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Chinese Agricultural Science Bulletin ›› 2023, Vol. 39 ›› Issue (17): 72-78.doi: 10.11924/j.issn.1000-6850.casb2022-0508

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Variation Characteristics and Causes Analysis of Reference Crop Evapotranspiration in Congjiang County of Guizhou Province from 1971 to 2020

WEN Jianchuan1(), LIANG Ping2(), LIAO Yuling1, WU Hui1, Dong Wentao2   

  1. 1Congjiang County Meteorological Bureau, Qiandongnan, Guizhou 557400
    2Qiandongnan Prefecture Meteorological Bureau, Qiandongnan, Guizhou 556000
  • Received:2022-06-17 Revised:2022-08-09 Online:2023-06-15 Published:2023-06-12

Abstract:

The authors deeply analyzed the evolution trend of reference crop evapotranspiration (ET0) and influencing factors in Congjiang County, aiming to provide a basis for the management of farmland water resources. The daily ET0 in Congjiang County from 1971 to 2020 were analyzed by Penman-Monteith model, and then the periodic variation characteristics and the influence of climate factors on the ET0 were discussed by wavelet analysis and path analysis. The results showed that: from 1971 to 2020, the average annual ET0 of Congjiang County was 997.9 mm, which decreased significantly with a change rate of 10.11 mm/10 a, and the ET0 also showed a significantly decreasing trend in summer. The annual average ET0 showed an increasing-decreasing periodic variation alternating with a major cycle of 28 years, in which, the ET0 was high during 1983 to 1991 and 2003 to 2010, and the interdecadal change of ET0 in spring and summer also showed increasing-decreasing trends; sunshine hour was the main factor affecting the overall decline of ET0 in Congjiang County.

Key words: reference crop evapotranspiration, Penman-Monteith model, wavelet analysis, path analysis