摘要
干旱对水文循环、生态系统、工农业生产及社会生活具有重要影响。为此,基于标准化降水蒸散指数(SPEI),分析了湖北省近50年不同时间尺度干旱演变特征。结果表明:不同时间尺度干湿变化频率、持续时间、干旱强度、发生范围存在明显差异,但其年际变化特征基本一致,程度略有差异。在6个月及更长时间尺度上,20世纪60年代前期、70年代前期及80年代至90年代前期是湖北省较为湿润的时期,20世纪90年代后期以来尤其是21世纪初的10年湿期明显减少,干期明显增加;在季节尺度上,近50年湖北省春、秋季呈干旱化趋势,夏、冬季呈湿润化趋势,其中秋季干旱化趋势最为显著;1个月时间尺度干湿变化阶段性、趋势性特征最不明显。各时间尺度干旱发生强度均有加重趋势,最严重干旱事件集中发生在近20年。干旱发生范围时间序列变化与干期阶段变化的特征非常一致,其中极端干旱在近10年大范围发生的频率显著高于过去40年。
Drought has significant impact on hydrological cycle,ecosystems,agricultural production and social life,thus requiring special attention.The characteristics of drought over a range of time scales were examined in Hubei Province in the past 50 years,using the standardized precipitation evapotranspiration index（SPEI） as an indicator of drought severity.The results showed that the frequency,duration,intensity and spatial extent of drought at different time scales were notably different,while the evolution characteristics of drought from different years were similar.At the time scale of 6 months or longer,wet periods were recognized in the early 60s,early 70s,80s and early 90s in the 20th century,while since the late 90s especially the 21st the frequency of wet periods has decreased and of dry periods increased significantly.At the seasonal timescale,there was a drying trend for spring and autumn and minor wetting trend for summer and winter,among which the drying trend in autumn was statistically significant at 0.05 levels of significance.At the time scale of 1 month,the SPEI was so unstable that no trend or periodical characteristic was found.Over all the time scales,drought intensity has experienced an increasing tendency over the past 50 years,with the most severe droughts occurring in the last 20 years;drought spatial extent has changed in accordance with the variation of dry periods,but with a more distinct increase of large scale extreme drought in the last 10 years than in the past 40 years.
出处
《中国农学通报》
CSCD
2012年第29期279-284,共6页
Chinese Agricultural Science Bulletin
基金
气候变化专项"气候变化对长江中游典型湖泊湿地的影响"(CCSF201205)
关键词
标准化降水蒸散指数
多时间尺度
干旱
standardized precipitation evapotranspiration index（SPEI）
different time scales
drought
