近51年新疆S干旱指数变化特征分析

利用新疆地区52个气象站1960-2010年月降水量和无雨日数资料,定义了S干旱指数,采用EOF、REOF、Morlet小波分析、Mann-Kendall分析、分布函数等方法,分析了近51年来新疆干旱指数的时空分布特征。结果表明:EOF分解得出,新疆干旱指数存在三种主要的空间分布,即全区一致变化型、南北反向变化型和东西反向变化型;根据REOF前四个旋转荷载向量场高载荷区分布,将新疆干旱指数分成四个区,即新疆北部地区、新疆南部地区、天山中西部地区和天山东部地区;新疆北部地区、天山中西部地区和天山东部地区干旱指数有增大的总趋势,新疆南部地区干旱指数有减小的总趋势。

Study on the drought index variation for Xinjiang in recent 51 years

Based on the date of monthly precipitation and the number of rainless day at the 52 meteorological stations from 1960 to 2010 in Xinjiang,the S drought index is defined and the methods of EOF,REOF,inverse distance weighted,Morlet wavelet analysis,Mann-Kendall analysis,distribution function are employed to analyze the spatial and temporal variability of drought index.The results are as follows: The drought index presented three main patterns,that was the whole region consistent-type,the north-south opposite-type and east-west opposite-type.In addition,we divided Xinjiang into 4 different parts by drought index according to the high load area distribution of the first 4 revolving load vector fields,that was the North Area in Xinjiang,the South Area in Xinjiang,the Central and West Area in Tianshan and the East Area in Tianshan.Drought index increased in the North Area in Xinjiang,the Central and West Area in Tianshan and the East Area in Tianshan while it decreases in the South Area in Xinjiang.