地理科学进展

地理科学进展 ›› 2011, Vol. 30 ›› Issue (3): 299-305.doi: 10.11820/dlkxjz.2011.03.006

• 气候变化 • 上一篇    下一篇

石羊河流域极端干旱事件的时空变化特征

王兴梅1, 张勃1, 张凯2, 张调风1, 戴声佩1, 王亚敏1, 李丹1   

  1. 1. 西北师范大学地理与环境科学学院，兰州730070;
    2. 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，兰州730000
  • 收稿日期:2010-10-01 修回日期:2011-01-01 出版日期:2011-03-25 发布日期:2011-03-25
  • 作者简介:王兴梅(1984-)，女，甘肃民勤人，硕士研究生，主要从事气候变化、资源与环境研究。E-mail: xingmeiyifan@163.com
  • 基金资助:

    国家自然科学基金项目(40961038)；公益性行业(气象)科研专项(GYHY200806021-07)；中国科学院知识创新工程重要方向项目(KZCX2-YWQ10-4)；甘肃省自然科学基金项目(3ZS061-A25-009)；生态经济学甘肃省级重点学科项目(5001-063)。

The Spatial and Temporal Characteristics of Extreme Drought Events in Shiyang River Basin

WANG Xingmei1, ZHANG Bo1, ZHANG Kai2, ZHANG Tiaofeng1, DAI Shengpei1, WANG Yamin1, LI Dan1   

  1. 1. Geographic and Environmental Sciences Department of Northwest Normal University, Lanzhou 730070, China;
    2. Key Laboratory of Arid Climatic Changing and Reducing Disaster of Gansu Province, Key Open Laboratory of Arid Climate Change and Disaster Reduction of CMA, Institute of Arid Meteorology, China Meteorological Administration, Lanzhou 730020, China
  • Received:2010-10-01 Revised:2011-01-01 Online:2011-03-25 Published:2011-03-25

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摘要： 本文借助ArcGIS 9.2 和Matlab 7.0 数据软件平台，运用复值Morlet 小波分析和数理统计方法对石羊河流域极端干旱事件在时空上的变化特征进行分析，结果表明：①石羊河流域的平均湿润指数自北向南逐渐增大，其湿润指数与年均降水和海拔高度具有显著正相关性(在0.01 置信水平)，而与年均蒸发具有显著负相关性(在0.05 置信水平)。②在时间尺度上来说，极端干旱事件的频数具有19a、9a、6a、4a、15a 的周期，可能是受南亚高压的准3 年周期的影响；在空间尺度上来说，极端干旱事件频数与湿润指数的空间分布大体相似，略有不同是两者的最小值不同：即地表湿润指数最小值在民勤，而极端干旱事件发生频数最小值在武威。7-9 月份发生极端干旱频数占年极端干旱总频数的60.62%。③年极端干旱总频数和7-9 月份极端干旱总频数都呈略微上升趋势，且年极端干旱频数的线性倾向率较大，即将达到0.3/10a。通过Pettitt 突变检验法对年极端干旱总频数和7-9 月份极端干旱总频数进行检测，结果检验到突变点分别为2000年和1983 年(在0.01 置信水平)。

关键词: 极端干旱, 湿润指数, 石羊河流域, 时空特征

Abstract: With global warming, hot days and warm nights have significantly increased，but cold days and cold nights have decreased, and the frequency of extreme weather and climate events has significantly increased. Climate warming has four major challenges for our economy to face, of which the first challenge is the extreme weather events. The frequency of extreme weather events is getting bigger, with a tendency of getting stronger. Drought in global warming becomes more prominent and sensitive, and is one of the key and hot issues in climate change research. This paper analyzes the spatial and temporal characteristics of extreme drought events in Shiyang River Basin, combining ArcGIS 9.2 and Matlab 7.0 data software platform and using complex Morlet wavelet analysis and mathematical statistical theory. The results show that: (1) the average humidity index increases gradually from north to south in Shiyang Basin, and annual precipitation and altitude have significant positive correlations with the moisture index (0.01 confidence level), while the annual evaporation has a significant negative correlation (0.05 confidence level). (2) From the time point of view, the cycle with extreme drought is 19a, 9a, 6a, 4a and 15a, which may be affected by the South Asia High pressure with a three-year cycle. In spatial scale, the spatial distributions of the extreme drought frequency and surface moisture index are broadly similar, with slight difference, of which the lowest extreme drought frequency is in the Wuwei region, and the humid index in Minqin is the smallest in the study area. Furthermore, the extreme drought events occur mainly from July to September, and the extreme droughts frequency of this period accounts for 60.62% of the total frequency throughout the year. (3) The annual and July-September extreme drought frequencies show a slight upward trend, and the linear trend of the annual frequency is obvious to reach about 0.3/10a. The sudden change of the annual and July-September of extreme droughts frequency can be detected by the Pettitt mutation test, which occurred respectively in 2000 and 1983 (0.01 confidence level).

Key words: extreme drought, humid index, Shiyang River Basin, spatial and temporal characteristics