基于标准化降水指数分析鄂尔多斯市干旱演化特征

The Evolution Characteristics of Droughts Based on Standard Precipitation Index in Erdos

利用鄂尔多斯市1961—2010年11个气象站的逐月降水资料,通过标准化降水指数分析鄂尔多斯市近50a来干旱的时空演化特征。结果表明:鄂尔多斯市干旱的发生在时间序列上具有阶段性特征,20世纪60年代前期和90年代末期干旱最为严重,80年代为持续性干旱阶段。用经验正交函数对鄂尔多斯市干旱的空间分布特征做进一步分析,结果表明,鄂尔多斯市干旱的空间分布既有显著的一致性,又有一定的区域性。将鄂尔多斯市具体细分为西北部、东北部、西南部、东南部4个区域,80年代之前,东北部干旱较为严重,80年代以后西部干旱化趋势加剧,西北部尤为明显,东部降水增多。

Using monthly rainfall data of I I weather stations from 1961 to 2010 in Erdos and based on the stan- dard precipitation index, the temporal-spatial evolution characteristics of droughts over the past 50 years in Erdos are studied. The results indicated that droughts occurrence of Erdos showed stage features： The drought is more severe in earlier1960s and tile late 1990s.h is a persistent drought stage in 1980s.The spatial distribution charac- teristic of drought in Erdos are further analyzed by means of the principal component analysis method. The result showed the spatial distribution of droughts was significantly consistent, but there existed regional different. The Erdos is divided into 4 areas： northwest, northeast, southwest and southeast,The results is that the droughts is more severe in northeast before 1980, The droughts of western has shown as increasing trend, especially in northwest. The precipitation increased in east.