Climatic Properties of Summer Precipitation of the Last 45 Years in Liaoning Province

Using 1961～2005 a summer(Jun.～Aug.) precipitation data over 53 stations of Liaoning province,the temporal and spatial variability features were studied by applying the methods of EOF、trend analysis and so on.The results showed that the summer precipitation distribution exhibits the common features as well as the spatial differences.Summer precipitation was decreasing trend over Liaoning region in the last 45 years.Generally,the period of the change was about 4 to 6 years.Summer precipitation was significant interdecadal variations.Summer precipitation was partial to more in 1960's and less in 1970's,and then more in 1980's and 1990's.Since the 2000's,that of first 5 years had been low in the probability distribution of ensemble average.