Hydrological activities, including hydrological surveying, monitoring and forecasting, are primarily concerned with studying the properties, distribution and circulation of water.

The regulation, which will come into effect on June 1, states that hydrological organizations should report to local governments as soon as they detect changes in water quality that could potentially indicate instances of water pollution.

Moreover, hydrological organizations are now expected to strengthen their monitoring of changes in water flow and quality that could potentially threaten the security of water use.

The State Council regulation also states that hydrological forecasts should only be released to the public by relevant government departments or authorized hydrological organizations -- other organizations and individuals are not allowed to release the information.

Organizations and individuals that flout the new law and conduct hydrological activities without authorization will be fined 50,000 to 100,000 yuan (6,500 to 13,000 U.S. dollars), according to the regulation.

China continues to encourage international cooperation and communication in hydrological activities and believes that the new regulation will help to regulate the quality of foreign involvement in Chinese hydrological activities.

The new law comes after a similar regulation restricting surveying and mapping by foreigners issued in January.

Like the new law concerning hydrological activities, January's regulation, which was brought into effect in March, stated that any foreign organizations and individuals who wish to survey or map the country, must first gain approval from the central government.

The regulation, issued by the Ministry of Land and Resources, also forbids foreigners from conducting land surveys, aerial photography, mapping administrative borders and drawing navigational maps.

What's more, foreigners must be supervised by local authorities, cooperate with a Chinese partner and their activities must not jeopardize national security.

A Ministry spokesperson commented that the number of foreigners conducting surveying and mapping activities in China is on the rise and many field projects have been carried out illegally at a potential risk to national security.