Annual and Seasonal Precipitation Variations Trend Analysis in Jinan City from the Year of 1956 to 2007

Based on monthly and annual precipitation data in Jinan City from1956 to 2007, using Mann-Kendall method to analyze the change trend of precipitation in Jinan City. The results show that from 1956 to 2007, Jinan City, the annual precipitation was a significant concussion downward trend. In 1961, there was an inflexion showed rising trend. However, in 1965, there was another inflexion showed a significant reduction in rainfall. In 2003, there was an inflexion showed rising trend again. At the same time, the spring precipitation, autumn precipitation, Summer precipitation and Winter precipitation anomaly from 1956 to 2007 indicated an obvious downward trends, especially in spring, summer and autumn.