With persistent drought still plaguing China, some regions have been involved in a special fight: grabbing for storm clouds.

With the help of modern technology, such as launching of rockets filled with various substances to "seed" the fluffy haze above the earth, rain has fallen on some parched areas.

But the practice of man-made rain has caused considerable controversy in parched China in recent days, with some areas saying that one area's success with rain has meant taking moisture meant for one area and giving to another.

In central China's Henan Province, persistent drought has hit the cities of Pingdingshan, Zhumadian, Luohe, Xuchang and Zhoukou.

Thanks to the artificial cloud-seeding technology, residents in the five cities finally received some wet stuff last Saturday, but by no means equally.

In Pingdingshan, for instance, there was more than 100 millimeters of rainfall.

Meanwhile in Zhoukou, it simply drizzled, with less than 30 mm of rainfall measured.

Zhou Zhengguo, a meteorological official from Henan Province, praised the various cities for having used modern technology to gather their needed rain.

However, meteorological officials in Zhoukou were soon accusing their counterparts in Pingdingshan of "over-using" available natural resources by intercepting clouds that would have likely drifted to other places, say, like Zhoukou.

"Some places have abused rainwater resources," said a Zhoukou expert who asked not to be named.

"They (Pingdingshan) were still launching rockets to make rain when they already had rain falling," he alleged.

The controversy over who gets access to which clouds has shown that the country should draft rules on how to exploit and utilize resources, said Sun Boyang, an weather legal expert from the Henan Meteorological Bureau.

However, Hu Zhijin, of the Chinese Meteorological Society, said the condition is still not ripe for regulation.

While technology for weather modification has a 60-year history, it is a science in development, Hu said.

It is still difficult for meteorologists to test the effects of weather modification, for example, to know precisely how much rainfall has been caused by artificial rain-making activities, Hu explained.

"The natural changes in the atmosphere are very fast and complex," Hu said. "We are not able to observe the atmosphere everywhere at all times, so the data we get is not complete."

Hu said another two decades of research may be needed in order to draft such rules, if then.

The most effective way to manage rainfall is for government entities to co-ordinate efforts.

China established the National Co-ordination Committee of Weather Modification in 1994, and every level of government has a liaison department.

(China Daily July 14, 2004)