西藏自治区气温变化趋势分析

Long-term Trend Analysis for Air Temperature in the Tibetan Region

论文主要利用非参数检验Mann-Kendall方法对西藏自治区近40余年来气温的长期变化趋势进行了分析。结果表明,在空间分布上,西藏地区的平均气温是东部高于西部,东部等值线较密集;最高气温的空间分布与平均气温类似;最低气温在空间上呈现东南部与西北部偏高,中部偏低的分布。非参数检验分析表明:近几十年来平均气温有显著的上升趋势,达到0.24℃/10a,且西部地区的上升幅度大于东部地区;最高气温的变化幅度不大;最低气温有显著的上升趋势。无论是平均气温、最高气温还是最低气温,都表现出冬季上升幅度大,春季与夏季升温不明显的趋势。三者之间有很好的相关性。

The Mann-KendaU statistic test is a rank-based, non-parametric method. It has been widely used to estimate the significance of long-term trends in hydro-meteorological time series such as water quality, streamflow, temperature, and precipitation, etc. Temperature is one of the most important climate factors. It is of great importance for the development of economy and agriculture to analyze the long-term trends of temperature. The long-term trend of temperature in Tibetan region was analyzed in this paper. The data used in this paper were observation results from 25 meteorological stations. The Mann-Kendall test was applied to annual and monthly ternperature time series. The results show that the average and minimum temperature exhibited obvious increasing trends during the past 41 years, especially in winter, while the maximum temperature exhibited insignificant trend. The western part of the study area showed more obvious increasing trend than that in the eastern part. The relationships among average, maximum and minimum air temperature were significant.