BEIJING - The surface water resource use increased 1.6 times over the past 50 years in China, according to researchers.

Researchers from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences reconstructed the runoff of 37 sub-basins from 12 basins around China from the 1970s to the 2000s and compared their findings to the observed data. This allowed the researchers to chart the development of water scarcity, including the ratio of water use to availability (WTA) and the per capita water availability per decade, according to the research paper published in the journal Hydrology and Earth System Sciences.

The results showed that China has experienced a rapid increase in WTA stress, reaching about 65 percent in northern arid and semi-arid regions of the country from the 1970s to the 2000s.

But the WTA stress has stagnated or decreased in most arid and semi-arid basins with only a 5 percent increase nationwide since the 2000s, compared with a 50 percent increase in the 1980s.

The paper also found that the increase in upstream WTA occurred simultaneously with the decrease in downstream water availability for semi-humid to arid basins.

China has been consistently improving the application of water-saving technology and constructing long-distance water transfer projects to solve the increasing water pressure in the downstream catchments, according to the researchers. Yet there remains a need to consider the balance of water resource allocation between upstream and downstream.

Research tracking China's water scarcity can also provide a reference for global water resources management, said the paper.