ISSN 1000-3665 CN 11-2202/P

    地下水埋深对淮北平原冬小麦耗水量影响试验研究

    An experimental study of the influence of groundwater level on water consumption of winter wheat in the Huaibei Plain

    • 摘要: 研究地下水埋深对淮北平原冬小麦耗水量的影响,对浅埋区农业水管理具有重要意义。基于2017—2020年五道沟水文水资源实验站大型称重式蒸渗仪群,模拟不同地下水埋深下冬小麦蒸散发变化过程,以蒸散量表征小麦耗水的变化,识别影响小麦耗水的关键环境因子,探索不同情景小麦耗水特征。全生育期内各地下水埋深0.5,1.0,2.0,3.0 m下小麦蒸散量依次为510.50,499.33,567.88,727.88 mm,各埋深下表层10 cm处土壤含水率与蒸散量相关系数依次为−0.42,−0.69,−0.53,−0.43;依据太阳辐射量划分3类典型日,典型日内蒸散强度为:强辐射日约0.30 mm/h、弱辐射日约0.07 mm/h、微弱辐射日约0.03 mm/h;蒸散峰历时依次为:5:00—20:00、7:00—17:00和9:00—17:00;太阳辐射强时,地下水埋深对蒸散强度峰值出现的时间影响较小,而太阳辐射过弱时,地下水埋深大会阻滞能量传输,蒸散强度峰值滞后;表层土壤水是蒸散发的主要来源,尤其在1.0,2.0 m埋深下表层土壤水对蒸散发贡献率更高;太阳辐射、净辐射和土壤热通量正向驱动小麦耗水,表层土壤水分、平均气温和空气湿度反向驱动。

       

      Abstract: The influence of groundwater level on water consumption of winter wheat in the Huaibei plain is examined, which is key for agricultural water management. Based on the group of large weighing lysimeters in the Wudaogou Hydrology and Water Resources experimental station from 2017 to 2020, the wheat evapotranspiration at various groundwater levels is simulated and the key environmental factors affecting wheat evapotranspiration are identified for the purpose of exploring the characteristics of wheat evapotranspiration. During the whole growth period, the wheat evapotranspiration at four groundwater levels (depth of 0.5, 1.0, 2.0 and 3.0 m) is 510.50, 499.33, 567.88, 727.88 mm, respectively. The correlation coefficient between surface soil moisture and evapotranspiration under each groundwater level is −0.51, −0.71, −0.62 and −0.72, respectively. According to the classified categories by solar radiation, three typical days are chosen with the corresponding evapotranspiration intensity of 0.30 mm/hin the strong radiation day, of 0.07 mm/h in weaker radiation day, and of 0.03 mm/h in the weakest radiation day. The peak of evapotranspiration intensity happens from 5:00 to 20:00 in the strong radiation day, from 7:00 to 17:00 in the weaker radiation day, and from 9:00 to 17:00 in the weakest radiation day. The stronger the solar radiation, the weaker the influence of groundwater level on the peak of evapotranspiration intensity. This is probably because the large groundwater levelmay block energy transmission so that the peak of evapotranspiration intensity lags behind. Surface soil is the main source of evapotranspiration, especially at depth of 1.0 and 2.0 m. Simultaneously, solar radiation, net radiation and soil heat flux drive wheat evapotranspiration positively, while surface soil moisture, average air temperature and air humidity drive contrariwise.

       

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