基于标准化降水指数的鲁西地区干旱时空特征分析

摘要

利用鲁西地区1962-2015年8个国家气象观测站逐月的降水资料,采用标准化降水指数(SPI)、主成分分析和ArcGIS空间插值方法,分析了该地区的年度和季节干旱演变特征.结果表明:(1)鲁西地区的干旱发生较为频繁且持续时间较长,年度和季节干旱发生频率均为30%左右,主要以轻旱和中旱为主,重旱和特旱发生频率较低;年度和季节的干旱站次比中,春旱和冬旱呈减少趋势,夏旱和秋旱呈增加趋势.(2)主成分分析中前两个特征向量的空间分布与干旱频率站次比的区域分布较为一致.%The annual and seasonal drought evolution characteristics in Western Shandong were analyzed based on the monthly precipitation data of 8 national meteorological stations from 1962 to 2015 by the standardized precipitation index (SPI), principal component analysis and spatial interpolation method of ArcGIS.The results showed that in Western Shandong, the drought had rather high occurrence frequency and lasted a long time.The annual and seasonal drought frequency fluctuated around 30%.The drought degree usually was light drought and moderate drought, and the heavy drought and excessive drought had lower occurrence frequency.In the station number ratio of annual and seasonal drought, the drought in spring and winter showed a decline trend, and the drought in summer and autumn showed an increase trend.The spatial distribution of the first two feature vectors in principal component analysis was in accordance with the regional distribution of station number ratio of drought frequency.