Changes of Precipitation Extremes in Chinas Large Cities

Characteristics of precipitation extremes and the differences between the large cities with a population over one million and the surrounding stations with a population below 500 thousand were investigated based on daily precipitation data of 753 stations of China from 1951 to 2005. Results reveal that changes of precipitation extremes at large city stations display similar regional features. Moreover, the large city stations also have their own characteristic of change. More than a half of the large city stations experienced a more obvious change of the extreme precipitation than the surrounding stations. On the whole, if extreme precipitation intensity and frequency at the large city stations were increased, the increasing trends were more obvious than the surrounding stations. Most of such large city stations are in northern China, especially in the south of North China. Different from the decrease trends in North China, mean extreme precipitation intensity at the large city stations in southern North China has increased obviously.