1961-2013年山西省极端气候事件时空演变特征

Temporal and spatial analysis of extreme climatic events in Shanxi Province from 1961 to 2013

利用中国气象局整编的山西18个台站1961-2013年的逐日气温、降水数据,采用极端事件定义方法和Mann-kendall突变检验等方法,计算与植被生长的水热条件与寒旱灾害直接相关的极端气候事件指数,分析1961-2013年山西省极端温度和降水气候事件的时空演变特征。结果表明,研究区极端温度事件的发生频率与持续时间在前30年呈平稳态势,20世纪90年代后变化迅速。表征极端低温事件的霜日日数(FD0)、冷昼日数(TX10P)、冷夜日数(TN10P)、冷持续指数(CSDI)等指数均呈现下降趋势,而表征极端高温事件的夏日指数(SU25)、作物生长期(GSL)、暖昼日数(TX90P)、暖夜日数(TN90P)、热持续指数(WSDI)则均呈上升趋势。极端降水指数除普通日降水强度(SDII)和持续干燥指数(CDD)外均呈下降趋势,表明该地降水总量略有减少,但降水强度和持续干燥指数却有所增加。与极端高温事件发生频率的加剧出现在90年代初不同,表征强降水事件发生频率和强度的极端降水指标的显著变化发生在70年代。在空间尺度上,与温度相关的极端气温指数呈现出由南向北递减的分布规律,冷、暖系列指数表明晋南地区最高,晋北地区最低。与降水量相关的极端降水指数也呈南高北低的规律,最近一个时段的强降水事件有所增加。

Based on daily data for temperature and precipitation from 18 meteorological stations in Shanxi,China from 1961 to 2013 and extreme events define methods and Mann-Kendall Jump tests,16 indexes that characterize the frequency and probability of extreme climatic events were calculated using Rclim Dex（1.0）. The trends and spatial patterns of extreme climatic events across this region were obtained. The results indicate that the frequency and duration of extreme temperature events increased since the 1990 s in comparison with smooth trends from the 1960 s to the late 1980 s. Frost day（FD0）,the percentile value of cold night（TN10P）,the percentile value of cold day（TX10P）and the duration of coldness（CSDI）characterizing extremely low temperatures presented downward trends;meanwhile,summer day（SU25）,crop growth period（GSL）,the percentile value of warm night,the percentile value of warm day（TX90P）and the duration of warmness（WSDI）characterizing extremely high temperatures showed upward trends. Extreme precipitation indexes,except SDII and CDD,showed downward trends during the past 53 years.Precipitation in the study area decreased slightly while the intensity of precipitation and continued dry index increased. Extreme precipitation index characterizing the frequency and intensity of heavy precipitation has had obvious change since the 1970 s,while the extreme temperature events have undergone a sharp jump since the 1990 s. Additionally,extreme temperature and precipitation indices show clear spatial distributions decreasing from south to north. Cold and warm series indices showed that the highest value lies in southern Shanxi;heavy precipitation events increased recently.