中文摘要：

干旱指数反映了气候的干旱程度，干旱指数的年际变化能够体现一个地区气候的演变．吉林西部降水不足，蒸发量大，干旱程度逐渐加剧．应用分形理论，首先进行了吉林西部1951-2003年共53a干旱指数的R／S分析，计算出Hurst系数，结果表明吉林西部的干旱指数在时间序列上具有显著的自相似性．在此基础上，应用连续变维分形模型预测了2004—2023年的干旱指数，结果表明该区气候将继续向干旱的趋势发展．

英文摘要：

The degree of drought was reflected by drought index. The change of annual drought index could reflect the evolvement of climate in an area. There was a lack of precipitation and a lot of evaporation, the degree of drought was pricked up gradually in the west of Jilin Province. In this paper, on base of fractal theory,R/S analysis of drought index from 1951 to 2003 in the west of Jilin Province was carried out,and then the Hurst coefficient was calculated. The result showed that there was an obvious self-comparability on time sequence ofthe drought index in the area. After that, the drought indexes from 2004 to 2023 in this area were forecasted by the model of variable dimension fraction. The result showed that it would keep on drought in the future in the west of Jilin Province.