The Yellow River will run dry more often, leading to increased water shortages, scientists have warned. A joint study by the Qinghai Geological Survey and China Geological University has blamed worsening environmental conditions and global weather changes for the deteriorating situation. It said water tables in the Qinghai-Tibet region which fed the river were shrinking, Xinhua reported. The region has experienced a decline in rainfall as a result of global climatic changes. The joint report was based on a three-year study of the 5,464km-long river, which runs into the Bohai Sea in eastern Shandong province. The river, which is the mainland's second longest, is known as the cradle of Chinese civilisation and has traditionally provided water to 12 per cent of China's population. One of the report's authors, Zhang Shenqi, told Xinhua that activities such as mining had caused serious soil erosion and desertification. As a result, the area's ecological balance had been damaged, causing hundreds of lakes and streams to dry up. The Yellow River has flooded many times over the centuries. It has also dried up on numerous occasions, but analysts say both the rate and severity of disasters on the river have been increasing in recent years. Since 1985, it has run dry annually and in 1998, it dried up for more than seven months, the longest spell on record. In August, Beijing announced it was preparing a 10 year, 150 billion yuan (HK$141 billion) project to tackle the Yellow River's flooding and environmental problems. As well as building new dams and aqueducts, pollution control and erosion prevention measures would be put in place. Meanwhile, the Yangtze River Water Resources Committee has reported that 59 cities along the river face water shortage problems, with 26 at crisis point, Xinhua said. The committee found that last year, the amount of water available per capita in the Yangtze region dropped to about 2,100 cubic metres, a quarter of the world's average, due to drought. It also said that the Yangtze River was severely polluted. More than 2.2 billion tonnes of industrial and urban waste was dumped into the river last year, four times the level two decades ago, it said.