1961—2015年青海省东北部地区气候变化特征分析

Analysis on Characteristics of Climate Change during 1961-2015 in Northeast of Qinghai

利用1961～2015年青海省东北部地区11个气象站月气象数据（气温、降水量），采用M—K检验、累计距平、线性趋势和小波分析等方法，本文研究了该地区55年来的气候变化特征和趋势。结果表明：近55年来青海省东北部地区年均温变化在2．75～5．63℃之间，呈显著上升趋势，气候倾向率为0．40℃／10a，1986年发生了由低温期到高温期的转折，1997～1998年发生了快速增温的突变；四季均温亦呈升高的趋势，其中冬季气温增幅最大，气候倾向率达到0．55℃／10a，秋季气温增幅最小，为0．34℃／10a．年、春季和冬季均温从20世纪60年代开始变暖，夏、秋季均温在60年代到80年代间有一降温过程，从90年代初开始变暖．年降水量变化在307．4～494．6mm之间，降水量呈微弱减少趋势，气候倾向率为-1．64mm／10a，20世纪60、70年代是降水较多的年代，从90年代开始，降水趋于减少．四季降水量的变化趋势不同，夏、秋季降水趋于减少，冬、春季降水趋于增多．年均温变化存在14年、21年和6年的周期；降水量变化的主周期为26年、14年和5年．

The meteorological data collected at 11 stations in northeast of Qinghai are analyzed based on the methods of the liner regression analysis, accumulative anomaly analysis, Mann--Kendall test and Morlet wavelets analysis to get the characteristics and the trend of the climate change in northeast of Qinghai during 1961--2015. Results show that the climate in this region showed a significant warming trend, the annual mean temperature varied between 2.75--5.63℃, and it has increased by 0.40℃/10a in recent 55years,the climates has transited from cold to warm in 1986 and an abrupt change of fast moving has oc- curred in 1997--1998. In addition, all of the seasonal temperature showed increasing trends,and increase of temperature in winter were higher（0.55℃/10a） than in the autumn （0.34℃/10a）. The decade change of annual and seasonal mean temperature also showed obvious increasing trends. The mean temperature of annual, spring and winter has become warmer in 1960s, while summer and autumn has become warmer in 1990s with a temperature--fall period during 1960s--1980s. The annual precipitation in northeast of Qinghai varied between 307.4--494.6mm, and it showed a weak decreasing trend in recent 55 years, and decreased by--1.64mm/10a. The precipitation in 1960s and has decreased 1970s was more than in the other decades and since 1990s. The seasonal precipitation had showed various trends, it had an increasing trend in winter and spring, as it to an decreasing trend in summer and autumn. The annual mean temperature fluctuated significantly with the interval of 14years, 21 years and 6 years, and the annual mean precipitation fluctuated with interval of 26 years, 14 years and 5 years.