China is experiencing an unusual summer weather pattern with the rainy season being concentrated in a shorter period and featuring much more intense downpours.
But the Huaihe River valley, where much of this year's flooding occurred, was seeing more days of torrential rain, despite the shorter rainy season, because there were fewer clear days between the rain, said a senior Chinese meteorologist.
Jiao Meiyan, deputy director-general of the National Meteorological Center under the China Meteorological Administration, compared the present rainy season with that of 1991, when massive flooding occurred.
"Large rains began to fall in the Huaihe River valley from the middle of May in 1991, followed by alternate rainy and clear periods. This year is different with continuous heavy rainfalls starting late from June 27 with only short intervals," Jiao said.
She said the intensity of rainfalls was also unusual this year along the precipitation zone extending from the Huaihe River valley, the middle and lower reaches of the Yangtze River to the northern part of southwest China's Guizhou Province.
Meteorological monitoring shows the 24-hour precipitation on July 6 and 7 in Zhangjiajie City, of central China's Hunan Province, amounted to over 400 millimeters, double the previous record.
The daily precipitation in Chuxian County of east China's Anhui Province also hit a record high of more than 300 millimeters.
Due to the influence of a monsoon climate, China's rainfall was mainly confined to the precipitation zone, the location of which was determined by subtropical high pressure zones from the west Pacific, Jiao said.
"The seasonal movement of subtropical high pressure makes the precipitation zone move between the Yangtze-Huaihe area and Huaihe-Yellow River area. Floods in summer are usually regional, but not extensive," Jiao added.
Weather forecasts from the Central Meteorological Station show the Yellow River valley and northwestern areas will see increased rainfall from the middle of July, adding to the flood risks in north China.
(Xinhua News Agency July 11, 2003)
