Months of unusually low rainfall has cut the flow of China's biggest river, stalling the movement of freight on a key reach of the Yangtze.

According to the China Daily website, closure to shipping is being undertaken to prevent the grounding of ships, owing to low water levels.

Wikipedia Commons image shows location of Yangtze River. Officials responsible for the waterway were reported as stating that the river was closed between Wuhan and Yueyang, a distance of about 115 miles.

Weather data accessed by shows that rainfall across a vast area drained by the Yangtze has been only one-half to two-thirds of normal since last October. Since the start of March, many of these same areas have had only one-third to one-half of normal rainfall.

At Wuhan, in central China's Hubei province, rainfall since the first of October has been only 47 percent of normal. Since the start of March, only 33 percent of normal rain has fallen.

The low rainfall coincided with the yearly dry season, resulting in even less runoff than usual into the streams and rivers feeding the Yangtze.

Impact of the low rainfall has not been confined to river shipping. According to the China Daily, much of central, northern and southwestern China has suffered crop losses and water shortages, affecting millions of people.

Story by Jim Andrews, Senior Meteorologist