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干旱区地理 ›› 2021, Vol. 44 ›› Issue (5): 1240-1249.doi: 10.12118/j.issn.1000–6060.2021.05.05

• 气候与水文 • 上一篇    下一篇

大理河流域干旱变化特征及其与极端降水的关系

邱德勋1,2(),穆兴民1,2,3,尹殿胜4,高鹏1,2,3()   

  1. 1.中国科学院水土保持研究所,黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西 杨凌 712100
    2.中国科学院大学,北京 100049
    3.西北农林科技大学,黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西 杨凌 712100
    4.中水淮河规划设计研究有限公司,安徽 合肥 230601
  • 收稿日期:2020-09-21 修回日期:2021-01-28 出版日期:2021-09-25 发布日期:2021-09-22
  • 通讯作者: 高鹏
  • 作者简介:邱德勋(1997-),男,研究生,硕士,主要从事水土保持与流域生态水文研究. E-mail: qiudexun97@163.com
  • 基金资助:
    国家重点研发计划专题计划(2016YFC0501707)

Variation characteristics of drought and its relationship with the extreme precipitation in Dali River Basin

QIU Dexun1,2(),MU Xingmin1,2,3,YIN Diansheng4,GAO Peng1,2,3()   

  1. 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, Shaanxi, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, Shaanxi, China
    4. China Water Huaihe Planning Design and Research Co., Ltd., Hefei 230601, Anhui, China
  • Received:2020-09-21 Revised:2021-01-28 Online:2021-09-25 Published:2021-09-22
  • Contact: Peng GAO

摘要:

基于标准化降水指数(SPI)方法,对1971-2017年大理河流域干旱变化特征及其与极端降水的联系进行了分析。结果表明:(1) 不同时间尺度SPI对降水量变化的敏感程度不同,SPI1和SPI3适用于短期气象旱涝特征的识别,而SPI6和SPI12对揭示区域长期旱涝影响及持续时间效果较好。2种时间尺度SPI(SPI3和SPI12)的时间变异性均呈显著增加趋势。(2) 不同季节SPI的变化趋势和干旱等级频次存在差异,仅冬季有一定的下降趋势,其余季节呈增加趋势,秋季最显著。年SPI波动幅度较大,总体上呈增加趋势,2001年以来最明显。干旱等级均以轻旱和中旱为主(21.2%~36.1%),夏、秋季发生干旱的频率最高。(3) 干旱事件持续时间呈不显著的减少趋势,长时间尺度干旱事件平均持续时间、最长持续时间以及下降速度均大于短时间尺度。(4) 降水集中程度增大会导致SPI1减小,增加干旱发生的可能性。典型极端降水可能会降低干旱发生的概率。

关键词: 降水, 干旱, 标准化降水指数(SPI), 大理河流域

Abstract:

The Dali River Basin is located in northwest China and is a typical fragile ecosystem area. This region is extremely sensitive to climatic changes, and monitoring these changes can therefore provide an important basis for decreasing the losses bought about by drought disasters. On the basis of the standard precipitation index (SPI), the variation in drought characteristics and their relationship with extreme precipitation events in the Dali River Basin from 1971 to 2017 were analyzed. The main results of this study suggest that (1) the annual precipitation initially showed an increasing trend (from 1971 to the early 1990s) and fluctuated before the mid-1990s before it decreased and then increased. The precipitation in the months from January to March, August, and December showed a downward trend, whereas the precipitation in the other months showed an upward trend, which was particularly notable for the month of September. SPI1 and SPI3 were suitable for identifying short-term meteorological drought and flood characteristics, whereas SPI6 and SPI2 were suitable for revealing the long-term impact and duration of regional droughts and floods. Temporal variations in the SPI (particularly SPI3 and SPI12) increased significantly. (2) However, the trend of the SPI and the frequency of drought grade differed through the seasons. In winter, there was a definite downward trend, whereas in the other seasons the trend was an increasing one, particularly in autumn. The interannual SPI fluctuated greatly, showing an increasing trend overall, particularly since 2001. Light drought and moderate drought were the predominant drought grades (21.2%-36.1%), and the frequency of drought in summer and autumn was the highest. (3) The average duration, longest duration, and descending speed of drought events at a long time scale were higher than those at a short time scale. In addition, the frequency of days with daily precipitation ≥0.1 mm was not significantly changed over the study duration, which indicates that the possibility of drought had not increased significantly in the Dali River Basin over the 47-year-range studied. (4) The increase in the precipitation concentration (Rmax/Rtotal) will lead to a decrease in SPI1 and will increase the possibility of drought. By contrast, an extreme precipitation will reduce the probability of drought. With the increase in the maximum daily precipitation (>50 mm), the annual SPI increased and reduced the possibility of drought.

Key words: precipitation, drought, standard precipitation index (SPI), Dali River Basin