基于K干旱指数的朝阳地区干旱气象分析

K Index Based Drought Climate Analysis in Chaoyang District

利用1960—2013年朝阳地区5个气象站的降水量和蒸发量数据,计算K干旱指数,分析朝阳地区的干旱情况。结果表明:朝阳地区常年处于轻中旱的旱象之中,全年干旱指数呈上升趋势,上升幅度为0.046 2/10 a,仅20世纪90年代呈下降趋势,而20世纪80年代上升最为明显,春季干旱指数明显上升,夏季和秋季有小幅度上升,冬季呈下降趋势。朝阳地区的全年干旱指数,自20世纪80年代末以来有明显的上升趋势,是从1985年的突变现象开始,到20世纪90年代末增长趋势最为显著。在过去54 a间,朝阳地区干旱指数共有4次突变。春季的朝阳地区,从1977年一次突变现象开始干旱指数就呈上升趋势,20世纪80年代末开始上升趋势持续显著,夏秋冬季突变现象较多,UF和UB曲线呈震荡状态,都存在短时期的下降趋势,但干旱指数基本维持着小幅增长趋势。

This paper use the rainfall and evaporation data of five weather stations in Chaoyang from 1960 to 2013, it calculates K drought index, analysises drought conditions in Chaoyang district. The result shows that Chaoyang is in light drought. Drought index for the whole year is on the rise, and rise to 0.0462/10. Only a downward trend is in the 90 s, while the rise in the 80 s is the most obvious. The spring drought index rise obviously,and a small increase is in summer and autumn, the winter is on the decline. The whole year drought index of chaoyang district, since the late 80 s has a rising trend, started in 1985 with a mutation phenomenon, by the end of the 90 s growth trend is most significantly. In the past 54 years, drought index has four mutations in Chaoyang. In spring, drought index is on the rise by a mutation phenomenon from 1977, and in the late 80 s began to rise significantly. From summer to winter, mutation phenomenon is more. UF and UB curve is in a state of shock. There are short of decline from summer to winter, but drought index basically maintains small growth trend.