摘要
利用黄土高原地区52个气象站1961—2014年月气温和月降水资料,采用线性趋势法、累积距平法、Mann-Kendall法和Morlet小波分析等方法,对近54年来黄土高原气候变化和突变现象进行了分析。结果表明:1961—2014年黄土高原年平均气温呈上升趋势,线性趋势为0.31℃?10a^(-1)(P<0.01),在1991年前后发生了由低温到高温的突变。四季均温均呈增加趋势,其中冬季增速最大,达0.44℃?10a^(-1)。气温年代际变化呈现明显的变暖趋势,1991年以后变暖加速,其中冬季均温增速最大。年均气温增速较大的地区位于黄土高原北部地区,黄土高原南部地区气温增速较小,变暖速率的空间分布随纬度升高而变大。1961—2014年黄土高原年降水量变化不明显,整体呈波动式下降,线性趋势为-7.51 mm?10a^(-1)(P>0.05);其中1961—1970年属于降水偏多的年代,而1991—2000年属于降水偏少的年代。季节降水量呈现不同变化趋势和强度,其中秋季、夏季和春季降水量呈减少趋势,秋季降水减少速率最大,为-3.56 mm?10a^(-1);而冬季呈弱增加趋势,为0.43 mm?10a^(-1)。年降水量减少速率最大的地区位于黄土高原东南部,而黄土高原西北部降水变化不明显。Morlet小波分析结果表明,黄土高原年平均气温存在4 a和7~9 a变化周期,黄土高原年降水量存在5~7 a和12~14 a变化周期。通过以上分析,近54年黄土高原气候总体呈现暖干化趋势。
The pattern and characteristics of climate changes on the Loess Plateau were analyzed with the methods of the linear regression, cumulative anomaly, Mann-Kendall test and Morlet wavelets analysis based on monthly temperature and monthly precipitation data observed at 52 meteorological stations from 1961 to 2014. The results showed that the climate on the Loess Plateau featured a significant warming trend, and the annual mean temperature has increased by 0.31℃ -10a-1 （P 〈 0.01） from 1961 to 2014, and an abrupt change from low temperature to high temperature occurred in 1991. The four seasonal temperatures all showed increasing trends, especially in winter with the increasing rate of 0.44℃-10a^-1. The decadal change in temperatures also showed increasing trends, and exhibited greater warming rates since 1991, especially for winter temperature. The warming rate was larger on the northern Loess Plateau than that on the southern Loess Plateau, and featured greater warming rate with higher latitude. Theannual precipitation showed a decreasing trend in recent 54 years, and has decreased by -7.51 mm. 10a^-1 （P〉0.05） from 1961 to 2014, and the precipitation in 1960s was higher, while in 1990s was less. The seasonal precipitation showed various trends. The autumn, summer and spring precipitation showed decreasing trends, especially for autumn precipitation by -3.56 mm-10a^-1, while the winter precipitation showed an increasing trend of 0.43 mm-10a^-1. The southeastern Loess Plateau showed greater decreasing trend in precipitation, while the northwestern Loess Plateau showed negligible trend. The climate change interval analysis revealed that the annual mean temperature fluctuated with the intervals of 4 years and 7-9 years, and the annual precipitation fluctuated with intervals of 5-7 years and 12-14 years. Overall, the climate was tended to be wanner and dryer in recent 54 years on the Loess Plateau.
出处
《地球环境学报》
2015年第5期276-282,共7页
Journal of Earth Environment
基金
中国科学院重点部署项目(KZZD-EW-04-01)
中国科学院西部之光西部博士资助项目
关键词
气温
降水
气候变化
黄土高原
temperature
precipitation
climatic change
the Loess Plateau
