China is bracing for a heavy flood season with 71 rivers already exceeding warning levels, the official Xinhua news agency reported on Tuesday, as meteorological authorities warned that global warming is fuelling more extreme weather. Rain in some parts of central and southern China has hit record highs in recent weeks even though overall precipitation is about 10% lower this year compared with last year, according to the Ministry of Water Resources. Water levels on the Yangtze and its tributaries were expected to rise further over the next week, the ministry said, and it warned of major floods throughout the country from June to August. Some monitoring stations are issuing alerts, with the Wuhan city section of the Yangtze river in central China more than two metres higher than the normal at this time of the year as a result of heavy rain upstream. Last summer, rainfall reached its second highest level since 1961, triggering flood alerts on major rivers and lakes and bringing water levels at the giant Three Gorges Dam close to their maximum. For the whole of last year, nationwide precipitation levels stood at nearly 700 millimetres, 10.3% higher than average and up 7.6% from a year earlier, with rainfall doubling in some parts of central and northeast China. Jia Xiaolong, deputy director of the National Meteorological Centre, told reporters at the end of April that global warming had made China increasingly vulnerable to extreme weather, including heatwaves as well as floods. On Sunday, an unexpected onslaught of hail, freezing rain and gales killed 21 runners during an ultramarathon race in the northwestern province of Gansu. read more This month, a tornado hit Wuhan and another hit the eastern coastal province of Jiangsu, killing 12 people and injuring hundreds. read more