A wide-spread threat of land subsidence has been found on the North China Plain, the Guangzhou Daily reported Monday quoting a report of China Central Television.

In 2009, in Cangzhou, a city of North China's Hebei province, a three-story building housing the gynaecology and obstetrics department of the city's People's Hospital was demolished after severe subsidence caused it to sink one story into the ground,, resulting in what was originally the first floor being underground.

This event was a symptom of a greater problem relating to land stability in the city. Wu Ai'min, an official with China Geological Environmental Monitoring Institute, said Cangzhou has sunk by 2.4 meters since 1970s.

Along with Cangzhou, other areas in the North China Plain, such as Beijing, Tianjin are under threat of land subsidence caused by the overexploitation of ground water.

Between 75% and 80% of the water supply in the North China Plain comes from groundwater, said Wu Ai'ming, adding that it will take the natural circulation system more than 10,000 years to replenish the area's 100 billion cubic meters of overexploited groundwater.

Wu also warned that if the land subsidence continues worsening, it may even threaten the safety of the Beijing-Shanghai High-Speed Railway and the South-North Water Diversion Project.