河西走廊57年来气温和降水时空变化特征

The Temporal and Spatial Change of Temperature and Precipitation in Hexi Corridor in Recent 57 Years

采用滑动平均、线性回归等趋势分析方法以及Mann-Kendall、Pettitt和累积距平三种突变检验方法对河西走廊地区1955-2011年的气温和降水两个指标进行研究,从而揭示该地区气候变化的事实及趋势。研究显示河西走廊地区的气温在过去57年呈显著上升趋势,升温率是IPCC第四次报告中近50年变暖率的两倍,达0.27oC/10a,并且在1986年发生增温突变;四季气温中,冬季气温升高对年气温上升贡献最大。河西走廊年降水量在研究时段内呈显著增加趋势,降水增率为3.95mm/10a,但各个流域增加趋势并不显著;雨季降水量呈不显著的增加趋势,其年际变化与年降水量一致,雨季降水增量对年降水量增加贡献率大;河西走廊年降水量未发生突变,雨季降水量在1968年发生增加突变。河西走廊温度升高,降水量增加,总体向暖湿化发展,这种变化对该地区水资源脆弱性的影响需要进一步研究。

In this study, monthly temperature and precipitation time series from 1955 to 2011 of 12 meteorological stations were collected and means of linear regression, moving average, Mann-Kendall test, accumulated variance analysis and Pettitt were used to diagnose the behavior of temperature and precipitation so as to reveal the regional climate change facts and its trends. The results showed that the average annual temperatutre in the Hexi Corridor increased significantly in recent 57 years, and its increasing rate was 0.27 ℃/10a which was twice the level of the IPCC Fourth Assessment Report announced, and its abrupt changes were mainly detected in 1986. The seasonal average temperature in this region had an evident uptrend and the trend was most significant in winter. The annual average precipitation change trend rate was 3.95 mm/10a which had a significant rising trend at statistical significance level, but it was insignificant in its three basins. The rainy season precipitation which had the same fluctuation change as the annual precipitation presented no significant uptrend. There were no consistent abrupt changes observed of the precipitation in this study area, but the rainy season precipitation abrupt changes were mainly observed in 1968. With the increase of temperature and precipitation, warming and wetting is evident in this study area.