Beijing - Experts worry that a destructive vole will find a congenial home in the large expanses of the Dongting Lake bed that have been exposed during the current drought and will infest nearby places.

Dongting Lake in Central China's Hunan province, China's second largest fresh water lake, often plays an important role in mitigating floods along the Yangtze River region. Not so this year.

Since January, between 50 percent and 60 percent less rain has fallen on the region than had on average in previous years. Water in the lake usually stands at its highest point in May, but that high point now isn't likely to come until later in 2011.

Water voles may proliferate in dry parts of the lake bed, according to a report from Xinhua News Agency. And if the water doesn't rise fast in June, which seems likely in the light of current rainfall forecasts, the pests will have enough time to migrate and cause an infestation around the end of next month - harvest time for early season rice and transplantation time for late season rice, Xinhua reported.

Figures collected by meteorological satellites showed the lake encompassed 382 square kilometers at its surface on May 17, a figure far below the 1,649 sq km it had encompassed on May 24 last year and 60 percent lower than the water surface's average area for this time of year, the report quoted Han Qinzhe, a researcher with Hunan Institute of Meteorological Research, as saying.

Rainfall from May 21 to May 24 helped to increase the area of the lake's water surface to 577 sq km on Friday. Also beneficial was water from the Three Gorges Dam, which opened its locks to mitigate the drought.

But the lake's water surface area remained far below what it usually is in wet seasons, when it may be as much as 2800 sq km to 3900 sq km. The drought, meanwhile, has caused severe harm to the lake's wetland ecosystem, Han said.

The exposed parts of the bed are either becoming dry land or grasslands. Ships along the main waterway, which became narrower as the water level decreased, are seen far less often than before, and many fishing boats have been stranded, according to the report.

Similarly, the water volume in the Poyang Lake, the largest freshwater lake in China, has shrunk to 740 million cubic meters - 87 percent fewer cubic meters than has been the average in previous years.

The center of the Jiangxi province lake has become a grassland.

"Normally we would have our dragon boat races in May," said a villager surnamed Qiu, speaking near the lake in Hongwei village. "But now there is no water, only grass."

China Daily

(China Daily 05/30/2011 page5)