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Journal of Desert Research ›› 2022, Vol. 42 ›› Issue (6): 277-287.DOI: 10.7522/j.issn.1000-694X.2022.00051

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Groundwater evapotranspiration estimation based on soil moisture and water table measurements

Lin Li1,2(), Hu Liu1(), Chengpeng Sun1,2, Wenzhi Zhao1   

  1. 1.Linze Inland River Basin Research Station / Key Laboratory of Eco-Hydrology of Inland River Basin,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    2.University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2022-02-17 Revised:2022-03-23 Online:2022-11-20 Published:2023-01-09
  • Contact: Hu Liu

Abstract:

As one of the most important components of the vertical hydrological cycle in shallow groundwater environments and the major groundwater drainage mode naturally (>70%), the accurate estimation of groundwater evapotranspiration (ETg) is of great significance for the management of agriculture and water resources, reasonable protection and restoration of groundwater dependent vegetation in arid areas. Based on the water table and soil moisture fluctuation methods, ETg of Elaeagnus angustifolia. near Suolongtan Wetland in Linze County, Gansu Province during the 2017-2018 growing season (From April 15 to October 15) was estimated. The results showed that: (1) ETg was 275 mm and 511 mm in 2017 and 2018, accounting for 73% and 87% of actual evapotranspiration (ETg/ETa). Amount during July and August accounted for 48.2% and 48.4% of the total ETg in the whole growing season, which roughly coincided with the dynamics of groundwater depth and vegetation growth process. (2) ETg and its proportion in ETa are positively correlated with potential evapotranspiration, soil water storage and groundwater depth (P<0.05), the explained variances of the ETg by the three different factors are 48%, 21%, and 31% in 2017, and 24%, 24%, and 52% in 2018. (3) Data-driven method is feasible in the ETg quantitative evaluation of shallow groundwater environments in the desert oasis transition zone, but with relatively low temporal resolution, while data-driven method with mechanism modeling maybe a potential idea to improve the accuracy and resolution of ETg estimation in the study area.

Key words: groundwater evapotranspiration, water table fluctuations, soil moisture, data-driven method, arid region of northwest China

CLC Number: