内蒙古地区1960-2016年气温和降水特征及突变

Characteristics and Abrupt Change of Temperature and Precipitation in Inner Mongolia Area Over the Period 1960-2016

利用内蒙古地区1960—2016年45个气象站的逐月气温和降水量数据,通过线性倾向估计、径向基函数插值法、累积距平、滑动t检验、Mann-Kendall法和小波分析,研究了内蒙古气温和降水量的时空变化特征和突变现象。结果表明:内蒙古近57年来气温呈显著上升趋势,明显高于全球年均温增温率,达0.38℃/10 a,且在1987年发生增温突变;四季气温中,春季和冬季均温升高对年均温上升贡献度最大;年均温和季均温年代际变化呈明显的增暖趋势,年均温、季均温在1990—1999年开始变暖;内蒙古年均温和增温率二者分布规律相同,即:东部<中部<西部。内蒙古年降水量呈不显著上升趋势,年降水量倾向率自西向东呈现出增—减—增的趋势,降水量最少的年代为2000—2009年,降水量最多的年代为1990—1999年,降水量增率为0.47 mm/10 a,且在1999年发生由丰水到枯水、2011年发生由枯水到丰水的两次突变;两季降水量中,内蒙古雨季降水量呈减少趋势,非雨季降水量呈增加趋势,且增加量和减少量均为东部>中部>西部。小波分析显示,1960—2016年内蒙古年均温变化以15 a的周期为最强;年降水量变化以11 a的周期为最强。通过以上分析,1960—2016年内蒙古气候正在由暖干化向暖湿化转型。

Based on monthly temperature and precipitation data from 45 meteorological stations in Inner Mongolia from 1960 to 2016, various methods such as Linear Tendency Estimation, Radial Basis Function Interpolation, Cumulative Anomaly, Sliding t-test, Mann-Kendall Method and Wavelet Analysis were used to explore the temporal and spatial variation characteristics related to the abrupt changes of temperature and precipitation in Inner Mongolia over a 57-year period. The results showed that during the 57 year period the temperature in Inner Mongolia had presented the significant upward trend, which was significantly higher than the global average annual temperature increase rate, and reached up to 0.38 Celsius per decade. An abnormal temperature increase occurred in 1987. Of the four seasons, the average temperature rise in spring and winter contributed the most to the annual average temperature rise. The interannual variation of annual average and seasonal average temperature showed a significant warming trend, and the annual and seasonal average temperature began to increase in the period 1990—1999. The average annual temperature and the temperature increase rate in Inner Mongolia followed the same pattern which was the highest in the west, followed by the middle, and the lowest in the east. The annual precipitation showed no significant upward trend in Inner Mongolia. The annual precipitation propensity rate showed the increase-decrease-increase trend from west to east. The periods with the least amount of precipitation were found during the period from 2000 to 2009, and the periods with the most precipitation were observed in the period 1990—1999. The precipitation increase rate was 0.47 mm per decade and there were two mutations. In 1999, precipitation changed from abundant water to lack of water and in 2011, from lack-of-water to abundant water. The precipitation in the rainy season showed the decreasing trend, and the increasing trend in the dry season. The amounts of increase and decrease were the greatest in the east, followed by the middle, and the lowest in the west. Based on the wavelet analysis, the average annual temperature change in Inner Mongolia from 1960 to 2016 was the strongest in the period of 15 years;the annual precipitation change was the strongest in the 11-year cycle. This study draws the conclusion that the climate was transforming from warm-drying to warming-humidification in Inner Mongolia from 1960 to 2016.