Journal of Arid Meteorology ›› 2022, Vol. 40 ›› Issue (6): 1051-1058.DOI: 10.11755/j.issn.1006-7639(2022)-06-1051

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Spatial-temporal characteristics of drought in recent 50 years in Guangdong Province based on SPEI

YU Xingzhan1(), PU Yiliang2, KANG Boqian3   

  1. 1. Taishan Meteorological Bureau of Guangdong Province, Taishan 529200, Guangdong, China
    2. Jiangmen Meteorological Bureau of Guangdong Province, Jiangmen 529000, Guangdong, China
    3. Heshan Meteorological Bureau of Guangdong Province, Heshan 529700, Guangdong, China
  • Received:2022-01-21 Revised:2022-04-28 Online:2022-12-31 Published:2023-01-10

基于SPEI的广东省近50 a干旱时空特征

余兴湛1(), 蒲义良2, 康伯乾3   

  1. 1.广东省台山市气象局,广东 台山 529200
    2.广东省江门市气象局,广东 江门 529000
    3.广东省鹤山市气象局,广东 鹤山 529700
  • 作者简介:余兴湛(1991—),男,工程师,主要从事天气预报及气象服务.E-mail:526996271@qq.com
  • 基金资助:
    广东省江门市气象局科技项目(202105)

Abstract:

It is important to understand drought characteristics in Guangdong Province to reduce losses caused by drought. The monthly precipitation and temperature from 86 national meteorological stations in Guangdong Province from 1971 to 2020 are used to calculate the standardized precipitation evapotranspiration index (SPEI) at different time scales. Mann-Kendall trend test, empirical orthogonal function (EOF) and extreme-point symmetric mode decomposition (ESMD) methods are applied to analyze the spatial-temporal characteristics of drought in Guangdong Province in recent 50 years. The results show that the significant declining trend of annual scale SPEI indicates that drought is getting worse. Seasonal scale SPEI also shows a worse trend of drought but the trend is not significant. The occurring frequency of drought in Guangdong Province is high but the intensity of drought is weak. The first mode of EOF of annual scale SPEI shows that the whole Guangdong has experienced an evolution trend of drought or flood, and the corresponding time coefficient shows that Guangdong Province has a worse drought trend, which is closely related to the sea surface temperature in the east-central equatorial Pacific. The second mode of EOF of annual scale SPEI is closely related to the western Pacific subtropical high. The third mode of EOF of annual scale SPEI is significantly related to the land-sea contrasts. The ESMD analysis shows that the average annual scale SPEI is dominated by a 3.1-year period at inter-annual timescales and a 12.5-year period at the inter-decadal timescales. In addition, the trend residual R also indicates drought trend in Guangdong Province. In summary, the trend of drought in Guangdong Province is gradually prominent, which is characterized by high frequency and weak intensity of drought.

Key words: drought, Mann-Kendall trend test, EOF, ESMD, Guangdong Province

摘要:

了解广东省干旱特征对于减少旱灾损失具有重要意义基于1971—2020年广东省86个国家气象观测站逐月降水量和气温资料,计算不同时间尺度的标准降水蒸散指数(standardized precipitation evapotranspiration index,SPEI),利用Mann-Kendall趋势检验、经验正交函数(empirical orthogonal function,EOF)以及极点对称模态分解(extreme-point symmetric mode decomposition,ESMD)等方法,分析近50 a广东省干旱时空变化特征。结果表明:广东省年尺度SPEI整体呈较明显下降趋势,即干旱化趋势,四季也呈干旱化趋势,但并不明显。广东省干旱发生频率较高,但强度较低。EOF第一模态反映广东省存在一致变旱或变涝特征,其与赤道太平洋中东部海表温度关系更为密切,时间系数反映出广东省整体呈干旱化趋势;第二模态与西太平洋副热带高压关系较为密切;第三模态则与海陆差异有明显关联。ESMD分析表明广东省平均年尺度SPEI在年际上以3.1 a周期振荡为主,在年代际上以12.5 a周期振荡为主,趋势余量R反映广东省具有干旱化趋势。广东省整体有较明显干旱化趋势,干旱发生频率较高,但强度较低。

关键词: 干旱, Mann-Kendall趋势检验, EOF, ESMD, 广东省

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