关键词: 气候变化, 极端降水事件, 西北地区东部, 面积权重, 异常干旱和湿润

Abstract: In this article, area-averaged total precipitation, extremely heavy 1-day precipitation events with area weighted method have been analyzed for the east of Northwest China(ENWC).The result supports the notion that the climate of the ENWC has been becoming more extreme in recent years.Although there is an absence of a monotonically increasing or decreasing trend, the change of precipitation is extreme, since about 1990 it has become below the 30-year mean.The area where precipitation is severe moisture surplus has been decreased and disappeared after the middle of 1990s.The case as that very severe drought from 1960 to 1962 was rare in last 40 years, which mainly occurred in drought area.Severe drought during 1990s occurred in all area, especially in moisture area.In 1997, it is the most extreme during last 10 years;nearly more than 20% of the area on average is in severe drought, drought events occurred in spring, summer and autumn.Nevertheless, the extremely heavy precipitation events did not decrease on this background.

Key words: climate change, extreme precipitation event, east of the Northwest China, area weight, abnormal drought and abnormal moistness