Water requirements of olive orchards: I simulation of daily evapotranspiration for scenario analysis
Water requirements of olive orchards: I simulation of daily evapotranspiration for scenario analysis
复制标题
橄榄园需水量：模拟日蒸散量进行情景分析
DOI：
10.1007/s00271-005-0011-y
复制
发表时间：
2005
影响因子：
3
通讯作者：
E. Fereres
中科院分区：
文献类型：
--
作者：
L. Testi;F. Villalobos;F. Orgaz;E. Fereres
橄榄园的需水量很难计算，因为它们受到树龄、种植密度和灌溉系统等不同因素的影响。在这里，我们提出了一个橄榄水需要量模型，能够分别计算局部灌溉条件下土壤表面干湿部分的蒸腾作用(EP)、截留降雨蒸发作用(EPD)和土壤蒸发作用(ES)。该模型考虑了冠层尺寸对湿润土壤表面积EPand的影响。用涡旋协方差技术对一个发育中的橄榄园3年来的蒸散量(ET)进行了检验。预测的ET值和作物系数与实测值吻合较好。然后，利用西班牙科尔多瓦和美国加利福尼亚州弗雷斯诺的20年气象资料，利用该模型模拟了两个成熟果园的平均需水量。科尔多瓦−1果园300棵树的年平均ET值为1,025毫米，而弗雷斯诺同一果园的平均ET值为927毫米。蒸腾损失科尔多瓦为602毫米，弗雷斯诺为612毫米。土壤蒸发对橄榄蒸腾有很大影响；因此，橄榄作物系数(KC)对降雨量非常敏感。
Water requirements of olive orchards are difficult to calculate, since they are influenced by heterogeneous factors such as age, planting density and irrigation systems. Here we propose a model of olive water requirements, capable of separately calculating transpiration (Ep), intercepted rainfall evaporation (Epd) and soil evaporation (Es) from the wet and dry fraction of the soil surface under localized irrigation. The model accounts for the effects of canopy dimension onEpand of the wetted soil surface fraction onEs. The model was tested against actual measurements of olive evapotranspiration (ET) obtained by the eddy covariance technique in a developing olive orchard during 3 years. The predictedETand crop coefficients showed good agreement with the measured data. The model was then used to simulate the average water requirements of two mature orchards using 20-year meteorological datasets of Cordoba (Spain) and Fresno (CA, USA). Average annualETof a 300 trees ha−1orchard at Cordoba was 1,025 mm, while the same orchard at Fresno had an averageETof 927 mm. Transpiration losses were 602 mm at Cordoba and 612 mm at Fresno. Evaporation from the soil can have a large effect on oliveET; thus, olive crop coefficients (Kc) are very sensitive to the rainfall regime.