By using the summer precipitation data of 46 observational stations from 1961 to 2010,the spatial distribution characteristics and temporal variation trend of summer precipitation in Jilin province are analyzed with the Linear Trend Estimation and Rotated Empirical Orthogonal Function (REOF) methods.The results show as follows: (1) the summer precipitation shows a decreasing trend, which hasn't passed the significance test in recent 50 a.An increasing tendency with more frequent alternation between drought and flood has existed in the frequent summer extreme events of drought and flood from early 1980s.The summer rainstorm frequency in the most areas shows a slightly increasing tendency in the context of precipitation anomalies.(2) By objective mathematical method of REOF, summer precipitation in Jilin province is divided into three climatic regions: the northwest plain area, the south-central area and the east mountain area, all of which basically reflect the geographical distribution characteristics of summer precipitation variation.(3) The three climatic regions show different tendency in summer precipitation, that is, a decreasing trend of precipitation leads to increased probability of drought in the northwest plain area, an increasing summer precipitation results in increased probability of flood in the southcentral valley area and less variable summer precipitation in the east mountain area.
国家科技期刊平台
NSTL
万方数据
维普
