By Xinhua
Nanchang (China) : More than 100,000 residents around China’s largest freshwater lake, Poyang Lake, are suffering drinking water shortage as a result of drought induced by climate change. An expert has warned that the condition may blight the area for a further 10 winters.
“The lake now covers less than 50 sq km, down from about 3,000 sq km in summer this year. The water surface was 300 to 500 sq km last winter,” said Tan Guoliang, director of the Hydrological Bureau in east China’s Jiangxi Province.
“My house used to be by the side of the lake. Now I have to go more than a dozen km away to get to the lake water. We have been used to the seasonal variations of the lake, but we have never been badly short of drinking water supply,” Yu Wenchang, a villager living near the lake, said.
Some 1,000 villagers in Yu’s village of Xiayangzui in Changdu County of Jiangxi now live on water from four wells.
“A total of 52 of the 56 wells in the village have dried up, as the lake water retreats. Senior citizens told us that they had never seen the lake reduced so drastically in winter,” Yu said.
Villagers have channelled water from a nearby pond to the dry wells, and they are preparing to dig deeper for water.
Many villagers have abandoned the use of boats since they can walk across the marsh of the exposed lakebed.
Poyang Lake’s winter drought is likely to continue for the next 10 years, according to Jiang Tong, an expert with the Nanjing Institute of Geography and Limnology under the Chinese Academy of Sciences.
He said that the size of the lake depends largely on the rise and fall of the Yangtze River. The lake’s drought is a signal showing the effects of climate change in the Yangtze reaches.
“Both the streamflows into the river and the Yangtze River water to replenish the lake will be insufficient in dry seasons in the future, because of climate change and the exploitation of water resources,” said Jiang, a specialist in seasonal water responses to climate and land changes in Poyang Lake Basin.
Poyang Lake receives water from five rivers and discharges into the Yangtze, China’s longest river. The Yangtze River basin, however, has suffered its most severe drought in half a century.
The lack of rainfall along the upper reaches of the Yangtze reduced water levels in the middle and lower reaches by 1.5 meters on average, the Yangtze River Maritime Administration said earlier.
The hydrological bureau’s monitoring revealed that for the last two weeks the inflow from the five rivers feeding the lake was half of the lake’s outflow to the Yangtze.
Tan, the bureau head said that the river has been contributing water at 500 cubic meters per second to the lake since the beginning of this month, less than half of the average in the same period normally. Meanwhile, water is draining out of the lake into the Yangtze at the rate of 924 cubic meters per second.
Rainfall has been unusually low: the provincial average of only 38 millimetres of rainfall from mid-September to early December is the lowest amount for this period since 1960, according to the Jiangxi provincial meteorological department.
“Jiangxi has received meagre rainfall to replenish the lake,” said Zhu Shuigui, head of the Jiangxi Provincial Headquarters of Flood Control and Drought Relief.
He said that the lake’s water inflow normally rises in April and May after the winter drought, which is followed by a rainy season of several months, when the lake begins to swell.
“The drought might last through the winter, when there is normally no effective rainfall,” said Zhu.
He said that an effective measure to ensure water supply for residents affected by drought was to dig more wells.
“We encourage the people to dig wells by providing 1,500 yuan ($202) in compensation for each well they dig,” said Tan.
The Ministry of Finance has readied 70 million yuan ($9.46 million) to support relief programmes in the worst drought-stricken provinces.
Poyang’s water area of 3,000 sq km was still the largest in China, compared with the 2,360 sq km of the Dongting Lake, the country’s second biggest body of freshwater.