The groundwater situation in many parts of China is deteriorating due to excessive exploitation and increasing pollution, a senior hydro-geologist warned yesterday.

More than 79 billion cubic meters of fresh groundwater are tapped annually in northern China, accounting for 51.5 percent of total exploitable groundwater resources, Zhang Zonghu, an academician of the Chinese Academy of Engineering, said at the 34th Congress of the International Association of Hydro-geologists (IAH), adding that in the south, 26.7 billion cubic meters are tapped, accounting for 13.2 percent of exploitable reserves.

Based on developments over the past decade, the groundwater situation will remain stable in the south, where rainfall is ample, but will worsen in the north, Zhang said.

As a result, many areas have suffered from environmental damage such as ground settling and depression, and coastal regions are witnessing salt-water intrusion, as well as desertification in the hinterland, Zhang said, adding that to reverse the situation, China has brought the study of groundwater into its national economic development plan.

Groundwater in most parts of the Pearl and Yangtze river deltas has been contaminated, said Yin Yueping, a researcher with the China Geological Survey (CGS) under the Ministry of Land and Resources (MLR).

Yin, director of the CGS Hydro-geology and Environmental Geology Department, said China's groundwater management model is inadequate, working with a poor supervision system and outdated decontamination methods, adding that China's groundwater management had lagged behind the world for years.

Groundwater is any water found beneath the earth. It exists almost anywhere underground, ranging from subterranean pools down to the spaces between particles of rock and soil or in crevices and cracks of rock.

More than 240 scientists from 56 countries attended the five-day event, which "is an important forum for Chinese researchers to learn groundwater management from other countries," said Yin, who is also the secretary-general of the organizing committee.

Co-sponsored by the MLR and the IAH, the congress will promote the survey, assessment, utilization, protection and management of groundwater in China, and its role in sustainable social economic development, Yin said.

(China Daily October 10, 2006)