Calibration of reference evapotranspiration models in Pará

ABSTRACT. The use of empirical agrometeorological models that can be adjusted to the climatic conditions of different regions has become increasingly necessary to improve water management in grain-producing municipalities. The aim of this work is to examine the correlation between various reference evapotranspiration (ETo) estimation methods and the standard FAO 56 Penman-Monteith method, as well as to determine correction factors, when necessary, for crop-producing municipalities in the northeast of Pará, during both the rainy and dry seasons. We compared simpler methods of ETo estimation to the FAO 56 Penman-Monteith method. For this purpose, meteorological data from Tracuateua, Bragança, Capitão Poço and Castanhal, provided by the National Institute of Meteorology (INMET), were used. The calibration of equations was performed through linear regression. The accuracy of different estimation methods was examined. The Turc, FAO 24 Blaney-Criddle and regression methods presented the best results for all statistical criteria; the Priestley-Taylor, Makkink and FAO 24 Radiation methods presented excellent results after calibration. The methods of Camargo and Hargreaves-Samani produced the worst results for all the criteria.摘要。为优化粮食产区的水资源管理，适配不同区域气候条件的经验性农业气象模型的应用需求日益增长。本研究旨在探讨帕拉州东北部粮食产区在雨季与旱季中，多种参考作物蒸散量（reference evapotranspiration, ETo）估算方法与标准FAO 56彭曼-蒙特斯方法的相关性，并在必要时确定校正系数。本研究将多种简易ETo估算方法与FAO 56彭曼-蒙特斯标准方法进行了对比。为此，本研究采用了巴西国家气象局（National Institute of Meteorology, INMET）提供的特拉克阿图阿、布拉甘萨、卡皮唐波索以及卡斯塔尼亚尔的气象数据。模型方程的校正通过线性回归方法完成。本研究对不同估算方法的精度进行了评估。在所有统计指标下，特尔克（Turc）法、FAO 24布兰尼-克里德尔（FAO 24 Blaney-Criddle）法以及回归法均表现最优；经校正后，普里斯特利-泰勒（Priestley-Taylor）法、马金克（Makkink）法与FAO 24辐射法也取得了优异结果。而卡马戈（Camargo）法与哈格雷夫斯-萨马尼（Hargreaves-Samani）法在所有指标下均表现最差。