基于SPI的怀化市气象干旱时空特征分析

Spatial and temporal characteristics of meteorological drought in Huaihua City based on SPI

基于标准化降水指数(SPI),采用线性趋势分析、滑动平均、空间分析等方法对怀化市1962—2015年气象干旱特征进行分析,结果表明:1962—2015年怀化市年尺度整体干旱频率(轻旱及以上干旱发生频率)为29.6%,中旱频率14.8%,重旱频率5.6%,特旱频率3.7%。1962—2015年怀化市年干旱强度(SPI)在-2.5~1.9之间,年际变化趋势不显著,从四季来看,秋旱最为严重。

Based on the standardized precipitation index(SPI),the meteorological drought characteristics of Huaihua City from 1962 to 2015 were analyzed by means of linear trend analysis,moving average analysis and spatial analysis.The results show that:①the annual overall drought frequency(light drought and above drought frequency)was 29.6%,the moderate drought frequency was 14.8%,the severe drought frequency was 5.6%,and the extraordinary drought frequency was 3.7%.②From 1962 to 2015,the annual drought intensity(SPI)of Huaihua City ranged from-2.5 to 1.9,with no significant interannual change trend,and autumn drought was the most serious in the four seasons.