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 .

P426.616