CHANGES IN CHINA’S PRECIPITATION IN VARIOUS CATEGORIES DURING 1957～2004

On the basis of 506 stations with complete daily precipitation records during 1957～2004,the trends of China’s annual precipitation totals,annual precipitation frequencies and mean precipitation intensities are studied. Annual precipitation amounts and precipitation frequencies are additionally studied with a focus on different percentiles. The contributions to trends in precipitation amounts attributing to changes in frequencies and intensities for various categories are further analyzed. Regional trends are found in annual precipitation totals,annual precipitation frequencies and mean precipitation intensities. Trends in heavy precipitation amounts are more significant and changes in heavy precipitation primarily cause the variations in precipitation totals. For most of the categories,the variations of precipitation due to the changing of precipitation frequencies are much greater than those resulted from precipitation intensities. That is to say,trends in precipitation are mainly caused by changes in precipitation frequencies.