摘要
全球气候变化背景下,极端气候事件发生的频率逐年增大,由此引发的气象灾害事件也随之增加。鉴此,本文利用祁连山讨赖河流域1957—2012年的气象观测资料,对该流域23个极端气候指数的时空变化特征做了研究。结果表明:(1)极端气温升高趋势明显,夜间和白天极端低温日数显著减少,极端气温昼指数显著增大;气温日较差变化幅度很小,霜冻日数显著减少,生长季长度明显加长,冰冻日数2000年后增加;夜指数增大幅度大于昼指数,秋、冬季极端气温升高幅度大于春、夏季。(2)极端降水指数增大趋势明显,雨日降水总量、连续五日降水总量和中雨天数均展现出增大态势,反映出连续降水事件的增加;极端降水量事件增大显著,但雨日降水强度变化不大;除最多连续无降水日数外,极端降水日数指数展现出增大趋势;降水日数夏、秋季节分配趋向均匀化;降水量的增加主要是单次降水时间持续加长和中雨日数增加的贡献;高海拔区极端降水事件发生的频次较大。
Under the background of global change,the frequency of extreme climate events and damage of meteorological disasters are increasing.Based on the data of temperature and precipitation in the Taolaihe River Basin from1957 to 2012,the extreme climate indices were employed to analyze the climatic changing trend and spatial differences.Results indicated that extreme temperature revealed statistically significant increases in the temperature of the warmest and coldest nights.The regionally averaged occurrence of extreme cold days and nights has significantly decreased with the increasing of growing season length.Decreases of the diurnal temperature range and the number of frost days were statistically significant,but a decreasing trend of ice days was not significant and increased after 2000.The greater increasing trend mainly occurred in higher altitudes in autumn and winter.It is also larger for regional trends for night index than in day index.There was also a statistically increase trend for precipitation extremes.At the same time,there is a significant increase in consecutive wet days,number of heavy precipitation days and maximum annual amount for 5-day precipitation and the rain day precipitation,but it not showed the significant increase for the regionally averaged daily rainfall intensity.The distribution of the number of rainy days in summer and autumn is more uniform,and the increasing precipitation mainly contributed by the increase of moderate-rain days and the lengthening of rainfall time for single precipitation event.Extreme precipitation events mainly also occured at high altitude areas in study region.
出处
《中国沙漠》
CSCD
北大核心
2014年第3期814-826,共13页
Journal of Desert Research
基金
陕西省"百人计划"项目
陕西师范大学中央高校基本科研业务费专项资金项目(GK201101002)
中国科学院重点部署项目(KZZD-EW-04-05)
中国博士后科学基金项目(2013T60899)资助
关键词
讨赖河
极端气候
气候变化
Taolaihe River Basin
climate extremes
climate change
