1984-2019年广西地区极端气候指数时空变化

Study on the Spatiotemporal Variation Characteristics of Extreme Climate Index in Guangxi

利用RClim Dex模型对广西地区18个气象站点1984-2019年日最高、日最低温度,以及降水时间序列数据计算广西地区的极端气候指数,趋势分析法、M-K突变检验法和反距离加权插值法(IDW)定量研究广西地区极端气候指数时空变化特征研究。结果显示,广西地区极端气温指数年际变化总体上呈现高温类指数TXx,TNn,TNx,TX_(90),TN_(90),WSDI,TR,SU上升趋势,低温类指数TXn,TN 10,TX 10,CSDI,GSL,DTR下降趋势。1987-2009年突变频率具有随机性,2009年之后频率频率高,日最低气温最大值TNx、昼暖日数TX_(90)、暖夜日数TN_(90)以及热夜日数TR没有发生突变。空间格局总体上变化趋势为东部向西部递减,与之相对指数相反。极端降水指数指数总体呈现上升趋势,其中PRCPTOT、SDII、CWD、Rx1day、Rx5day、R_(95)、R_(99)、R_(10) mm、R_(20) mm、R_(25) mm呈上升趋势,仅连续无雨日数CDD呈下降趋势,数突变年份主要集中在1991和2001年,其余年份突变较为随机;空间格局总体上为西部降水量下降,干旱程度比东部高,东部降水量呈上升。

The RclimDex model was used to calculate the extreme climate index of Guangxi from 1984 to 2019 based on the daily maximum and minimum temperature and precipitation time series data of 18 meteorological stations in Guangxi.The trend analysis method,M-K mutation test method and inverse distance weighted interpolation method(IDW)were used to quantitatively study the spatio-temporal variation characteristics of the extreme climate index in Guangxi.Results show that extreme temperatures in Guangxi region overall interannually present an upwardtrend of high-temperature-classindexesTXx,TNn,TNx,TX_(90),TN_(90),WSDI,TR,SU while low-temperature-class indicesTXn,TN 10,TX 10,CSDI,GSL,DTR decline.Themutation frequency during 1987-2009 was random,and the frequency was high after 2009.The maximumdaily-minimum temperature TNx,the number of warm-day days TX_(90),the number of warm-night days TN90 and the number of hot-night days TR did not have mutations.The overall trend of spatial pattern is decreasing from east to west,which is opposite to its relative index.The extreme precipitation index showed an upward trend in general,among which PRCPTOT,SDII,CWD,Rx1day,Rx5day,R_(95),R_(99),R_(10) mm,R_(20) mm and R_(25) mm showed an upward trend,and only the number of consecutive days without rain CDD showed a downward trend,and the number of abrupt changes was mainly concentrated in 1991 and 2001.The mutations in other years were random.The spatial pattern is that the precipitation in the west decreases,the drought degree is higher than that in the east,and the precipitation in the east increases.