Spatial-temporal Evolution of Precipitation in China Loess Plateau

For the purpose of discovering the evolution characteristics of precipitation resource in Loess Plateau under the global climate change circumstances,its spatial-temporal evolution and the information flow during the recent 43 years have been studied by methods of EOF,CEOF and wavelet analysis based on the 43 years precipitation data of 51 meteorological stations over 7 provinces in Loess Plateau.The results showed that the yearly and seasonal precipitation responses to the global climate change differ in different regions in Loess Plateau.The yearly and the autumn precipitation decreased abruptly at about 1985.The yearly variation existed simultaneously the periods of 2~4 years and 11~18 years,but with the former as the predominant.The hinterland of Loess Plateau is the sensitive area of precipitation responding to global change;the spatial evolution information spreads to the east.