao Zedong’s call to the people of China to follow the success story of a farming community in Shanxi province—more than 380 kilometers of ditches were dug across one million mu (667 square kilometers) of wetlands in order to drain water into the Yellow River. This has been one of the key drivers of Zoige’s desertification plight.
Zuo Lin explained how peat wetlands form: during winter-time, many herbaceous plants die and rot. The decaying vegetation piles up over a long period of time and, via a complex process, eventually forms peat. It grows thicker and thicker and is like a sponge, which means it can store water. When a wetland degrades, Zuo continued, the first sign is that water levels begin to drop. The wetlands gradually shrink and turn to grassland, losing their ability to store water. Lacking a water source, the grasslands soon turn into desert.
To the east of Zoige is the Yangtze River and to its west is the Yellow River. The western peat wetlands have a water-storage capacity of 5.6 billion cubic meters; add to that the water storage of the lake and grassy marshland and the total water-storage capacity of Zoige’s wetlands is close to 10-billion cubic meters. It is the world’s largest alpine “solid reservoir” and it is known as the Yellow River’s water resource. Zoige plays an irreplaceable role in regulating the climate, protecting soil and water and maintaining biodiversity. The protection of the wetlands is connected with the security of the Yellow River system and the region’s ecological stability.
The piecemeal protection of Zoige’s wetlands began back in the 1960s. Sichuan province, in which Zoige lies, has made efforts to conserve parts of the wetlands through the Wetland Protection Project and the Northwestern Sichuan Desertification Project. By measures including filling in drainage ditches and raising the water levels in lakes, they have restored part of the wetlands.
But overgrazing has challenged these efforts. Sonam Dorje explained that the grasslands are currently divided up between households. That means that, if you want to protect the land, you need to seek the approval of the herders who have usage rights over it. “However, as you start filling in ditches and canals, the wetlands begin to recover, and the grazing area for the herders’ cattle will decrease,” he said. “So it’s very difficult to implement this ditch-filling policy on a large scale. On the whole, we can only fill in a couple of kilometers worth every year.”
Efforts to control the spread of sand are also affected by overgrazing. When herders see grass beginning to grow on a sparse pasture after sand barriers and sand controls have been put in place, they quickly move their sheep and cattle to that area of land. If wire netting is put up to protect it, they just cut the wire, and the animals get in and graze as before.
Sonam Dorje said: “Desertified areas need about three years to recover after being treated according to our experience. But since we are dealing with a vast, but sparsely populated area, they are especially difficult to protect. People often damage the fences, undermining the effectiveness of the protection work.”
The struggle for permanent protection
In Zuo Lin’s opinion, years of conservation work have been unable to prevent the problem of the wetlands being “partially protected but overall deteriorating.”
“Between 2004 and 2007, less than 2,000 hectares of all levels of desertified land were fully restored across the whole of Zoige county, which only accounts for 4.58 percent of all newly desertified land during this period,” he said. Insufficient investment in late-stage protection means some of the restored land ends up facing degradation for the second time, he added.
Gu Haijun, deputy chief of Sichuan Forestry Department’s wetland-protection center has repeatedly said that wetland conservation still lacks long-term, sustainable project support. The other major problem, Gu told China National Radio, is a lack of funds. They need more than one billion yuan (US$158 million) to fill in just 800 kilometers of ditches, he said. But the whole county’s annual fiscal revenue is only 20 million yuan (US$3.2 million). Even just to maintain basic government operations, Zoige looks strapped for cash.
In July, the State Forestry Administration’s Wetland Conservation and Management Centre sent a research group to Zoige’s wetlands. The group concluded that the key to a sustainable future on Zoige’s wetlands is to implement the “West Sichuan and Tibet ecological conservation and construction plan” as soon as possible, adopt comprehensive measures and carry out wetland conservation and desertification control on many different levels and fronts.