新疆开都河-孔雀河流域近59年极端气候事件时空变化特征

Characteristics of spatial and temporal changes of extreme climate events in the Kaidou River-Kongque River Basin in Xinjiang in recent 59 years

基于1961—2019年新疆开都河-孔雀河流域(简称开孔河流域)8个气象站点逐日最高、最低气温和降水量数据,采用一元线性回归法、Mann-Kendall突变检验、反距离权重插值、相关性分析等方法分析了18个极端气候指标的时空变化特征。结果表明,在时间上,开孔河流域大部分地区的极端高温指数呈明显上升趋势,气温日较差(DTR)和极端低温指数以下降趋势为主;各极端降水指数的变化不明显,最多连续无雨日数(CDD)呈显著下降趋势;极端气温的突变时间主要集中在20世纪80年代末至21世纪初,极端降水指数突变年份主要集中在20世纪80年代至90年代初。在空间上,极端气温指数夏日日数(SU25)、热夜日数(TR20)、暖昼日数(TX90p)、热持续指数(WSDI)、冰冻日数(ID0)的气候倾向率呈西北低、东南高的分布特征,冷持续指数(CSDI)、冷夜日数(TN10p)、冷昼日数(TX10p)、DTR与之相反,作物生长期(GSL)、暖夜日数(TN90p)的气候倾向率以东北为中心向四周越来越大,霜冻日数(FD0)的气候倾向率以东北为中心向四周越来越小,极端降水指数1日最大降水量(RX1day)、中雨日数(R10)、强降水量(R95p)、最多连续有雨日数(CWD)的气候倾向率呈西北高、东南低的分布特点,TN90p、TN10p、CDD的变化速率最明显。极端气候事件与气温的升高和降水量的增加有明显的正相关性。

Based on the daily maximum and minimum temperature and precipitation data of 8 meteorological stations in Kaidou River-Kongque River Basin of Xinjiang from 1961 to 2019,the temporal and spatial variation characteristics of 18 extreme climate indicators were analyzed by means of univariate linear regression,Mann-Kendall mutation test,inverse distance weight interpolation and correla⁃tion analysis.The results showed that,from the aspect of time,the extreme high temperature indexes in most areas of Kaidou River-Kongque River Basin showed a significant upward trend,and the daily temperature range(DTR)and extreme low temperature index mainly showed a downward trend.The change of extreme precipitation indexes were not obvious,and the maximum number of consecu⁃tive dry days(CDD)showed a significant downward trend.The abrupt change time of extreme temperature was mainly from the late 1980s to the early 21st century,and the abrupt change year of extreme precipitation index was mainly from the 1980s to the early 1990s.From the aspect of space,climate tendency rate of the extreme temperature indexes including summer days(SU25),tropical nights(TR20),warm days(TX90p),warm spell duration(WSDI),ice days(ID0)showed the distribution characteristics of low in the northwest and high in the southeast,and cold spell duration index(CSDI),cold nights(TN10p),cold days(TX10p)and DTR were on the contrary;crop growth period(GSL),warm nights(TN90p)became larger and larger around the northeast and the number of frost days(FD0)beaome smaller and smaller around the northeast.The extreme precipitation indexes including the maximum 1-day precipitation(RX1day),the number of moderate rain days(R10),the heavy precipitation(R95p),the maximum consecutive wet days(CWD)showed the distribution characteristics of high in the northwest and low in the southeast.The change rate of TN90p,TN10p and CDD was the most obvious.Extreme weather events were significantly positively correlated with the increase of temperature and precipitation.