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中国沙漠 ›› 2014, Vol. 34 ›› Issue (1): 244-253.DOI: 10.7522/j.issn.1000-694X.2013.00305

• 天气与气候 • 上一篇    下一篇

基于SPI指数的甘肃省河东地区干旱时空特征分析

王莺1, 李耀辉1, 胡田田2   

  1. 1. 中国气象局兰州干旱气象研究所 甘肃省干旱气候变化与减灾重点实验室/中国气象局干旱气候变化与减灾重点开放实验室, 甘肃 兰州 730020;
    2. 兰州大学 大气科学学院, 甘肃 兰州 730000
  • 收稿日期:2013-02-21 修回日期:2013-04-08 出版日期:2014-01-20 发布日期:2014-01-20
  • 作者简介:王莺(1984- ),女,甘肃兰州人,博士,助理研究员,主要从事气候变化对农业生态的影响研究。Email:wangyn924@163.com
  • 基金资助:
    国家重点基础研究发展计划项目(2013CB430200,2013CB430206);国家重大科学研究计划项目(2012CB955903);中国清洁发展机制基金项目(面向适应的气候灾害风险评估与管理机制研究);中国气象局兰州干旱气象研究所博士科研启动项目(KYS2012BSKYO2)资助

Analysis on Spatial and Temporal Patterns of Drought Based on Standardized Precipitation Index in the Hedong Area in Gansu Province

Wang Ying1, Li Yaohui1, Hu Tiantian2   

  1. 1. Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province/Key Open Laboratory of Arid Change and Disaster Reduction of CMA, Institute of Arid Meteorology, China Meteorological Administration, Lanzhou 730020, China;
    2. College of Atmospheric Science, Lanzhou University, Lanzhou 730000, China
  • Received:2013-02-21 Revised:2013-04-08 Online:2014-01-20 Published:2014-01-20

摘要: 干旱是西北地区主要的自然灾害之一。本文以甘肃省河东地区作为研究区,基于该地区38个气象站1971-2010年逐月降水数据计算标准化降水指数(SPI指数),分析了不同时间尺度SPI指数的时间序列特征,探讨了SPI3SPI12的年代际距平和倾向率的时空变化,以及特旱、重旱和中旱的发生频次。结果表明:(1)随着时间尺度的增加,SPI指数随机性在减弱,持续性在加强。干旱出现较多的时期为1991-2005年,出现较少的时期为1974-1982年。(2)20世纪80年代以前河东地区偏湿,90年代以后河东地区有偏干的趋势。河东地区行政区划分为7个部分,70-80年代,除甘南地区外,其余地区的SPI3倾向率均显著增加;80-90年代,河东地区SPI3倾向率持续减少,减少最明显的为定西地区;90年代到21世纪初,河东地区SPI3倾向率又有增加趋势。对于SPI12来说,自20世纪70年代到2010年,除甘南、陇南和天水地区的SPI12倾向率为先减少后增加以外,其余地区均呈现先增加,后减小,然后再增加的趋势。(3)3个月时间尺度干旱的分布范围广,发生频次高,主要发生于河东地区的北部。12个月时间尺度的特旱主要发生在河东地区的北部,重旱和中旱主要发生在河东地区的东部。

关键词: 标准化降水指数, 河东地区, 干旱

Abstract: Drought is one of the major natural disasters in Northwest China. Standardized precipitation index (SPI) under various temporal scales were calculated in the Hedong Area of Gansu Province with monthly precipitation data collected in 38 meteorological stations during 1971-2010. The patterns of SPI temporal series with different temporal scale were analyzed; the spatial and temporal changes in the decadal departure and tendency rate of SPI3 and SPI12 were discussed; the frequencies of extreme drought, severe drought and moderate drought were also addressed. Results showed that: (1) With the increase of temporal scale, the randomness of SPI weakened, and its consistence strengthened. There was a higher drought frequency in 1991-2005 than that in 1974-1982. (2) the Hedong Area was humid before 1980s, and then tended to be more arid after 1990s. For the 7 administrative districts in the Hedong Area during 1970s, there was a significant increase in the SPI3, except in Gannan region; during 1980s, there was a continuous decrement in the tendency rate of SPI3. For the tendency rate of SPI12 from 1970s to 2000s, the tendency rate decreased at first, and then increased, in Gannan, Longnan and Tianshui region, while other regions showed an opposite pattern. (3) There was wide spread and high frequency for drought events under three-month scale, which was concentrated in the northern part of Hedong Area. Under the twelve-month scale, extreme drought main occurred in the northern part of the Hedong Area, the severe and moderate drought mainly occurred in the eastern part of the Hedong Area.

Key words: standardized precipitation index (SPI), Hedong Area, drought

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